Extended maintenance of Ruby 1.9.3 ended on February 23, 2015. Read more
A String
object holds and manipulates an arbitrary sequence of
bytes, typically representing characters. String
objects may be created using String::new
or as literals.
Because of aliasing issues, users of strings should be aware of the methods
that modify the contents of a String
object. Typically,
methods with names ending in “!” modify their receiver, while those without
a “!” return a new String
. However, there are exceptions,
such as String#[]=
.
Returns a new string object containing a copy of str.
static VALUE rb_str_init(int argc, VALUE *argv, VALUE str) { VALUE orig; if (argc > 0 && rb_scan_args(argc, argv, "01", &orig) == 1) rb_str_replace(str, orig); return str; }
Format—Uses str as a format specification, and returns the result
of applying it to arg. If the format specification contains more
than one substitution, then arg must be an Array
or
Hash
containing the values to be substituted. See
Kernel::sprintf
for details of the format string.
"%05d" % 123 #=> "00123" "%-5s: %08x" % [ "ID", self.object_id ] #=> "ID : 200e14d6" "foo = %{foo}" % { :foo => 'bar' } #=> "foo = bar"
static VALUE rb_str_format_m(VALUE str, VALUE arg) { volatile VALUE tmp = rb_check_array_type(arg); if (!NIL_P(tmp)) { return rb_str_format(RARRAY_LENINT(tmp), RARRAY_PTR(tmp), str); } return rb_str_format(1, &arg, str); }
Copy—Returns a new String
containing integer copies
of the receiver.
"Ho! " * 3 #=> "Ho! Ho! Ho! "
VALUE rb_str_times(VALUE str, VALUE times) { VALUE str2; long n, len; char *ptr2; len = NUM2LONG(times); if (len < 0) { rb_raise(rb_eArgError, "negative argument"); } if (len && LONG_MAX/len < RSTRING_LEN(str)) { rb_raise(rb_eArgError, "argument too big"); } str2 = rb_str_new5(str, 0, len *= RSTRING_LEN(str)); ptr2 = RSTRING_PTR(str2); if (len) { n = RSTRING_LEN(str); memcpy(ptr2, RSTRING_PTR(str), n); while (n <= len/2) { memcpy(ptr2 + n, ptr2, n); n *= 2; } memcpy(ptr2 + n, ptr2, len-n); } ptr2[RSTRING_LEN(str2)] = '\0'; OBJ_INFECT(str2, str); rb_enc_cr_str_copy_for_substr(str2, str); return str2; }
Concatenation—Returns a new String
containing
other_str concatenated to str.
"Hello from " + self.to_s #=> "Hello from main"
VALUE rb_str_plus(VALUE str1, VALUE str2) { VALUE str3; rb_encoding *enc; StringValue(str2); enc = rb_enc_check(str1, str2); str3 = rb_str_new(0, RSTRING_LEN(str1)+RSTRING_LEN(str2)); memcpy(RSTRING_PTR(str3), RSTRING_PTR(str1), RSTRING_LEN(str1)); memcpy(RSTRING_PTR(str3) + RSTRING_LEN(str1), RSTRING_PTR(str2), RSTRING_LEN(str2)); RSTRING_PTR(str3)[RSTRING_LEN(str3)] = '\0'; if (OBJ_TAINTED(str1) || OBJ_TAINTED(str2)) OBJ_TAINT(str3); ENCODING_CODERANGE_SET(str3, rb_enc_to_index(enc), ENC_CODERANGE_AND(ENC_CODERANGE(str1), ENC_CODERANGE(str2))); return str3; }
Append—Concatenates the given object to str. If the object is a
Integer
, it is considered as a codepoint, and is converted to
a character before concatenation.
a = "hello " a << "world" #=> "hello world" a.concat(33) #=> "hello world!"
VALUE rb_str_concat(VALUE str1, VALUE str2) { unsigned int code; rb_encoding *enc = STR_ENC_GET(str1); if (FIXNUM_P(str2) || TYPE(str2) == T_BIGNUM) { if (rb_num_to_uint(str2, &code) == 0) { } else if (FIXNUM_P(str2)) { rb_raise(rb_eRangeError, "%ld out of char range", FIX2LONG(str2)); } else { rb_raise(rb_eRangeError, "bignum out of char range"); } } else { return rb_str_append(str1, str2); } if (enc == rb_usascii_encoding()) { /* US-ASCII automatically extended to ASCII-8BIT */ char buf[1]; buf[0] = (char)code; if (code > 0xFF) { rb_raise(rb_eRangeError, "%u out of char range", code); } rb_str_cat(str1, buf, 1); if (code > 127) { rb_enc_associate(str1, rb_ascii8bit_encoding()); ENC_CODERANGE_SET(str1, ENC_CODERANGE_VALID); } } else { long pos = RSTRING_LEN(str1); int cr = ENC_CODERANGE(str1); int len; char *buf; switch (len = rb_enc_codelen(code, enc)) { case ONIGERR_INVALID_CODE_POINT_VALUE: rb_raise(rb_eRangeError, "invalid codepoint 0x%X in %s", code, rb_enc_name(enc)); break; case ONIGERR_TOO_BIG_WIDE_CHAR_VALUE: case 0: rb_raise(rb_eRangeError, "%u out of char range", code); break; } buf = ALLOCA_N(char, len + 1); rb_enc_mbcput(code, buf, enc); if (rb_enc_precise_mbclen(buf, buf + len + 1, enc) != len) { rb_raise(rb_eRangeError, "invalid codepoint 0x%X in %s", code, rb_enc_name(enc)); } rb_str_resize(str1, pos+len); strncpy(RSTRING_PTR(str1) + pos, buf, len); if (cr == ENC_CODERANGE_7BIT && code > 127) cr = ENC_CODERANGE_VALID; ENC_CODERANGE_SET(str1, cr); } return str1; }
Comparison—Returns -1 if other_str is greater than, 0 if
other_str is equal to, and +1 if other_str is less than
str. If the strings are of different lengths, and the strings are
equal when compared up to the shortest length, then the longer string is
considered greater than the shorter one. In older versions of Ruby, setting
$=
allowed case-insensitive comparisons; this is now
deprecated in favor of using String#casecmp
.
<=>
is the basis for the methods <
,
<=
, >
, >=
, and
between?
, included from module Comparable
. The
method String#==
does not use Comparable#==
.
"abcdef" <=> "abcde" #=> 1 "abcdef" <=> "abcdef" #=> 0 "abcdef" <=> "abcdefg" #=> -1 "abcdef" <=> "ABCDEF" #=> 1
static VALUE rb_str_cmp_m(VALUE str1, VALUE str2) { long result; if (TYPE(str2) != T_STRING) { if (!rb_respond_to(str2, rb_intern("to_str"))) { return Qnil; } else if (!rb_respond_to(str2, rb_intern("<=>"))) { return Qnil; } else { VALUE tmp = rb_funcall(str2, rb_intern("<=>"), 1, str1); if (NIL_P(tmp)) return Qnil; if (!FIXNUM_P(tmp)) { return rb_funcall(LONG2FIX(0), '-', 1, tmp); } result = -FIX2LONG(tmp); } } else { result = rb_str_cmp(str1, str2); } return LONG2NUM(result); }
Equality—If obj is not a String
, returns
false
. Otherwise, returns true
if str
<=>
obj returns zero.
VALUE rb_str_equal(VALUE str1, VALUE str2) { if (str1 == str2) return Qtrue; if (TYPE(str2) != T_STRING) { if (!rb_respond_to(str2, rb_intern("to_str"))) { return Qfalse; } return rb_equal(str2, str1); } return str_eql(str1, str2); }
Equality—If obj is not a String
, returns
false
. Otherwise, returns true
if str
<=>
obj returns zero.
VALUE rb_str_equal(VALUE str1, VALUE str2) { if (str1 == str2) return Qtrue; if (TYPE(str2) != T_STRING) { if (!rb_respond_to(str2, rb_intern("to_str"))) { return Qfalse; } return rb_equal(str2, str1); } return str_eql(str1, str2); }
Match—If obj is a Regexp
, use it as a pattern to
match against str,and returns the position the match starts, or
nil
if there is no match. Otherwise, invokes obj.=~,
passing str as an argument. The default =~
in
Object
returns nil
.
"cat o' 9 tails" =~ /\d/ #=> 7 "cat o' 9 tails" =~ 9 #=> nil
static VALUE rb_str_match(VALUE x, VALUE y) { switch (TYPE(y)) { case T_STRING: rb_raise(rb_eTypeError, "type mismatch: String given"); case T_REGEXP: return rb_reg_match(y, x); default: return rb_funcall(y, rb_intern("=~"), 1, x); } }
Element Reference—If passed a single Fixnum
, returns a
substring of one character at that position. If passed two
Fixnum
objects, returns a substring starting at the offset
given by the first, and with a length given by the second. If passed a
range, its beginning and end are interpreted as offsets delimiting the
substring to be returned. In all three cases, if an offset is negative, it
is counted from the end of str. Returns nil
if the
initial offset falls outside the string or the length is negative.
If a Regexp
is supplied, the matching portion of str
is returned. If a numeric or name parameter follows the regular expression,
that component of the MatchData
is returned instead. If a
String
is given, that string is returned if it occurs in
str. In both cases, nil
is returned if there is no
match.
a = "hello there" a[1] #=> "e" a[2, 3] #=> "llo" a[2..3] #=> "ll" a[-3, 2] #=> "er" a[7..-2] #=> "her" a[-4..-2] #=> "her" a[-2..-4] #=> "" a[12..-1] #=> nil a[/[aeiou](.)\1/] #=> "ell" a[/[aeiou](.)\1/, 0] #=> "ell" a[/[aeiou](.)\1/, 1] #=> "l" a[/[aeiou](.)\1/, 2] #=> nil a["lo"] #=> "lo" a["bye"] #=> nil
static VALUE rb_str_aref_m(int argc, VALUE *argv, VALUE str) { if (argc == 2) { if (TYPE(argv[0]) == T_REGEXP) { return rb_str_subpat(str, argv[0], argv[1]); } return rb_str_substr(str, NUM2LONG(argv[0]), NUM2LONG(argv[1])); } if (argc != 1) { rb_raise(rb_eArgError, "wrong number of arguments (%d for 1..2)", argc); } return rb_str_aref(str, argv[0]); }
Element Assignment—Replaces some or all of the content of str. The
portion of the string affected is determined using the same criteria as
String#[]
. If the replacement string is not the same length as
the text it is replacing, the string will be adjusted accordingly. If the
regular expression or string is used as the index doesn’t match a position
in the string, IndexError
is raised. If the regular expression
form is used, the optional second Fixnum
allows you to specify
which portion of the match to replace (effectively using the
MatchData
indexing rules. The forms that take a
Fixnum
will raise an IndexError
if the value is
out of range; the Range
form will raise a
RangeError
, and the Regexp
and
String
forms will silently ignore the assignment.
static VALUE rb_str_aset_m(int argc, VALUE *argv, VALUE str) { if (argc == 3) { if (TYPE(argv[0]) == T_REGEXP) { rb_str_subpat_set(str, argv[0], argv[1], argv[2]); } else { rb_str_splice(str, NUM2LONG(argv[0]), NUM2LONG(argv[1]), argv[2]); } return argv[2]; } if (argc != 2) { rb_raise(rb_eArgError, "wrong number of arguments (%d for 2..3)", argc); } return rb_str_aset(str, argv[0], argv[1]); }
Returns true for a string which has only ASCII characters.
"abc".force_encoding("UTF-8").ascii_only? #=> true "abc\u{6666}".force_encoding("UTF-8").ascii_only? #=> false
static VALUE rb_str_is_ascii_only_p(VALUE str) { int cr = rb_enc_str_coderange(str); return cr == ENC_CODERANGE_7BIT ? Qtrue : Qfalse; }
Passes each byte in str to the given block, or returns an enumerator if no block is given.
"hello".each_byte {|c| print c, ' ' }
produces:
104 101 108 108 111
static VALUE rb_str_each_byte(VALUE str) { long i; RETURN_ENUMERATOR(str, 0, 0); for (i=0; i<RSTRING_LEN(str); i++) { rb_yield(INT2FIX(RSTRING_PTR(str)[i] & 0xff)); } return str; }
Returns the length of str in bytes.
static VALUE rb_str_bytesize(VALUE str) { return LONG2NUM(RSTRING_LEN(str)); }
Byte Reference—If passed a single Fixnum
, returns a substring
of one byte at that position. If passed two Fixnum
objects,
returns a substring starting at the offset given by the first, and a length
given by the second. If given a Range
, a substring containing
bytes at offsets given by the range is returned. In all three cases, if an
offset is negative, it is counted from the end of str. Returns
nil
if the initial offset falls outside the string, the length
is negative, or the beginning of the range is greater than the end. The
encoding of the resulted string keeps original encoding.
"hello".byteslice(1) #=> "e" "hello".byteslice(-1) #=> "o" "hello".byteslice(1, 2) #=> "el" "\x80\u3042".byteslice(1, 3) #=> "\u3042" "\x03\u3042\xff".byteslice(1..3) #=> "\u3942"
static VALUE rb_str_byteslice(int argc, VALUE *argv, VALUE str) { if (argc == 2) { return str_byte_substr(str, NUM2LONG(argv[0]), NUM2LONG(argv[1])); } if (argc != 1) { rb_raise(rb_eArgError, "wrong number of arguments (%d for 1..2)", argc); } return str_byte_aref(str, argv[0]); }
Returns a copy of str with the first character converted to uppercase and the remainder to lowercase. Note: case conversion is effective only in ASCII region.
"hello".capitalize #=> "Hello" "HELLO".capitalize #=> "Hello" "123ABC".capitalize #=> "123abc"
static VALUE rb_str_capitalize(VALUE str) { str = rb_str_dup(str); rb_str_capitalize_bang(str); return str; }
Modifies str by converting the first character to uppercase and
the remainder to lowercase. Returns nil
if no changes are
made. Note: case conversion is effective only in ASCII region.
a = "hello" a.capitalize! #=> "Hello" a #=> "Hello" a.capitalize! #=> nil
static VALUE rb_str_capitalize_bang(VALUE str) { rb_encoding *enc; char *s, *send; int modify = 0; unsigned int c; int n; str_modify_keep_cr(str); enc = STR_ENC_GET(str); rb_str_check_dummy_enc(enc); if (RSTRING_LEN(str) == 0 || !RSTRING_PTR(str)) return Qnil; s = RSTRING_PTR(str); send = RSTRING_END(str); c = rb_enc_codepoint_len(s, send, &n, enc); if (rb_enc_islower(c, enc)) { rb_enc_mbcput(rb_enc_toupper(c, enc), s, enc); modify = 1; } s += n; while (s < send) { c = rb_enc_codepoint_len(s, send, &n, enc); if (rb_enc_isupper(c, enc)) { rb_enc_mbcput(rb_enc_tolower(c, enc), s, enc); modify = 1; } s += n; } if (modify) return str; return Qnil; }
Case-insensitive version of String#<=>
.
"abcdef".casecmp("abcde") #=> 1 "aBcDeF".casecmp("abcdef") #=> 0 "abcdef".casecmp("abcdefg") #=> -1 "abcdef".casecmp("ABCDEF") #=> 0
static VALUE rb_str_casecmp(VALUE str1, VALUE str2) { long len; rb_encoding *enc; char *p1, *p1end, *p2, *p2end; StringValue(str2); enc = rb_enc_compatible(str1, str2); if (!enc) { return Qnil; } p1 = RSTRING_PTR(str1); p1end = RSTRING_END(str1); p2 = RSTRING_PTR(str2); p2end = RSTRING_END(str2); if (single_byte_optimizable(str1) && single_byte_optimizable(str2)) { while (p1 < p1end && p2 < p2end) { if (*p1 != *p2) { unsigned int c1 = TOUPPER(*p1 & 0xff); unsigned int c2 = TOUPPER(*p2 & 0xff); if (c1 != c2) return INT2FIX(c1 < c2 ? -1 : 1); } p1++; p2++; } } else { while (p1 < p1end && p2 < p2end) { int l1, c1 = rb_enc_ascget(p1, p1end, &l1, enc); int l2, c2 = rb_enc_ascget(p2, p2end, &l2, enc); if (0 <= c1 && 0 <= c2) { c1 = TOUPPER(c1); c2 = TOUPPER(c2); if (c1 != c2) return INT2FIX(c1 < c2 ? -1 : 1); } else { int r; l1 = rb_enc_mbclen(p1, p1end, enc); l2 = rb_enc_mbclen(p2, p2end, enc); len = l1 < l2 ? l1 : l2; r = memcmp(p1, p2, len); if (r != 0) return INT2FIX(r < 0 ? -1 : 1); if (l1 != l2) return INT2FIX(l1 < l2 ? -1 : 1); } p1 += l1; p2 += l2; } } if (RSTRING_LEN(str1) == RSTRING_LEN(str2)) return INT2FIX(0); if (RSTRING_LEN(str1) > RSTRING_LEN(str2)) return INT2FIX(1); return INT2FIX(-1); }
If integer is greater than the length of str, returns a
new String
of length integer with str
centered and padded with padstr; otherwise, returns str.
"hello".center(4) #=> "hello" "hello".center(20) #=> " hello " "hello".center(20, '123') #=> "1231231hello12312312"
static VALUE rb_str_center(int argc, VALUE *argv, VALUE str) { return rb_str_justify(argc, argv, str, 'c'); }
Passes each character in str to the given block, or returns an enumerator if no block is given.
"hello".each_char {|c| print c, ' ' }
produces:
h e l l o
static VALUE rb_str_each_char(VALUE str) { VALUE orig = str; long i, len, n; const char *ptr; rb_encoding *enc; RETURN_ENUMERATOR(str, 0, 0); str = rb_str_new4(str); ptr = RSTRING_PTR(str); len = RSTRING_LEN(str); enc = rb_enc_get(str); switch (ENC_CODERANGE(str)) { case ENC_CODERANGE_VALID: case ENC_CODERANGE_7BIT: for (i = 0; i < len; i += n) { n = rb_enc_fast_mbclen(ptr + i, ptr + len, enc); rb_yield(rb_str_subseq(str, i, n)); } break; default: for (i = 0; i < len; i += n) { n = rb_enc_mbclen(ptr + i, ptr + len, enc); rb_yield(rb_str_subseq(str, i, n)); } } return orig; }
Returns a new String
with the given record separator removed
from the end of str (if present). If $/
has not been
changed from the default Ruby record separator, then chomp
also removes carriage return characters (that is it will remove
\n
, \r
, and \r\n
).
"hello".chomp #=> "hello" "hello\n".chomp #=> "hello" "hello\r\n".chomp #=> "hello" "hello\n\r".chomp #=> "hello\n" "hello\r".chomp #=> "hello" "hello \n there".chomp #=> "hello \n there" "hello".chomp("llo") #=> "he"
static VALUE rb_str_chomp(int argc, VALUE *argv, VALUE str) { str = rb_str_dup(str); rb_str_chomp_bang(argc, argv, str); return str; }
Modifies str in place as described for String#chomp
,
returning str, or nil
if no modifications were made.
static VALUE rb_str_chomp_bang(int argc, VALUE *argv, VALUE str) { rb_encoding *enc; VALUE rs; int newline; char *p, *pp, *e; long len, rslen; str_modify_keep_cr(str); len = RSTRING_LEN(str); if (len == 0) return Qnil; p = RSTRING_PTR(str); e = p + len; if (argc == 0) { rs = rb_rs; if (rs == rb_default_rs) { smart_chomp: enc = rb_enc_get(str); if (rb_enc_mbminlen(enc) > 1) { pp = rb_enc_left_char_head(p, e-rb_enc_mbminlen(enc), e, enc); if (rb_enc_is_newline(pp, e, enc)) { e = pp; } pp = e - rb_enc_mbminlen(enc); if (pp >= p) { pp = rb_enc_left_char_head(p, pp, e, enc); if (rb_enc_ascget(pp, e, 0, enc) == '\r') { e = pp; } } if (e == RSTRING_END(str)) { return Qnil; } len = e - RSTRING_PTR(str); STR_SET_LEN(str, len); } else { if (RSTRING_PTR(str)[len-1] == '\n') { STR_DEC_LEN(str); if (RSTRING_LEN(str) > 0 && RSTRING_PTR(str)[RSTRING_LEN(str)-1] == '\r') { STR_DEC_LEN(str); } } else if (RSTRING_PTR(str)[len-1] == '\r') { STR_DEC_LEN(str); } else { return Qnil; } } RSTRING_PTR(str)[RSTRING_LEN(str)] = '\0'; return str; } } else { rb_scan_args(argc, argv, "01", &rs); } if (NIL_P(rs)) return Qnil; StringValue(rs); rslen = RSTRING_LEN(rs); if (rslen == 0) { while (len>0 && p[len-1] == '\n') { len--; if (len>0 && p[len-1] == '\r') len--; } if (len < RSTRING_LEN(str)) { STR_SET_LEN(str, len); RSTRING_PTR(str)[len] = '\0'; return str; } return Qnil; } if (rslen > len) return Qnil; newline = RSTRING_PTR(rs)[rslen-1]; if (rslen == 1 && newline == '\n') goto smart_chomp; enc = rb_enc_check(str, rs); if (is_broken_string(rs)) { return Qnil; } pp = e - rslen; if (p[len-1] == newline && (rslen <= 1 || memcmp(RSTRING_PTR(rs), pp, rslen) == 0)) { if (rb_enc_left_char_head(p, pp, e, enc) != pp) return Qnil; if (ENC_CODERANGE(str) != ENC_CODERANGE_7BIT) { ENC_CODERANGE_CLEAR(str); } STR_SET_LEN(str, RSTRING_LEN(str) - rslen); RSTRING_PTR(str)[RSTRING_LEN(str)] = '\0'; return str; } return Qnil; }
Returns a new String
with the last character removed. If the
string ends with \r\n
, both characters are removed. Applying
chop
to an empty string returns an empty string.
String#chomp
is often a safer alternative, as it leaves the
string unchanged if it doesn’t end in a record separator.
"string\r\n".chop #=> "string" "string\n\r".chop #=> "string\n" "string\n".chop #=> "string" "string".chop #=> "strin" "x".chop.chop #=> ""
static VALUE rb_str_chop(VALUE str) { VALUE str2 = rb_str_new5(str, RSTRING_PTR(str), chopped_length(str)); rb_enc_cr_str_copy_for_substr(str2, str); OBJ_INFECT(str2, str); return str2; }
Processes str as for String#chop
, returning
str, or nil
if str is the empty string. See
also String#chomp!
.
static VALUE rb_str_chop_bang(VALUE str) { str_modify_keep_cr(str); if (RSTRING_LEN(str) > 0) { long len; len = chopped_length(str); STR_SET_LEN(str, len); RSTRING_PTR(str)[len] = '\0'; if (ENC_CODERANGE(str) != ENC_CODERANGE_7BIT) { ENC_CODERANGE_CLEAR(str); } return str; } return Qnil; }
Returns a one-character string at the beginning of the string.
a = "abcde" a.chr #=> "a"
static VALUE rb_str_chr(VALUE str) { return rb_str_substr(str, 0, 1); }
Makes string empty.
a = "abcde" a.clear #=> ""
static VALUE rb_str_clear(VALUE str) { str_discard(str); STR_SET_EMBED(str); STR_SET_EMBED_LEN(str, 0); RSTRING_PTR(str)[0] = 0; if (rb_enc_asciicompat(STR_ENC_GET(str))) ENC_CODERANGE_SET(str, ENC_CODERANGE_7BIT); else ENC_CODERANGE_SET(str, ENC_CODERANGE_VALID); return str; }
Passes the Integer
ordinal of each character in str,
also known as a codepoint when applied to Unicode strings to the
given block.
If no block is given, an enumerator is returned instead.
"hello\u0639".each_codepoint {|c| print c, ' ' }
produces:
104 101 108 108 111 1593
static VALUE rb_str_each_codepoint(VALUE str) { VALUE orig = str; int n; unsigned int c; const char *ptr, *end; rb_encoding *enc; if (single_byte_optimizable(str)) return rb_str_each_byte(str); RETURN_ENUMERATOR(str, 0, 0); str = rb_str_new4(str); ptr = RSTRING_PTR(str); end = RSTRING_END(str); enc = STR_ENC_GET(str); while (ptr < end) { c = rb_enc_codepoint_len(ptr, end, &n, enc); rb_yield(UINT2NUM(c)); ptr += n; } return orig; }
Append—Concatenates the given object to str. If the object is a
Integer
, it is considered as a codepoint, and is converted to
a character before concatenation.
a = "hello " a << "world" #=> "hello world" a.concat(33) #=> "hello world!"
VALUE rb_str_concat(VALUE str1, VALUE str2) { unsigned int code; rb_encoding *enc = STR_ENC_GET(str1); if (FIXNUM_P(str2) || TYPE(str2) == T_BIGNUM) { if (rb_num_to_uint(str2, &code) == 0) { } else if (FIXNUM_P(str2)) { rb_raise(rb_eRangeError, "%ld out of char range", FIX2LONG(str2)); } else { rb_raise(rb_eRangeError, "bignum out of char range"); } } else { return rb_str_append(str1, str2); } if (enc == rb_usascii_encoding()) { /* US-ASCII automatically extended to ASCII-8BIT */ char buf[1]; buf[0] = (char)code; if (code > 0xFF) { rb_raise(rb_eRangeError, "%u out of char range", code); } rb_str_cat(str1, buf, 1); if (code > 127) { rb_enc_associate(str1, rb_ascii8bit_encoding()); ENC_CODERANGE_SET(str1, ENC_CODERANGE_VALID); } } else { long pos = RSTRING_LEN(str1); int cr = ENC_CODERANGE(str1); int len; char *buf; switch (len = rb_enc_codelen(code, enc)) { case ONIGERR_INVALID_CODE_POINT_VALUE: rb_raise(rb_eRangeError, "invalid codepoint 0x%X in %s", code, rb_enc_name(enc)); break; case ONIGERR_TOO_BIG_WIDE_CHAR_VALUE: case 0: rb_raise(rb_eRangeError, "%u out of char range", code); break; } buf = ALLOCA_N(char, len + 1); rb_enc_mbcput(code, buf, enc); if (rb_enc_precise_mbclen(buf, buf + len + 1, enc) != len) { rb_raise(rb_eRangeError, "invalid codepoint 0x%X in %s", code, rb_enc_name(enc)); } rb_str_resize(str1, pos+len); strncpy(RSTRING_PTR(str1) + pos, buf, len); if (cr == ENC_CODERANGE_7BIT && code > 127) cr = ENC_CODERANGE_VALID; ENC_CODERANGE_SET(str1, cr); } return str1; }
Each other_str parameter defines a set of characters to count. The intersection of these sets defines the characters to count in str. Any other_str that starts with a caret (^) is negated. The sequence c1–c2 means all characters between c1 and c2.
a = "hello world" a.count "lo" #=> 5 a.count "lo", "o" #=> 2 a.count "hello", "^l" #=> 4 a.count "ej-m" #=> 4
static VALUE rb_str_count(int argc, VALUE *argv, VALUE str) { char table[TR_TABLE_SIZE]; rb_encoding *enc = 0; VALUE del = 0, nodel = 0; char *s, *send; int i; int ascompat; if (argc < 1) { rb_raise(rb_eArgError, "wrong number of arguments (at least 1)"); } for (i=0; i<argc; i++) { VALUE tstr = argv[i]; unsigned char c; StringValue(tstr); enc = rb_enc_check(str, tstr); if (argc == 1 && RSTRING_LEN(tstr) == 1 && rb_enc_asciicompat(enc) && (c = RSTRING_PTR(tstr)[0]) < 0x80 && !is_broken_string(str)) { int n = 0; s = RSTRING_PTR(str); if (!s || RSTRING_LEN(str) == 0) return INT2FIX(0); send = RSTRING_END(str); while (s < send) { if (*(unsigned char*)s++ == c) n++; } return INT2NUM(n); } tr_setup_table(tstr, table, i==0, &del, &nodel, enc); } s = RSTRING_PTR(str); if (!s || RSTRING_LEN(str) == 0) return INT2FIX(0); send = RSTRING_END(str); ascompat = rb_enc_asciicompat(enc); i = 0; while (s < send) { unsigned int c; if (ascompat && (c = *(unsigned char*)s) < 0x80) { if (table[c]) { i++; } s++; } else { int clen; c = rb_enc_codepoint_len(s, send, &clen, enc); if (tr_find(c, table, del, nodel)) { i++; } s += clen; } } return INT2NUM(i); }
Applies a one-way cryptographic hash to str by invoking the
standard library function crypt
. The argument is the salt
string, which should be two characters long, each character drawn from
[a-zA-Z0-9./]
.
static VALUE rb_str_crypt(VALUE str, VALUE salt) { extern char *crypt(const char *, const char *); VALUE result; const char *s, *saltp; char *res; #ifdef BROKEN_CRYPT char salt_8bit_clean[3]; #endif StringValue(salt); if (RSTRING_LEN(salt) < 2) rb_raise(rb_eArgError, "salt too short (need >=2 bytes)"); s = RSTRING_PTR(str); if (!s) s = ""; saltp = RSTRING_PTR(salt); #ifdef BROKEN_CRYPT if (!ISASCII((unsigned char)saltp[0]) || !ISASCII((unsigned char)saltp[1])) { salt_8bit_clean[0] = saltp[0] & 0x7f; salt_8bit_clean[1] = saltp[1] & 0x7f; salt_8bit_clean[2] = '\0'; saltp = salt_8bit_clean; } #endif res = crypt(s, saltp); if (!res) { rb_sys_fail("crypt"); } result = rb_str_new2(res); OBJ_INFECT(result, str); OBJ_INFECT(result, salt); return result; }
Returns a copy of str with all characters in the intersection of
its arguments deleted. Uses the same rules for building the set of
characters as String#count
.
"hello".delete "l","lo" #=> "heo" "hello".delete "lo" #=> "he" "hello".delete "aeiou", "^e" #=> "hell" "hello".delete "ej-m" #=> "ho"
static VALUE rb_str_delete(int argc, VALUE *argv, VALUE str) { str = rb_str_dup(str); rb_str_delete_bang(argc, argv, str); return str; }
Performs a delete
operation in place, returning str,
or nil
if str was not modified.
static VALUE rb_str_delete_bang(int argc, VALUE *argv, VALUE str) { char squeez[TR_TABLE_SIZE]; rb_encoding *enc = 0; char *s, *send, *t; VALUE del = 0, nodel = 0; int modify = 0; int i, ascompat, cr; if (RSTRING_LEN(str) == 0 || !RSTRING_PTR(str)) return Qnil; if (argc < 1) { rb_raise(rb_eArgError, "wrong number of arguments (at least 1)"); } for (i=0; i<argc; i++) { VALUE s = argv[i]; StringValue(s); enc = rb_enc_check(str, s); tr_setup_table(s, squeez, i==0, &del, &nodel, enc); } str_modify_keep_cr(str); ascompat = rb_enc_asciicompat(enc); s = t = RSTRING_PTR(str); send = RSTRING_END(str); cr = ascompat ? ENC_CODERANGE_7BIT : ENC_CODERANGE_VALID; while (s < send) { unsigned int c; int clen; if (ascompat && (c = *(unsigned char*)s) < 0x80) { if (squeez[c]) { modify = 1; } else { if (t != s) *t = c; t++; } s++; } else { c = rb_enc_codepoint_len(s, send, &clen, enc); if (tr_find(c, squeez, del, nodel)) { modify = 1; } else { if (t != s) rb_enc_mbcput(c, t, enc); t += clen; if (cr == ENC_CODERANGE_7BIT) cr = ENC_CODERANGE_VALID; } s += clen; } } *t = '\0'; STR_SET_LEN(str, t - RSTRING_PTR(str)); ENC_CODERANGE_SET(str, cr); if (modify) return str; return Qnil; }
Returns a copy of str with all uppercase letters replaced with their lowercase counterparts. The operation is locale insensitive—only characters “A” to “Z” are affected. Note: case replacement is effective only in ASCII region.
"hEllO".downcase #=> "hello"
static VALUE rb_str_downcase(VALUE str) { str = rb_str_dup(str); rb_str_downcase_bang(str); return str; }
Downcases the contents of str, returning nil
if no
changes were made. Note: case replacement is effective only in ASCII
region.
static VALUE rb_str_downcase_bang(VALUE str) { rb_encoding *enc; char *s, *send; int modify = 0; str_modify_keep_cr(str); enc = STR_ENC_GET(str); rb_str_check_dummy_enc(enc); s = RSTRING_PTR(str); send = RSTRING_END(str); if (single_byte_optimizable(str)) { while (s < send) { unsigned int c = *(unsigned char*)s; if (rb_enc_isascii(c, enc) && 'A' <= c && c <= 'Z') { *s = 'a' + (c - 'A'); modify = 1; } s++; } } else { int ascompat = rb_enc_asciicompat(enc); while (s < send) { unsigned int c; int n; if (ascompat && (c = *(unsigned char*)s) < 0x80) { if (rb_enc_isascii(c, enc) && 'A' <= c && c <= 'Z') { *s = 'a' + (c - 'A'); modify = 1; } s++; } else { c = rb_enc_codepoint_len(s, send, &n, enc); if (rb_enc_isupper(c, enc)) { /* assuming toupper returns codepoint with same size */ rb_enc_mbcput(rb_enc_tolower(c, enc), s, enc); modify = 1; } s += n; } } } if (modify) return str; return Qnil; }
Produces a version of str with all nonprinting characters replaced
by \nnn
notation and all special characters escaped.
VALUE rb_str_dump(VALUE str) { rb_encoding *enc = rb_enc_get(str); long len; const char *p, *pend; char *q, *qend; VALUE result; int u8 = (enc == rb_utf8_encoding()); len = 2; /* "" */ p = RSTRING_PTR(str); pend = p + RSTRING_LEN(str); while (p < pend) { unsigned char c = *p++; switch (c) { case '"': case '\\': case '\n': case '\r': case '\t': case '\f': case '\013': case '\010': case '\007': case '\033': len += 2; break; case '#': len += IS_EVSTR(p, pend) ? 2 : 1; break; default: if (ISPRINT(c)) { len++; } else { if (u8) { /* \u{NN} */ int n = rb_enc_precise_mbclen(p-1, pend, enc); if (MBCLEN_CHARFOUND_P(n-1)) { unsigned int cc = rb_enc_mbc_to_codepoint(p-1, pend, enc); while (cc >>= 4) len++; len += 5; p += MBCLEN_CHARFOUND_LEN(n)-1; break; } } len += 4; /* \xNN */ } break; } } if (!rb_enc_asciicompat(enc)) { len += 19; /* ".force_encoding('')" */ len += strlen(enc->name); } result = rb_str_new5(str, 0, len); p = RSTRING_PTR(str); pend = p + RSTRING_LEN(str); q = RSTRING_PTR(result); qend = q + len + 1; *q++ = '"'; while (p < pend) { unsigned char c = *p++; if (c == '"' || c == '\\') { *q++ = '\\'; *q++ = c; } else if (c == '#') { if (IS_EVSTR(p, pend)) *q++ = '\\'; *q++ = '#'; } else if (c == '\n') { *q++ = '\\'; *q++ = 'n'; } else if (c == '\r') { *q++ = '\\'; *q++ = 'r'; } else if (c == '\t') { *q++ = '\\'; *q++ = 't'; } else if (c == '\f') { *q++ = '\\'; *q++ = 'f'; } else if (c == '\013') { *q++ = '\\'; *q++ = 'v'; } else if (c == '\010') { *q++ = '\\'; *q++ = 'b'; } else if (c == '\007') { *q++ = '\\'; *q++ = 'a'; } else if (c == '\033') { *q++ = '\\'; *q++ = 'e'; } else if (ISPRINT(c)) { *q++ = c; } else { *q++ = '\\'; if (u8) { int n = rb_enc_precise_mbclen(p-1, pend, enc) - 1; if (MBCLEN_CHARFOUND_P(n)) { int cc = rb_enc_mbc_to_codepoint(p-1, pend, enc); p += n; snprintf(q, qend-q, "u{%x}", cc); q += strlen(q); continue; } } snprintf(q, qend-q, "x%02X", c); q += 3; } } *q++ = '"'; *q = '\0'; if (!rb_enc_asciicompat(enc)) { snprintf(q, qend-q, ".force_encoding(\"%s\")", enc->name); enc = rb_ascii8bit_encoding(); } OBJ_INFECT(result, str); /* result from dump is ASCII */ rb_enc_associate(result, enc); ENC_CODERANGE_SET(result, ENC_CODERANGE_7BIT); return result; }
Passes each byte in str to the given block, or returns an enumerator if no block is given.
"hello".each_byte {|c| print c, ' ' }
produces:
104 101 108 108 111
static VALUE rb_str_each_byte(VALUE str) { long i; RETURN_ENUMERATOR(str, 0, 0); for (i=0; i<RSTRING_LEN(str); i++) { rb_yield(INT2FIX(RSTRING_PTR(str)[i] & 0xff)); } return str; }
Passes each character in str to the given block, or returns an enumerator if no block is given.
"hello".each_char {|c| print c, ' ' }
produces:
h e l l o
static VALUE rb_str_each_char(VALUE str) { VALUE orig = str; long i, len, n; const char *ptr; rb_encoding *enc; RETURN_ENUMERATOR(str, 0, 0); str = rb_str_new4(str); ptr = RSTRING_PTR(str); len = RSTRING_LEN(str); enc = rb_enc_get(str); switch (ENC_CODERANGE(str)) { case ENC_CODERANGE_VALID: case ENC_CODERANGE_7BIT: for (i = 0; i < len; i += n) { n = rb_enc_fast_mbclen(ptr + i, ptr + len, enc); rb_yield(rb_str_subseq(str, i, n)); } break; default: for (i = 0; i < len; i += n) { n = rb_enc_mbclen(ptr + i, ptr + len, enc); rb_yield(rb_str_subseq(str, i, n)); } } return orig; }
Passes the Integer
ordinal of each character in str,
also known as a codepoint when applied to Unicode strings to the
given block.
If no block is given, an enumerator is returned instead.
"hello\u0639".each_codepoint {|c| print c, ' ' }
produces:
104 101 108 108 111 1593
static VALUE rb_str_each_codepoint(VALUE str) { VALUE orig = str; int n; unsigned int c; const char *ptr, *end; rb_encoding *enc; if (single_byte_optimizable(str)) return rb_str_each_byte(str); RETURN_ENUMERATOR(str, 0, 0); str = rb_str_new4(str); ptr = RSTRING_PTR(str); end = RSTRING_END(str); enc = STR_ENC_GET(str); while (ptr < end) { c = rb_enc_codepoint_len(ptr, end, &n, enc); rb_yield(UINT2NUM(c)); ptr += n; } return orig; }
Splits str using the supplied parameter as the record separator
($/
by default), passing each substring in turn to the
supplied block. If a zero-length record separator is supplied, the string
is split into paragraphs delimited by multiple successive newlines.
If no block is given, an enumerator is returned instead.
print "Example one\n" "hello\nworld".each_line {|s| p s} print "Example two\n" "hello\nworld".each_line('l') {|s| p s} print "Example three\n" "hello\n\n\nworld".each_line('') {|s| p s}
produces:
Example one "hello\n" "world" Example two "hel" "l" "o\nworl" "d" Example three "hello\n\n\n" "world"
static VALUE rb_str_each_line(int argc, VALUE *argv, VALUE str) { rb_encoding *enc; VALUE rs; unsigned int newline; const char *p, *pend, *s, *ptr; long len, rslen; VALUE line; int n; VALUE orig = str; if (argc == 0) { rs = rb_rs; } else { rb_scan_args(argc, argv, "01", &rs); } RETURN_ENUMERATOR(str, argc, argv); if (NIL_P(rs)) { rb_yield(str); return orig; } str = rb_str_new4(str); ptr = p = s = RSTRING_PTR(str); pend = p + RSTRING_LEN(str); len = RSTRING_LEN(str); StringValue(rs); if (rs == rb_default_rs) { enc = rb_enc_get(str); while (p < pend) { char *p0; p = memchr(p, '\n', pend - p); if (!p) break; p0 = rb_enc_left_char_head(s, p, pend, enc); if (!rb_enc_is_newline(p0, pend, enc)) { p++; continue; } p = p0 + rb_enc_mbclen(p0, pend, enc); line = rb_str_new5(str, s, p - s); OBJ_INFECT(line, str); rb_enc_cr_str_copy_for_substr(line, str); rb_yield(line); str_mod_check(str, ptr, len); s = p; } goto finish; } enc = rb_enc_check(str, rs); rslen = RSTRING_LEN(rs); if (rslen == 0) { newline = '\n'; } else { newline = rb_enc_codepoint(RSTRING_PTR(rs), RSTRING_END(rs), enc); } while (p < pend) { unsigned int c = rb_enc_codepoint_len(p, pend, &n, enc); again: if (rslen == 0 && c == newline) { p += n; if (p < pend && (c = rb_enc_codepoint_len(p, pend, &n, enc)) != newline) { goto again; } while (p < pend && rb_enc_codepoint(p, pend, enc) == newline) { p += n; } p -= n; } if (c == newline && (rslen <= 1 || (pend - p >= rslen && memcmp(RSTRING_PTR(rs), p, rslen) == 0))) { line = rb_str_new5(str, s, p - s + (rslen ? rslen : n)); OBJ_INFECT(line, str); rb_enc_cr_str_copy_for_substr(line, str); rb_yield(line); str_mod_check(str, ptr, len); s = p + (rslen ? rslen : n); } p += n; } finish: if (s != pend) { line = rb_str_new5(str, s, pend - s); OBJ_INFECT(line, str); rb_enc_cr_str_copy_for_substr(line, str); rb_yield(line); } return orig; }
Returns true
if str has a length of zero.
"hello".empty? #=> false "".empty? #=> true
static VALUE rb_str_empty(VALUE str) { if (RSTRING_LEN(str) == 0) return Qtrue; return Qfalse; }
The first form returns a copy of str
transcoded to encoding
encoding
. The second form returns a copy of str
transcoded from src_encoding to dst_encoding. The last form returns a copy
of str
transcoded to Encoding.default_internal
.
By default, the first and second form raise Encoding::UndefinedConversionError for characters that are undefined in the destination encoding, and Encoding::InvalidByteSequenceError for invalid byte sequences in the source encoding. The last form by default does not raise exceptions but uses replacement strings.
Please note that conversion from an encoding enc
to the same
encoding enc
is a no-op, i.e. the receiver is returned without
any changes, and no exceptions are raised, even if there are invalid bytes.
The options
Hash gives details for
conversion and can have the following keys:
If the value is :replace
, encode replaces invalid byte
sequences in str
with the replacement character. The default
is to raise the Encoding::InvalidByteSequenceError
exception
If the value is :replace
, encode replaces characters which are
undefined in the destination encoding with the replacement character. The
default is to raise the Encoding::UndefinedConversionError.
Sets the replacement string to the given value. The default replacement string is “uFFFD” for Unicode encoding forms, and “?” otherwise.
Sets the replacement string by the given object for undefined character. The object should be a Hash, a Proc, a Method, or an object which has [] method. Its key is an undefined character encoded in the source encoding of current transcoder. Its value can be any encoding until it can be converted into the destination encoding of the transcoder.
The value must be :text
or :attr
. If the value is
:text
encode
replaces undefined characters with their (upper-case hexadecimal) numeric
character references. ‘&’, ‘<’, and ‘>’ are converted to
“&”, “<”, and “>”, respectively. If the value is
:attr
, encode also
quotes the replacement result (using ‘“’), and replaces ‘”’ with
“"”.
Replaces LF (“n”) with CR (“r”) if value is true.
Replaces LF (“n”) with CRLF (“rn”) if value is true.
Replaces CRLF (“rn”) and CR (“r”) with LF (“n”) if value is true.
static VALUE str_encode(int argc, VALUE *argv, VALUE str) { VALUE newstr = str; int encidx = str_transcode(argc, argv, &newstr); return encoded_dup(newstr, str, encidx); }
The first form transcodes the contents of str from str.encoding to
encoding
. The second form transcodes the contents of
str from src_encoding to dst_encoding. The options Hash gives details for conversion. See #encode for details. Returns the
string even if no changes were made.
static VALUE str_encode_bang(int argc, VALUE *argv, VALUE str) { VALUE newstr; int encidx; rb_check_frozen(str); newstr = str; encidx = str_transcode(argc, argv, &newstr); if (encidx < 0) return str; if (newstr == str) { rb_enc_associate_index(str, encidx); return str; } rb_str_shared_replace(str, newstr); return str_encode_associate(str, encidx); }
Returns the Encoding object that represents the encoding of obj.
VALUE rb_obj_encoding(VALUE obj) { rb_encoding *enc = rb_enc_get(obj); if (!enc) { rb_raise(rb_eTypeError, "unknown encoding"); } return rb_enc_from_encoding(enc); }
Returns true if str ends with one of the suffixes given.
static VALUE rb_str_end_with(int argc, VALUE *argv, VALUE str) { int i; char *p, *s, *e; rb_encoding *enc; for (i=0; i<argc; i++) { VALUE tmp = rb_check_string_type(argv[i]); if (NIL_P(tmp)) continue; enc = rb_enc_check(str, tmp); if (RSTRING_LEN(str) < RSTRING_LEN(tmp)) continue; p = RSTRING_PTR(str); e = p + RSTRING_LEN(str); s = e - RSTRING_LEN(tmp); if (rb_enc_left_char_head(p, s, e, enc) != s) continue; if (memcmp(s, RSTRING_PTR(tmp), RSTRING_LEN(tmp)) == 0) return Qtrue; } return Qfalse; }
Two strings are equal if they have the same length and content.
static VALUE rb_str_eql(VALUE str1, VALUE str2) { if (str1 == str2) return Qtrue; if (TYPE(str2) != T_STRING) return Qfalse; return str_eql(str1, str2); }
Changes the encoding to encoding
and returns self.
static VALUE rb_str_force_encoding(VALUE str, VALUE enc) { str_modifiable(str); rb_enc_associate(str, rb_to_encoding(enc)); ENC_CODERANGE_CLEAR(str); return str; }
returns the indexth byte as an integer.
static VALUE rb_str_getbyte(VALUE str, VALUE index) { long pos = NUM2LONG(index); if (pos < 0) pos += RSTRING_LEN(str); if (pos < 0 || RSTRING_LEN(str) <= pos) return Qnil; return INT2FIX((unsigned char)RSTRING_PTR(str)[pos]); }
Returns a copy of str with the all occurrences of
pattern substituted for the second argument. The pattern
is typically a Regexp
; if given as a String
, any
regular expression metacharacters it contains will be interpreted
literally, e.g. '\\d'
will match a backlash followed by ‘d’,
instead of a digit.
If replacement is a String
it will be substituted for
the matched text. It may contain back-references to the pattern’s capture
groups of the form \\d
, where d is a group number, or
\\k<n>
, where n is a group name. If it is a
double-quoted string, both back-references must be preceded by an
additional backslash. However, within replacement the special
match variables, such as &$
, will not refer to the current
match.
If the second argument is a Hash
, and the matched text is one
of its keys, the corresponding value is the replacement string.
In the block form, the current match string is passed in as a parameter,
and variables such as $1
, $2
, $`
,
$&
, and $'
will be set appropriately. The
value returned by the block will be substituted for the match on each call.
The result inherits any tainting in the original string or any supplied replacement string.
When neither a block nor a second argument is supplied, an
Enumerator
is returned.
"hello".gsub(/[aeiou]/, '*') #=> "h*ll*" "hello".gsub(/([aeiou])/, '<\1>') #=> "h<e>ll<o>" "hello".gsub(/./) {|s| s.ord.to_s + ' '} #=> "104 101 108 108 111 " "hello".gsub(/(?<foo>[aeiou])/, '{\k<foo>}') #=> "h{e}ll{o}" 'hello'.gsub(/[eo]/, 'e' => 3, 'o' => '*') #=> "h3ll*"
static VALUE rb_str_gsub(int argc, VALUE *argv, VALUE str) { return str_gsub(argc, argv, str, 0); }
Performs the substitutions of String#gsub
in place, returning
str, or nil
if no substitutions were performed. If no
block and no replacement is given, an enumerator is returned
instead.
static VALUE rb_str_gsub_bang(int argc, VALUE *argv, VALUE str) { str_modify_keep_cr(str); return str_gsub(argc, argv, str, 1); }
Return a hash based on the string’s length and content.
static VALUE rb_str_hash_m(VALUE str) { st_index_t hval = rb_str_hash(str); return INT2FIX(hval); }
Treats leading characters from str as a string of hexadecimal
digits (with an optional sign and an optional 0x
) and returns
the corresponding number. Zero is returned on error.
"0x0a".hex #=> 10 "-1234".hex #=> -4660 "0".hex #=> 0 "wombat".hex #=> 0
static VALUE rb_str_hex(VALUE str) { rb_encoding *enc = rb_enc_get(str); if (!rb_enc_asciicompat(enc)) { rb_raise(rb_eEncCompatError, "ASCII incompatible encoding: %s", rb_enc_name(enc)); } return rb_str_to_inum(str, 16, FALSE); }
Returns true
if str contains the given string or
character.
"hello".include? "lo" #=> true "hello".include? "ol" #=> false "hello".include? ?h #=> true
static VALUE rb_str_include(VALUE str, VALUE arg) { long i; StringValue(arg); i = rb_str_index(str, arg, 0); if (i == -1) return Qfalse; return Qtrue; }
Returns the index of the first occurrence of the given substring
or pattern (regexp) in str. Returns nil
if
not found. If the second parameter is present, it specifies the position in
the string to begin the search.
"hello".index('e') #=> 1 "hello".index('lo') #=> 3 "hello".index('a') #=> nil "hello".index(?e) #=> 1 "hello".index(/[aeiou]/, -3) #=> 4
static VALUE rb_str_index_m(int argc, VALUE *argv, VALUE str) { VALUE sub; VALUE initpos; long pos; if (rb_scan_args(argc, argv, "11", &sub, &initpos) == 2) { pos = NUM2LONG(initpos); } else { pos = 0; } if (pos < 0) { pos += str_strlen(str, STR_ENC_GET(str)); if (pos < 0) { if (TYPE(sub) == T_REGEXP) { rb_backref_set(Qnil); } return Qnil; } } switch (TYPE(sub)) { case T_REGEXP: if (pos > str_strlen(str, STR_ENC_GET(str))) return Qnil; pos = str_offset(RSTRING_PTR(str), RSTRING_END(str), pos, rb_enc_check(str, sub), single_byte_optimizable(str)); pos = rb_reg_search(sub, str, pos, 0); pos = rb_str_sublen(str, pos); break; default: { VALUE tmp; tmp = rb_check_string_type(sub); if (NIL_P(tmp)) { rb_raise(rb_eTypeError, "type mismatch: %s given", rb_obj_classname(sub)); } sub = tmp; } /* fall through */ case T_STRING: pos = rb_str_index(str, sub, pos); pos = rb_str_sublen(str, pos); break; } if (pos == -1) return Qnil; return LONG2NUM(pos); }
Replaces the contents and taintedness of str with the corresponding values in other_str.
s = "hello" #=> "hello" s.replace "world" #=> "world"
VALUE rb_str_replace(VALUE str, VALUE str2) { str_modifiable(str); if (str == str2) return str; StringValue(str2); str_discard(str); return str_replace(str, str2); }
Inserts other_str before the character at the given index, modifying str. Negative indices count from the end of the string, and insert after the given character. The intent is insert aString so that it starts at the given index.
"abcd".insert(0, 'X') #=> "Xabcd" "abcd".insert(3, 'X') #=> "abcXd" "abcd".insert(4, 'X') #=> "abcdX" "abcd".insert(-3, 'X') #=> "abXcd" "abcd".insert(-1, 'X') #=> "abcdX"
static VALUE rb_str_insert(VALUE str, VALUE idx, VALUE str2) { long pos = NUM2LONG(idx); if (pos == -1) { return rb_str_append(str, str2); } else if (pos < 0) { pos++; } rb_str_splice(str, pos, 0, str2); return str; }
Returns a printable version of str, surrounded by quote marks, with special characters escaped.
str = "hello" str[3] = "\b" str.inspect #=> "\"hel\\bo\""
VALUE rb_str_inspect(VALUE str) { rb_encoding *enc = STR_ENC_GET(str); const char *p, *pend, *prev; char buf[CHAR_ESC_LEN + 1]; VALUE result = rb_str_buf_new(0); rb_encoding *resenc = rb_default_internal_encoding(); int unicode_p = rb_enc_unicode_p(enc); int asciicompat = rb_enc_asciicompat(enc); static rb_encoding *utf16, *utf32; if (!utf16) utf16 = rb_enc_find("UTF-16"); if (!utf32) utf32 = rb_enc_find("UTF-32"); if (resenc == NULL) resenc = rb_default_external_encoding(); if (!rb_enc_asciicompat(resenc)) resenc = rb_usascii_encoding(); rb_enc_associate(result, resenc); str_buf_cat2(result, "\""); p = RSTRING_PTR(str); pend = RSTRING_END(str); prev = p; if (enc == utf16) { const unsigned char *q = (const unsigned char *)p; if (q[0] == 0xFE && q[1] == 0xFF) enc = rb_enc_find("UTF-16BE"); else if (q[0] == 0xFF && q[1] == 0xFE) enc = rb_enc_find("UTF-16LE"); else unicode_p = 0; } else if (enc == utf32) { const unsigned char *q = (const unsigned char *)p; if (q[0] == 0 && q[1] == 0 && q[2] == 0xFE && q[3] == 0xFF) enc = rb_enc_find("UTF-32BE"); else if (q[3] == 0 && q[2] == 0 && q[1] == 0xFE && q[0] == 0xFF) enc = rb_enc_find("UTF-32LE"); else unicode_p = 0; } while (p < pend) { unsigned int c, cc; int n; n = rb_enc_precise_mbclen(p, pend, enc); if (!MBCLEN_CHARFOUND_P(n)) { if (p > prev) str_buf_cat(result, prev, p - prev); n = rb_enc_mbminlen(enc); if (pend < p + n) n = (int)(pend - p); while (n--) { snprintf(buf, CHAR_ESC_LEN, "\\x%02X", *p & 0377); str_buf_cat(result, buf, strlen(buf)); prev = ++p; } continue; } n = MBCLEN_CHARFOUND_LEN(n); c = rb_enc_mbc_to_codepoint(p, pend, enc); p += n; if ((asciicompat || unicode_p) && (c == '"'|| c == '\\' || (c == '#' && p < pend && MBCLEN_CHARFOUND_P(rb_enc_precise_mbclen(p,pend,enc)) && (cc = rb_enc_codepoint(p,pend,enc), (cc == '$' || cc == '@' || cc == '{'))))) { if (p - n > prev) str_buf_cat(result, prev, p - n - prev); str_buf_cat2(result, "\\"); if (asciicompat || enc == resenc) { prev = p - n; continue; } } switch (c) { case '\n': cc = 'n'; break; case '\r': cc = 'r'; break; case '\t': cc = 't'; break; case '\f': cc = 'f'; break; case '\013': cc = 'v'; break; case '\010': cc = 'b'; break; case '\007': cc = 'a'; break; case 033: cc = 'e'; break; default: cc = 0; break; } if (cc) { if (p - n > prev) str_buf_cat(result, prev, p - n - prev); buf[0] = '\\'; buf[1] = (char)cc; str_buf_cat(result, buf, 2); prev = p; continue; } if ((enc == resenc && rb_enc_isprint(c, enc)) || (asciicompat && rb_enc_isascii(c, enc) && ISPRINT(c))) { continue; } else { if (p - n > prev) str_buf_cat(result, prev, p - n - prev); rb_str_buf_cat_escaped_char(result, c, unicode_p); prev = p; continue; } } if (p > prev) str_buf_cat(result, prev, p - prev); str_buf_cat2(result, "\""); OBJ_INFECT(result, str); return result; }
Returns the Symbol
corresponding to str, creating the
symbol if it did not previously exist. See Symbol#id2name
.
"Koala".intern #=> :Koala s = 'cat'.to_sym #=> :cat s == :cat #=> true s = '@cat'.to_sym #=> :@cat s == :@cat #=> true
This can also be used to create symbols that cannot be represented using
the :xxx
notation.
'cat and dog'.to_sym #=> :"cat and dog"
VALUE rb_str_intern(VALUE s) { VALUE str = RB_GC_GUARD(s); ID id; id = rb_intern_str(str); return ID2SYM(id); }
Returns the character length of str.
VALUE rb_str_length(VALUE str) { long len; len = str_strlen(str, STR_ENC_GET(str)); return LONG2NUM(len); }
Splits str using the supplied parameter as the record separator
($/
by default), passing each substring in turn to the
supplied block. If a zero-length record separator is supplied, the string
is split into paragraphs delimited by multiple successive newlines.
If no block is given, an enumerator is returned instead.
print "Example one\n" "hello\nworld".each_line {|s| p s} print "Example two\n" "hello\nworld".each_line('l') {|s| p s} print "Example three\n" "hello\n\n\nworld".each_line('') {|s| p s}
produces:
Example one "hello\n" "world" Example two "hel" "l" "o\nworl" "d" Example three "hello\n\n\n" "world"
static VALUE rb_str_each_line(int argc, VALUE *argv, VALUE str) { rb_encoding *enc; VALUE rs; unsigned int newline; const char *p, *pend, *s, *ptr; long len, rslen; VALUE line; int n; VALUE orig = str; if (argc == 0) { rs = rb_rs; } else { rb_scan_args(argc, argv, "01", &rs); } RETURN_ENUMERATOR(str, argc, argv); if (NIL_P(rs)) { rb_yield(str); return orig; } str = rb_str_new4(str); ptr = p = s = RSTRING_PTR(str); pend = p + RSTRING_LEN(str); len = RSTRING_LEN(str); StringValue(rs); if (rs == rb_default_rs) { enc = rb_enc_get(str); while (p < pend) { char *p0; p = memchr(p, '\n', pend - p); if (!p) break; p0 = rb_enc_left_char_head(s, p, pend, enc); if (!rb_enc_is_newline(p0, pend, enc)) { p++; continue; } p = p0 + rb_enc_mbclen(p0, pend, enc); line = rb_str_new5(str, s, p - s); OBJ_INFECT(line, str); rb_enc_cr_str_copy_for_substr(line, str); rb_yield(line); str_mod_check(str, ptr, len); s = p; } goto finish; } enc = rb_enc_check(str, rs); rslen = RSTRING_LEN(rs); if (rslen == 0) { newline = '\n'; } else { newline = rb_enc_codepoint(RSTRING_PTR(rs), RSTRING_END(rs), enc); } while (p < pend) { unsigned int c = rb_enc_codepoint_len(p, pend, &n, enc); again: if (rslen == 0 && c == newline) { p += n; if (p < pend && (c = rb_enc_codepoint_len(p, pend, &n, enc)) != newline) { goto again; } while (p < pend && rb_enc_codepoint(p, pend, enc) == newline) { p += n; } p -= n; } if (c == newline && (rslen <= 1 || (pend - p >= rslen && memcmp(RSTRING_PTR(rs), p, rslen) == 0))) { line = rb_str_new5(str, s, p - s + (rslen ? rslen : n)); OBJ_INFECT(line, str); rb_enc_cr_str_copy_for_substr(line, str); rb_yield(line); str_mod_check(str, ptr, len); s = p + (rslen ? rslen : n); } p += n; } finish: if (s != pend) { line = rb_str_new5(str, s, pend - s); OBJ_INFECT(line, str); rb_enc_cr_str_copy_for_substr(line, str); rb_yield(line); } return orig; }
If integer is greater than the length of str, returns a
new String
of length integer with str left
justified and padded with padstr; otherwise, returns str.
"hello".ljust(4) #=> "hello" "hello".ljust(20) #=> "hello " "hello".ljust(20, '1234') #=> "hello123412341234123"
static VALUE rb_str_ljust(int argc, VALUE *argv, VALUE str) { return rb_str_justify(argc, argv, str, 'l'); }
Returns a copy of str with leading whitespace removed. See also
String#rstrip
and String#strip
.
" hello ".lstrip #=> "hello " "hello".lstrip #=> "hello"
static VALUE rb_str_lstrip(VALUE str) { str = rb_str_dup(str); rb_str_lstrip_bang(str); return str; }
Removes leading whitespace from str, returning nil
if
no change was made. See also String#rstrip!
and
String#strip!
.
" hello ".lstrip #=> "hello " "hello".lstrip! #=> nil
static VALUE rb_str_lstrip_bang(VALUE str) { rb_encoding *enc; char *s, *t, *e; str_modify_keep_cr(str); enc = STR_ENC_GET(str); s = RSTRING_PTR(str); if (!s || RSTRING_LEN(str) == 0) return Qnil; e = t = RSTRING_END(str); /* remove spaces at head */ while (s < e) { int n; unsigned int cc = rb_enc_codepoint_len(s, e, &n, enc); if (!rb_isspace(cc)) break; s += n; } if (s > RSTRING_PTR(str)) { STR_SET_LEN(str, t-s); memmove(RSTRING_PTR(str), s, RSTRING_LEN(str)); RSTRING_PTR(str)[RSTRING_LEN(str)] = '\0'; return str; } return Qnil; }
Converts pattern to a Regexp
(if it isn’t already
one), then invokes its match
method on str. If the
second parameter is present, it specifies the position in the string to
begin the search.
'hello'.match('(.)\1') #=> #<MatchData "ll" 1:"l"> 'hello'.match('(.)\1')[0] #=> "ll" 'hello'.match(/(.)\1/)[0] #=> "ll" 'hello'.match('xx') #=> nil
If a block is given, invoke the block with MatchData if match succeed, so that you can write
str.match(pat) {|m| ...}
instead of
if m = str.match(pat) ... end
The return value is a value from block execution in this case.
static VALUE rb_str_match_m(int argc, VALUE *argv, VALUE str) { VALUE re, result; if (argc < 1) rb_raise(rb_eArgError, "wrong number of arguments (%d for 1..2)", argc); re = argv[0]; argv[0] = str; result = rb_funcall2(get_pat(re, 0), rb_intern("match"), argc, argv); if (!NIL_P(result) && rb_block_given_p()) { return rb_yield(result); } return result; }
Returns the successor to str. The successor is calculated by incrementing characters starting from the rightmost alphanumeric (or the rightmost character if there are no alphanumerics) in the string. Incrementing a digit always results in another digit, and incrementing a letter results in another letter of the same case. Incrementing nonalphanumerics uses the underlying character set’s collating sequence.
If the increment generates a “carry,” the character to the left of it is incremented. This process repeats until there is no carry, adding an additional character if necessary.
"abcd".succ #=> "abce" "THX1138".succ #=> "THX1139" "<<koala>>".succ #=> "<<koalb>>" "1999zzz".succ #=> "2000aaa" "ZZZ9999".succ #=> "AAAA0000" "***".succ #=> "**+"
VALUE rb_str_succ(VALUE orig) { rb_encoding *enc; VALUE str; char *sbeg, *s, *e, *last_alnum = 0; int c = -1; long l; char carry[ONIGENC_CODE_TO_MBC_MAXLEN] = "\1"; long carry_pos = 0, carry_len = 1; enum neighbor_char neighbor = NEIGHBOR_FOUND; str = rb_str_new5(orig, RSTRING_PTR(orig), RSTRING_LEN(orig)); rb_enc_cr_str_copy_for_substr(str, orig); OBJ_INFECT(str, orig); if (RSTRING_LEN(str) == 0) return str; enc = STR_ENC_GET(orig); sbeg = RSTRING_PTR(str); s = e = sbeg + RSTRING_LEN(str); while ((s = rb_enc_prev_char(sbeg, s, e, enc)) != 0) { if (neighbor == NEIGHBOR_NOT_CHAR && last_alnum) { if (ISALPHA(*last_alnum) ? ISDIGIT(*s) : ISDIGIT(*last_alnum) ? ISALPHA(*s) : 0) { s = last_alnum; break; } } if ((l = rb_enc_precise_mbclen(s, e, enc)) <= 0) continue; neighbor = enc_succ_alnum_char(s, l, enc, carry); switch (neighbor) { case NEIGHBOR_NOT_CHAR: continue; case NEIGHBOR_FOUND: return str; case NEIGHBOR_WRAPPED: last_alnum = s; break; } c = 1; carry_pos = s - sbeg; carry_len = l; } if (c == -1) { /* str contains no alnum */ s = e; while ((s = rb_enc_prev_char(sbeg, s, e, enc)) != 0) { enum neighbor_char neighbor; if ((l = rb_enc_precise_mbclen(s, e, enc)) <= 0) continue; neighbor = enc_succ_char(s, l, enc); if (neighbor == NEIGHBOR_FOUND) return str; if (rb_enc_precise_mbclen(s, s+l, enc) != l) { /* wrapped to \0...\0. search next valid char. */ enc_succ_char(s, l, enc); } if (!rb_enc_asciicompat(enc)) { MEMCPY(carry, s, char, l); carry_len = l; } carry_pos = s - sbeg; } } RESIZE_CAPA(str, RSTRING_LEN(str) + carry_len); s = RSTRING_PTR(str) + carry_pos; memmove(s + carry_len, s, RSTRING_LEN(str) - carry_pos); memmove(s, carry, carry_len); STR_SET_LEN(str, RSTRING_LEN(str) + carry_len); RSTRING_PTR(str)[RSTRING_LEN(str)] = '\0'; rb_enc_str_coderange(str); return str; }
Equivalent to String#succ
, but modifies the receiver in place.
static VALUE rb_str_succ_bang(VALUE str) { rb_str_shared_replace(str, rb_str_succ(str)); return str; }
Treats leading characters of str as a string of octal digits (with an optional sign) and returns the corresponding number. Returns 0 if the conversion fails.
"123".oct #=> 83 "-377".oct #=> -255 "bad".oct #=> 0 "0377bad".oct #=> 255
static VALUE rb_str_oct(VALUE str) { rb_encoding *enc = rb_enc_get(str); if (!rb_enc_asciicompat(enc)) { rb_raise(rb_eEncCompatError, "ASCII incompatible encoding: %s", rb_enc_name(enc)); } return rb_str_to_inum(str, -8, FALSE); }
Return the Integer
ordinal of a one-character string.
"a".ord #=> 97
VALUE rb_str_ord(VALUE s) { unsigned int c; c = rb_enc_codepoint(RSTRING_PTR(s), RSTRING_END(s), STR_ENC_GET(s)); return UINT2NUM(c); }
Searches sep or pattern (regexp) in the string and returns the part before it, the match, and the part after it. If it is not found, returns two empty strings and str.
"hello".partition("l") #=> ["he", "l", "lo"] "hello".partition("x") #=> ["hello", "", ""] "hello".partition(/.l/) #=> ["h", "el", "lo"]
static VALUE rb_str_partition(VALUE str, VALUE sep) { long pos; int regex = FALSE; if (TYPE(sep) == T_REGEXP) { pos = rb_reg_search(sep, str, 0, 0); regex = TRUE; } else { VALUE tmp; tmp = rb_check_string_type(sep); if (NIL_P(tmp)) { rb_raise(rb_eTypeError, "type mismatch: %s given", rb_obj_classname(sep)); } sep = tmp; pos = rb_str_index(str, sep, 0); } if (pos < 0) { failed: return rb_ary_new3(3, str, str_new_empty(str), str_new_empty(str)); } if (regex) { sep = rb_str_subpat(str, sep, INT2FIX(0)); if (pos == 0 && RSTRING_LEN(sep) == 0) goto failed; } return rb_ary_new3(3, rb_str_subseq(str, 0, pos), sep, rb_str_subseq(str, pos+RSTRING_LEN(sep), RSTRING_LEN(str)-pos-RSTRING_LEN(sep))); }
Prepend—Prepend the given string to str.
a = “world” a.prepend(“hello ”) #=> “hello world” a #=> “hello world”
static VALUE rb_str_prepend(VALUE str, VALUE str2) { StringValue(str2); StringValue(str); rb_str_update(str, 0L, 0L, str2); return str; }
Replaces the contents and taintedness of str with the corresponding values in other_str.
s = "hello" #=> "hello" s.replace "world" #=> "world"
VALUE rb_str_replace(VALUE str, VALUE str2) { str_modifiable(str); if (str == str2) return str; StringValue(str2); str_discard(str); return str_replace(str, str2); }
Returns a new string with the characters from str in reverse order.
"stressed".reverse #=> "desserts"
static VALUE rb_str_reverse(VALUE str) { rb_encoding *enc; VALUE rev; char *s, *e, *p; int single = 1; if (RSTRING_LEN(str) <= 1) return rb_str_dup(str); enc = STR_ENC_GET(str); rev = rb_str_new5(str, 0, RSTRING_LEN(str)); s = RSTRING_PTR(str); e = RSTRING_END(str); p = RSTRING_END(rev); if (RSTRING_LEN(str) > 1) { if (single_byte_optimizable(str)) { while (s < e) { *--p = *s++; } } else if (ENC_CODERANGE(str) == ENC_CODERANGE_VALID) { while (s < e) { int clen = rb_enc_fast_mbclen(s, e, enc); if (clen > 1 || (*s & 0x80)) single = 0; p -= clen; memcpy(p, s, clen); s += clen; } } else { while (s < e) { int clen = rb_enc_mbclen(s, e, enc); if (clen > 1 || (*s & 0x80)) single = 0; p -= clen; memcpy(p, s, clen); s += clen; } } } STR_SET_LEN(rev, RSTRING_LEN(str)); OBJ_INFECT(rev, str); if (ENC_CODERANGE(str) == ENC_CODERANGE_UNKNOWN) { if (single) { ENC_CODERANGE_SET(str, ENC_CODERANGE_7BIT); } else { ENC_CODERANGE_SET(str, ENC_CODERANGE_VALID); } } rb_enc_cr_str_copy_for_substr(rev, str); return rev; }
Reverses str in place.
static VALUE rb_str_reverse_bang(VALUE str) { if (RSTRING_LEN(str) > 1) { if (single_byte_optimizable(str)) { char *s, *e, c; str_modify_keep_cr(str); s = RSTRING_PTR(str); e = RSTRING_END(str) - 1; while (s < e) { c = *s; *s++ = *e; *e-- = c; } } else { rb_str_shared_replace(str, rb_str_reverse(str)); } } else { str_modify_keep_cr(str); } return str; }
Returns the index of the last occurrence of the given substring or
pattern (regexp) in str. Returns nil
if not
found. If the second parameter is present, it specifies the position in the
string to end the search—characters beyond this point will not be
considered.
"hello".rindex('e') #=> 1 "hello".rindex('l') #=> 3 "hello".rindex('a') #=> nil "hello".rindex(?e) #=> 1 "hello".rindex(/[aeiou]/, -2) #=> 1
static VALUE rb_str_rindex_m(int argc, VALUE *argv, VALUE str) { VALUE sub; VALUE vpos; rb_encoding *enc = STR_ENC_GET(str); long pos, len = str_strlen(str, enc); if (rb_scan_args(argc, argv, "11", &sub, &vpos) == 2) { pos = NUM2LONG(vpos); if (pos < 0) { pos += len; if (pos < 0) { if (TYPE(sub) == T_REGEXP) { rb_backref_set(Qnil); } return Qnil; } } if (pos > len) pos = len; } else { pos = len; } switch (TYPE(sub)) { case T_REGEXP: /* enc = rb_get_check(str, sub); */ pos = str_offset(RSTRING_PTR(str), RSTRING_END(str), pos, STR_ENC_GET(str), single_byte_optimizable(str)); if (!RREGEXP(sub)->ptr || RREGEXP_SRC_LEN(sub)) { pos = rb_reg_search(sub, str, pos, 1); pos = rb_str_sublen(str, pos); } if (pos >= 0) return LONG2NUM(pos); break; default: { VALUE tmp; tmp = rb_check_string_type(sub); if (NIL_P(tmp)) { rb_raise(rb_eTypeError, "type mismatch: %s given", rb_obj_classname(sub)); } sub = tmp; } /* fall through */ case T_STRING: pos = rb_str_rindex(str, sub, pos); if (pos >= 0) return LONG2NUM(pos); break; } return Qnil; }
If integer is greater than the length of str, returns a
new String
of length integer with str right
justified and padded with padstr; otherwise, returns str.
"hello".rjust(4) #=> "hello" "hello".rjust(20) #=> " hello" "hello".rjust(20, '1234') #=> "123412341234123hello"
static VALUE rb_str_rjust(int argc, VALUE *argv, VALUE str) { return rb_str_justify(argc, argv, str, 'r'); }
Searches sep or pattern (regexp) in the string from the end of the string, and returns the part before it, the match, and the part after it. If it is not found, returns two empty strings and str.
"hello".rpartition("l") #=> ["hel", "l", "o"] "hello".rpartition("x") #=> ["", "", "hello"] "hello".rpartition(/.l/) #=> ["he", "ll", "o"]
static VALUE rb_str_rpartition(VALUE str, VALUE sep) { long pos = RSTRING_LEN(str); int regex = FALSE; if (TYPE(sep) == T_REGEXP) { pos = rb_reg_search(sep, str, pos, 1); regex = TRUE; } else { VALUE tmp; tmp = rb_check_string_type(sep); if (NIL_P(tmp)) { rb_raise(rb_eTypeError, "type mismatch: %s given", rb_obj_classname(sep)); } sep = tmp; pos = rb_str_sublen(str, pos); pos = rb_str_rindex(str, sep, pos); } if (pos < 0) { return rb_ary_new3(3, str_new_empty(str), str_new_empty(str), str); } if (regex) { sep = rb_reg_nth_match(0, rb_backref_get()); } return rb_ary_new3(3, rb_str_substr(str, 0, pos), sep, rb_str_substr(str,pos+str_strlen(sep,STR_ENC_GET(sep)),RSTRING_LEN(str))); }
Returns a copy of str with trailing whitespace removed. See also
String#lstrip
and String#strip
.
" hello ".rstrip #=> " hello" "hello".rstrip #=> "hello"
static VALUE rb_str_rstrip(VALUE str) { str = rb_str_dup(str); rb_str_rstrip_bang(str); return str; }
Removes trailing whitespace from str, returning nil
if no change was made. See also String#lstrip!
and
String#strip!
.
" hello ".rstrip #=> " hello" "hello".rstrip! #=> nil
static VALUE rb_str_rstrip_bang(VALUE str) { rb_encoding *enc; char *s, *t, *e; str_modify_keep_cr(str); enc = STR_ENC_GET(str); rb_str_check_dummy_enc(enc); s = RSTRING_PTR(str); if (!s || RSTRING_LEN(str) == 0) return Qnil; t = e = RSTRING_END(str); /* remove trailing spaces or '\0's */ if (single_byte_optimizable(str)) { unsigned char c; while (s < t && ((c = *(t-1)) == '\0' || ascii_isspace(c))) t--; } else { char *tp; while ((tp = rb_enc_prev_char(s, t, e, enc)) != NULL) { unsigned int c = rb_enc_codepoint(tp, e, enc); if (c && !rb_isspace(c)) break; t = tp; } } if (t < e) { long len = t-RSTRING_PTR(str); STR_SET_LEN(str, len); RSTRING_PTR(str)[len] = '\0'; return str; } return Qnil; }
Both forms iterate through str, matching the pattern (which may be
a Regexp
or a String
). For each match, a result
is generated and either added to the result array or passed to the block.
If the pattern contains no groups, each individual result consists of the
matched string, $&
. If the pattern contains groups, each
individual result is itself an array containing one entry per group.
a = "cruel world" a.scan(/\w+/) #=> ["cruel", "world"] a.scan(/.../) #=> ["cru", "el ", "wor"] a.scan(/(...)/) #=> [["cru"], ["el "], ["wor"]] a.scan(/(..)(..)/) #=> [["cr", "ue"], ["l ", "wo"]]
And the block form:
a.scan(/\w+/) {|w| print "<<#{w}>> " } print "\n" a.scan(/(.)(.)/) {|x,y| print y, x } print "\n"
produces:
<<cruel>> <<world>> rceu lowlr
static VALUE rb_str_scan(VALUE str, VALUE pat) { VALUE result; long start = 0; long last = -1, prev = 0; char *p = RSTRING_PTR(str); long len = RSTRING_LEN(str); pat = get_pat(pat, 1); if (!rb_block_given_p()) { VALUE ary = rb_ary_new(); while (!NIL_P(result = scan_once(str, pat, &start))) { last = prev; prev = start; rb_ary_push(ary, result); } if (last >= 0) rb_reg_search(pat, str, last, 0); return ary; } while (!NIL_P(result = scan_once(str, pat, &start))) { last = prev; prev = start; rb_yield(result); str_mod_check(str, p, len); } if (last >= 0) rb_reg_search(pat, str, last, 0); return str; }
modifies the indexth byte as int.
static VALUE rb_str_setbyte(VALUE str, VALUE index, VALUE value) { long pos = NUM2LONG(index); int byte = NUM2INT(value); rb_str_modify(str); if (pos < -RSTRING_LEN(str) || RSTRING_LEN(str) <= pos) rb_raise(rb_eIndexError, "index %ld out of string", pos); if (pos < 0) pos += RSTRING_LEN(str); RSTRING_PTR(str)[pos] = byte; return value; }
Returns the character length of str.
VALUE rb_str_length(VALUE str) { long len; len = str_strlen(str, STR_ENC_GET(str)); return LONG2NUM(len); }
Element Reference—If passed a single Fixnum
, returns a
substring of one character at that position. If passed two
Fixnum
objects, returns a substring starting at the offset
given by the first, and with a length given by the second. If passed a
range, its beginning and end are interpreted as offsets delimiting the
substring to be returned. In all three cases, if an offset is negative, it
is counted from the end of str. Returns nil
if the
initial offset falls outside the string or the length is negative.
If a Regexp
is supplied, the matching portion of str
is returned. If a numeric or name parameter follows the regular expression,
that component of the MatchData
is returned instead. If a
String
is given, that string is returned if it occurs in
str. In both cases, nil
is returned if there is no
match.
a = "hello there" a[1] #=> "e" a[2, 3] #=> "llo" a[2..3] #=> "ll" a[-3, 2] #=> "er" a[7..-2] #=> "her" a[-4..-2] #=> "her" a[-2..-4] #=> "" a[12..-1] #=> nil a[/[aeiou](.)\1/] #=> "ell" a[/[aeiou](.)\1/, 0] #=> "ell" a[/[aeiou](.)\1/, 1] #=> "l" a[/[aeiou](.)\1/, 2] #=> nil a["lo"] #=> "lo" a["bye"] #=> nil
static VALUE rb_str_aref_m(int argc, VALUE *argv, VALUE str) { if (argc == 2) { if (TYPE(argv[0]) == T_REGEXP) { return rb_str_subpat(str, argv[0], argv[1]); } return rb_str_substr(str, NUM2LONG(argv[0]), NUM2LONG(argv[1])); } if (argc != 1) { rb_raise(rb_eArgError, "wrong number of arguments (%d for 1..2)", argc); } return rb_str_aref(str, argv[0]); }
Deletes the specified portion from str, and returns the portion deleted.
string = "this is a string" string.slice!(2) #=> "i" string.slice!(3..6) #=> " is " string.slice!(/s.*t/) #=> "sa st" string.slice!("r") #=> "r" string #=> "thing"
static VALUE rb_str_slice_bang(int argc, VALUE *argv, VALUE str) { VALUE result; VALUE buf[3]; int i; if (argc < 1 || 2 < argc) { rb_raise(rb_eArgError, "wrong number of arguments (%d for 1..2)", argc); } for (i=0; i<argc; i++) { buf[i] = argv[i]; } str_modify_keep_cr(str); result = rb_str_aref_m(argc, buf, str); if (!NIL_P(result)) { buf[i] = rb_str_new(0,0); rb_str_aset_m(argc+1, buf, str); } return result; }
Divides str into substrings based on a delimiter, returning an array of these substrings.
If pattern is a String
, then its contents are used as
the delimiter when splitting str. If pattern is a single
space, str is split on whitespace, with leading whitespace and
runs of contiguous whitespace characters ignored.
If pattern is a Regexp
, str is divided where
the pattern matches. Whenever the pattern matches a zero-length string,
str is split into individual characters. If pattern
contains groups, the respective matches will be returned in the array as
well.
If pattern is omitted, the value of $;
is used. If
$;
is nil
(which is the default), str is
split on whitespace as if ` ‘ were specified.
If the limit parameter is omitted, trailing null fields are
suppressed. If limit is a positive number, at most that number of
fields will be returned (if limit is 1
, the entire
string is returned as the only entry in an array). If negative, there is no
limit to the number of fields returned, and trailing null fields are not
suppressed.
" now's the time".split #=> ["now's", "the", "time"] " now's the time".split(' ') #=> ["now's", "the", "time"] " now's the time".split(/ /) #=> ["", "now's", "", "the", "time"] "1, 2.34,56, 7".split(%r{,\s*}) #=> ["1", "2.34", "56", "7"] "hello".split(//) #=> ["h", "e", "l", "l", "o"] "hello".split(//, 3) #=> ["h", "e", "llo"] "hi mom".split(%r{\s*}) #=> ["h", "i", "m", "o", "m"] "mellow yellow".split("ello") #=> ["m", "w y", "w"] "1,2,,3,4,,".split(',') #=> ["1", "2", "", "3", "4"] "1,2,,3,4,,".split(',', 4) #=> ["1", "2", "", "3,4,,"] "1,2,,3,4,,".split(',', -4) #=> ["1", "2", "", "3", "4", "", ""]
static VALUE rb_str_split_m(int argc, VALUE *argv, VALUE str) { rb_encoding *enc; VALUE spat; VALUE limit; enum {awk, string, regexp} split_type; long beg, end, i = 0; int lim = 0; VALUE result, tmp; if (rb_scan_args(argc, argv, "02", &spat, &limit) == 2) { lim = NUM2INT(limit); if (lim <= 0) limit = Qnil; else if (lim == 1) { if (RSTRING_LEN(str) == 0) return rb_ary_new2(0); return rb_ary_new3(1, str); } i = 1; } enc = STR_ENC_GET(str); if (NIL_P(spat)) { if (!NIL_P(rb_fs)) { spat = rb_fs; goto fs_set; } split_type = awk; } else { fs_set: if (TYPE(spat) == T_STRING) { rb_encoding *enc2 = STR_ENC_GET(spat); split_type = string; if (RSTRING_LEN(spat) == 0) { /* Special case - split into chars */ spat = rb_reg_regcomp(spat); split_type = regexp; } else if (rb_enc_asciicompat(enc2) == 1) { if (RSTRING_LEN(spat) == 1 && RSTRING_PTR(spat)[0] == ' '){ split_type = awk; } } else { int l; if (rb_enc_ascget(RSTRING_PTR(spat), RSTRING_END(spat), &l, enc2) == ' ' && RSTRING_LEN(spat) == l) { split_type = awk; } } } else { spat = get_pat(spat, 1); split_type = regexp; } } result = rb_ary_new(); beg = 0; if (split_type == awk) { char *ptr = RSTRING_PTR(str); char *eptr = RSTRING_END(str); char *bptr = ptr; int skip = 1; unsigned int c; end = beg; if (is_ascii_string(str)) { while (ptr < eptr) { c = (unsigned char)*ptr++; if (skip) { if (ascii_isspace(c)) { beg = ptr - bptr; } else { end = ptr - bptr; skip = 0; if (!NIL_P(limit) && lim <= i) break; } } else if (ascii_isspace(c)) { rb_ary_push(result, rb_str_subseq(str, beg, end-beg)); skip = 1; beg = ptr - bptr; if (!NIL_P(limit)) ++i; } else { end = ptr - bptr; } } } else { while (ptr < eptr) { int n; c = rb_enc_codepoint_len(ptr, eptr, &n, enc); ptr += n; if (skip) { if (rb_isspace(c)) { beg = ptr - bptr; } else { end = ptr - bptr; skip = 0; if (!NIL_P(limit) && lim <= i) break; } } else if (rb_isspace(c)) { rb_ary_push(result, rb_str_subseq(str, beg, end-beg)); skip = 1; beg = ptr - bptr; if (!NIL_P(limit)) ++i; } else { end = ptr - bptr; } } } } else if (split_type == string) { char *ptr = RSTRING_PTR(str); char *temp = ptr; char *eptr = RSTRING_END(str); char *sptr = RSTRING_PTR(spat); long slen = RSTRING_LEN(spat); if (is_broken_string(str)) { rb_raise(rb_eArgError, "invalid byte sequence in %s", rb_enc_name(STR_ENC_GET(str))); } if (is_broken_string(spat)) { rb_raise(rb_eArgError, "invalid byte sequence in %s", rb_enc_name(STR_ENC_GET(spat))); } enc = rb_enc_check(str, spat); while (ptr < eptr && (end = rb_memsearch(sptr, slen, ptr, eptr - ptr, enc)) >= 0) { /* Check we are at the start of a char */ char *t = rb_enc_right_char_head(ptr, ptr + end, eptr, enc); if (t != ptr + end) { ptr = t; continue; } rb_ary_push(result, rb_str_subseq(str, ptr - temp, end)); ptr += end + slen; if (!NIL_P(limit) && lim <= ++i) break; } beg = ptr - temp; } else { char *ptr = RSTRING_PTR(str); long len = RSTRING_LEN(str); long start = beg; long idx; int last_null = 0; struct re_registers *regs; while ((end = rb_reg_search(spat, str, start, 0)) >= 0) { regs = RMATCH_REGS(rb_backref_get()); if (start == end && BEG(0) == END(0)) { if (!ptr) { rb_ary_push(result, str_new_empty(str)); break; } else if (last_null == 1) { rb_ary_push(result, rb_str_subseq(str, beg, rb_enc_fast_mbclen(ptr+beg, ptr+len, enc))); beg = start; } else { if (ptr+start == ptr+len) start++; else start += rb_enc_fast_mbclen(ptr+start,ptr+len,enc); last_null = 1; continue; } } else { rb_ary_push(result, rb_str_subseq(str, beg, end-beg)); beg = start = END(0); } last_null = 0; for (idx=1; idx < regs->num_regs; idx++) { if (BEG(idx) == -1) continue; if (BEG(idx) == END(idx)) tmp = str_new_empty(str); else tmp = rb_str_subseq(str, BEG(idx), END(idx)-BEG(idx)); rb_ary_push(result, tmp); } if (!NIL_P(limit) && lim <= ++i) break; } } if (RSTRING_LEN(str) > 0 && (!NIL_P(limit) || RSTRING_LEN(str) > beg || lim < 0)) { if (RSTRING_LEN(str) == beg) tmp = str_new_empty(str); else tmp = rb_str_subseq(str, beg, RSTRING_LEN(str)-beg); rb_ary_push(result, tmp); } if (NIL_P(limit) && lim == 0) { long len; while ((len = RARRAY_LEN(result)) > 0 && (tmp = RARRAY_PTR(result)[len-1], RSTRING_LEN(tmp) == 0)) rb_ary_pop(result); } return result; }
Builds a set of characters from the other_str parameter(s) using
the procedure described for String#count
. Returns a new string
where runs of the same character that occur in this set are replaced by a
single character. If no arguments are given, all runs of identical
characters are replaced by a single character.
"yellow moon".squeeze #=> "yelow mon" " now is the".squeeze(" ") #=> " now is the" "putters shoot balls".squeeze("m-z") #=> "puters shot balls"
static VALUE rb_str_squeeze(int argc, VALUE *argv, VALUE str) { str = rb_str_dup(str); rb_str_squeeze_bang(argc, argv, str); return str; }
Squeezes str in place, returning either str, or
nil
if no changes were made.
static VALUE rb_str_squeeze_bang(int argc, VALUE *argv, VALUE str) { char squeez[TR_TABLE_SIZE]; rb_encoding *enc = 0; VALUE del = 0, nodel = 0; char *s, *send, *t; int i, modify = 0; int ascompat, singlebyte = single_byte_optimizable(str); unsigned int save; if (argc == 0) { enc = STR_ENC_GET(str); } else { for (i=0; i<argc; i++) { VALUE s = argv[i]; StringValue(s); enc = rb_enc_check(str, s); if (singlebyte && !single_byte_optimizable(s)) singlebyte = 0; tr_setup_table(s, squeez, i==0, &del, &nodel, enc); } } str_modify_keep_cr(str); s = t = RSTRING_PTR(str); if (!s || RSTRING_LEN(str) == 0) return Qnil; send = RSTRING_END(str); save = -1; ascompat = rb_enc_asciicompat(enc); if (singlebyte) { while (s < send) { unsigned int c = *(unsigned char*)s++; if (c != save || (argc > 0 && !squeez[c])) { *t++ = save = c; } } } else { while (s < send) { unsigned int c; int clen; if (ascompat && (c = *(unsigned char*)s) < 0x80) { if (c != save || (argc > 0 && !squeez[c])) { *t++ = save = c; } s++; } else { c = rb_enc_codepoint_len(s, send, &clen, enc); if (c != save || (argc > 0 && !tr_find(c, squeez, del, nodel))) { if (t != s) rb_enc_mbcput(c, t, enc); save = c; t += clen; } s += clen; } } } *t = '\0'; if (t - RSTRING_PTR(str) != RSTRING_LEN(str)) { STR_SET_LEN(str, t - RSTRING_PTR(str)); modify = 1; } if (modify) return str; return Qnil; }
Returns true if str starts with one of the prefixes given.
p "hello".start_with?("hell") #=> true # returns true if one of the prefixes matches. p "hello".start_with?("heaven", "hell") #=> true p "hello".start_with?("heaven", "paradise") #=> false
static VALUE rb_str_start_with(int argc, VALUE *argv, VALUE str) { int i; for (i=0; i<argc; i++) { VALUE tmp = rb_check_string_type(argv[i]); if (NIL_P(tmp)) continue; rb_enc_check(str, tmp); if (RSTRING_LEN(str) < RSTRING_LEN(tmp)) continue; if (memcmp(RSTRING_PTR(str), RSTRING_PTR(tmp), RSTRING_LEN(tmp)) == 0) return Qtrue; } return Qfalse; }
Returns a copy of str with leading and trailing whitespace removed.
" hello ".strip #=> "hello" "\tgoodbye\r\n".strip #=> "goodbye"
static VALUE rb_str_strip(VALUE str) { str = rb_str_dup(str); rb_str_strip_bang(str); return str; }
Removes leading and trailing whitespace from str. Returns
nil
if str was not altered.
static VALUE rb_str_strip_bang(VALUE str) { VALUE l = rb_str_lstrip_bang(str); VALUE r = rb_str_rstrip_bang(str); if (NIL_P(l) && NIL_P(r)) return Qnil; return str; }
Returns a copy of str with the first occurrence of
pattern substituted for the second argument. The pattern
is typically a Regexp
; if given as a String
, any
regular expression metacharacters it contains will be interpreted
literally, e.g. '\\d'
will match a backlash followed by ‘d’,
instead of a digit.
If replacement is a String
it will be substituted for
the matched text. It may contain back-references to the pattern’s capture
groups of the form \\d
, where d is a group number, or
\\k<n>
, where n is a group name. If it is a
double-quoted string, both back-references must be preceded by an
additional backslash. However, within replacement the special
match variables, such as &$
, will not refer to the current
match.
If the second argument is a Hash
, and the matched text is one
of its keys, the corresponding value is the replacement string.
In the block form, the current match string is passed in as a parameter,
and variables such as $1
, $2
, $`
,
$&
, and $'
will be set appropriately. The
value returned by the block will be substituted for the match on each call.
The result inherits any tainting in the original string or any supplied replacement string.
"hello".sub(/[aeiou]/, '*') #=> "h*llo" "hello".sub(/([aeiou])/, '<\1>') #=> "h<e>llo" "hello".sub(/./) {|s| s.ord.to_s + ' ' } #=> "104 ello" "hello".sub(/(?<foo>[aeiou])/, '*\k<foo>*') #=> "h*e*llo" 'Is SHELL your preferred shell?'.sub(/[[:upper:]]{2,}/, ENV) #=> "Is /bin/bash your preferred shell?"
static VALUE rb_str_sub(int argc, VALUE *argv, VALUE str) { str = rb_str_dup(str); rb_str_sub_bang(argc, argv, str); return str; }
Performs the substitutions of String#sub
in place, returning
str, or nil
if no substitutions were performed.
static VALUE rb_str_sub_bang(int argc, VALUE *argv, VALUE str) { VALUE pat, repl, hash = Qnil; int iter = 0; int tainted = 0; int untrusted = 0; long plen; if (argc == 1 && rb_block_given_p()) { iter = 1; } else if (argc == 2) { repl = argv[1]; hash = rb_check_convert_type(argv[1], T_HASH, "Hash", "to_hash"); if (NIL_P(hash)) { StringValue(repl); } if (OBJ_TAINTED(repl)) tainted = 1; if (OBJ_UNTRUSTED(repl)) untrusted = 1; } else { rb_raise(rb_eArgError, "wrong number of arguments (%d for 1..2)", argc); } pat = get_pat(argv[0], 1); str_modifiable(str); if (rb_reg_search(pat, str, 0, 0) >= 0) { rb_encoding *enc; int cr = ENC_CODERANGE(str); VALUE match = rb_backref_get(); struct re_registers *regs = RMATCH_REGS(match); long beg0 = BEG(0); long end0 = END(0); char *p, *rp; long len, rlen; if (iter || !NIL_P(hash)) { p = RSTRING_PTR(str); len = RSTRING_LEN(str); if (iter) { repl = rb_obj_as_string(rb_yield(rb_reg_nth_match(0, match))); } else { repl = rb_hash_aref(hash, rb_str_subseq(str, beg0, end0 - beg0)); repl = rb_obj_as_string(repl); } str_mod_check(str, p, len); rb_check_frozen(str); } else { repl = rb_reg_regsub(repl, str, regs, pat); } enc = rb_enc_compatible(str, repl); if (!enc) { rb_encoding *str_enc = STR_ENC_GET(str); p = RSTRING_PTR(str); len = RSTRING_LEN(str); if (coderange_scan(p, beg0, str_enc) != ENC_CODERANGE_7BIT || coderange_scan(p+end0, len-end0, str_enc) != ENC_CODERANGE_7BIT) { rb_raise(rb_eEncCompatError, "incompatible character encodings: %s and %s", rb_enc_name(str_enc), rb_enc_name(STR_ENC_GET(repl))); } enc = STR_ENC_GET(repl); } rb_str_modify(str); rb_enc_associate(str, enc); if (OBJ_TAINTED(repl)) tainted = 1; if (OBJ_UNTRUSTED(repl)) untrusted = 1; if (ENC_CODERANGE_UNKNOWN < cr && cr < ENC_CODERANGE_BROKEN) { int cr2 = ENC_CODERANGE(repl); if (cr2 == ENC_CODERANGE_BROKEN || (cr == ENC_CODERANGE_VALID && cr2 == ENC_CODERANGE_7BIT)) cr = ENC_CODERANGE_UNKNOWN; else cr = cr2; } plen = end0 - beg0; rp = RSTRING_PTR(repl); rlen = RSTRING_LEN(repl); len = RSTRING_LEN(str); if (rlen > plen) { RESIZE_CAPA(str, len + rlen - plen); } p = RSTRING_PTR(str); if (rlen != plen) { memmove(p + beg0 + rlen, p + beg0 + plen, len - beg0 - plen); } memcpy(p + beg0, rp, rlen); len += rlen - plen; STR_SET_LEN(str, len); RSTRING_PTR(str)[len] = '\0'; ENC_CODERANGE_SET(str, cr); if (tainted) OBJ_TAINT(str); if (untrusted) OBJ_UNTRUST(str); return str; } return Qnil; }
Returns the successor to str. The successor is calculated by incrementing characters starting from the rightmost alphanumeric (or the rightmost character if there are no alphanumerics) in the string. Incrementing a digit always results in another digit, and incrementing a letter results in another letter of the same case. Incrementing nonalphanumerics uses the underlying character set’s collating sequence.
If the increment generates a “carry,” the character to the left of it is incremented. This process repeats until there is no carry, adding an additional character if necessary.
"abcd".succ #=> "abce" "THX1138".succ #=> "THX1139" "<<koala>>".succ #=> "<<koalb>>" "1999zzz".succ #=> "2000aaa" "ZZZ9999".succ #=> "AAAA0000" "***".succ #=> "**+"
VALUE rb_str_succ(VALUE orig) { rb_encoding *enc; VALUE str; char *sbeg, *s, *e, *last_alnum = 0; int c = -1; long l; char carry[ONIGENC_CODE_TO_MBC_MAXLEN] = "\1"; long carry_pos = 0, carry_len = 1; enum neighbor_char neighbor = NEIGHBOR_FOUND; str = rb_str_new5(orig, RSTRING_PTR(orig), RSTRING_LEN(orig)); rb_enc_cr_str_copy_for_substr(str, orig); OBJ_INFECT(str, orig); if (RSTRING_LEN(str) == 0) return str; enc = STR_ENC_GET(orig); sbeg = RSTRING_PTR(str); s = e = sbeg + RSTRING_LEN(str); while ((s = rb_enc_prev_char(sbeg, s, e, enc)) != 0) { if (neighbor == NEIGHBOR_NOT_CHAR && last_alnum) { if (ISALPHA(*last_alnum) ? ISDIGIT(*s) : ISDIGIT(*last_alnum) ? ISALPHA(*s) : 0) { s = last_alnum; break; } } if ((l = rb_enc_precise_mbclen(s, e, enc)) <= 0) continue; neighbor = enc_succ_alnum_char(s, l, enc, carry); switch (neighbor) { case NEIGHBOR_NOT_CHAR: continue; case NEIGHBOR_FOUND: return str; case NEIGHBOR_WRAPPED: last_alnum = s; break; } c = 1; carry_pos = s - sbeg; carry_len = l; } if (c == -1) { /* str contains no alnum */ s = e; while ((s = rb_enc_prev_char(sbeg, s, e, enc)) != 0) { enum neighbor_char neighbor; if ((l = rb_enc_precise_mbclen(s, e, enc)) <= 0) continue; neighbor = enc_succ_char(s, l, enc); if (neighbor == NEIGHBOR_FOUND) return str; if (rb_enc_precise_mbclen(s, s+l, enc) != l) { /* wrapped to \0...\0. search next valid char. */ enc_succ_char(s, l, enc); } if (!rb_enc_asciicompat(enc)) { MEMCPY(carry, s, char, l); carry_len = l; } carry_pos = s - sbeg; } } RESIZE_CAPA(str, RSTRING_LEN(str) + carry_len); s = RSTRING_PTR(str) + carry_pos; memmove(s + carry_len, s, RSTRING_LEN(str) - carry_pos); memmove(s, carry, carry_len); STR_SET_LEN(str, RSTRING_LEN(str) + carry_len); RSTRING_PTR(str)[RSTRING_LEN(str)] = '\0'; rb_enc_str_coderange(str); return str; }
Equivalent to String#succ
, but modifies the receiver in place.
static VALUE rb_str_succ_bang(VALUE str) { rb_str_shared_replace(str, rb_str_succ(str)); return str; }
Returns a basic n-bit checksum of the characters in str,
where n is the optional Fixnum
parameter, defaulting
to 16. The result is simply the sum of the binary value of each character
in str modulo 2**n - 1
. This is not a particularly
good checksum.
static VALUE rb_str_sum(int argc, VALUE *argv, VALUE str) { VALUE vbits; int bits; char *ptr, *p, *pend; long len; VALUE sum = INT2FIX(0); unsigned long sum0 = 0; if (argc == 0) { bits = 16; } else { rb_scan_args(argc, argv, "01", &vbits); bits = NUM2INT(vbits); } ptr = p = RSTRING_PTR(str); len = RSTRING_LEN(str); pend = p + len; while (p < pend) { if (FIXNUM_MAX - UCHAR_MAX < sum0) { sum = rb_funcall(sum, '+', 1, LONG2FIX(sum0)); str_mod_check(str, ptr, len); sum0 = 0; } sum0 += (unsigned char)*p; p++; } if (bits == 0) { if (sum0) { sum = rb_funcall(sum, '+', 1, LONG2FIX(sum0)); } } else { if (sum == INT2FIX(0)) { if (bits < (int)sizeof(long)*CHAR_BIT) { sum0 &= (((unsigned long)1)<<bits)-1; } sum = LONG2FIX(sum0); } else { VALUE mod; if (sum0) { sum = rb_funcall(sum, '+', 1, LONG2FIX(sum0)); } mod = rb_funcall(INT2FIX(1), rb_intern("<<"), 1, INT2FIX(bits)); mod = rb_funcall(mod, '-', 1, INT2FIX(1)); sum = rb_funcall(sum, '&', 1, mod); } } return sum; }
Returns a copy of str with uppercase alphabetic characters converted to lowercase and lowercase characters converted to uppercase. Note: case conversion is effective only in ASCII region.
"Hello".swapcase #=> "hELLO" "cYbEr_PuNk11".swapcase #=> "CyBeR_pUnK11"
static VALUE rb_str_swapcase(VALUE str) { str = rb_str_dup(str); rb_str_swapcase_bang(str); return str; }
Equivalent to String#swapcase
, but modifies the receiver in
place, returning str, or nil
if no changes were made.
Note: case conversion is effective only in ASCII region.
static VALUE rb_str_swapcase_bang(VALUE str) { rb_encoding *enc; char *s, *send; int modify = 0; int n; str_modify_keep_cr(str); enc = STR_ENC_GET(str); rb_str_check_dummy_enc(enc); s = RSTRING_PTR(str); send = RSTRING_END(str); while (s < send) { unsigned int c = rb_enc_codepoint_len(s, send, &n, enc); if (rb_enc_isupper(c, enc)) { /* assuming toupper returns codepoint with same size */ rb_enc_mbcput(rb_enc_tolower(c, enc), s, enc); modify = 1; } else if (rb_enc_islower(c, enc)) { /* assuming tolower returns codepoint with same size */ rb_enc_mbcput(rb_enc_toupper(c, enc), s, enc); modify = 1; } s += n; } if (modify) return str; return Qnil; }
Returns a complex which denotes the string form. The parser ignores leading whitespaces and trailing garbage. Any digit sequences can be separated by an underscore. Returns zero for null or garbage string.
For example:
'9'.to_c #=> (9+0i) '2.5'.to_c #=> (2.5+0i) '2.5/1'.to_c #=> ((5/2)+0i) '-3/2'.to_c #=> ((-3/2)+0i) '-i'.to_c #=> (0-1i) '45i'.to_c #=> (0+45i) '3-4i'.to_c #=> (3-4i) '-4e2-4e-2i'.to_c #=> (-400.0-0.04i) '-0.0-0.0i'.to_c #=> (-0.0-0.0i) '1/2+3/4i'.to_c #=> ((1/2)+(3/4)*i) 'ruby'.to_c #=> (0+0i)
static VALUE string_to_c(VALUE self) { VALUE s, a, backref; backref = rb_backref_get(); rb_match_busy(backref); s = f_gsub(self, underscores_pat, an_underscore); a = string_to_c_internal(s); rb_backref_set(backref); if (!NIL_P(RARRAY_PTR(a)[0])) return RARRAY_PTR(a)[0]; return rb_complex_new1(INT2FIX(0)); }
Returns the result of interpreting leading characters in str as a
floating point number. Extraneous characters past the end of a valid number
are ignored. If there is not a valid number at the start of str,
0.0
is returned. This method never raises an exception.
"123.45e1".to_f #=> 1234.5 "45.67 degrees".to_f #=> 45.67 "thx1138".to_f #=> 0.0
static VALUE rb_str_to_f(VALUE str) { return DBL2NUM(rb_str_to_dbl(str, FALSE)); }
Returns the result of interpreting leading characters in str as an
integer base base (between 2 and 36). Extraneous characters past
the end of a valid number are ignored. If there is not a valid number at
the start of str, 0
is returned. This method never
raises an exception when base is valid.
"12345".to_i #=> 12345 "99 red balloons".to_i #=> 99 "0a".to_i #=> 0 "0a".to_i(16) #=> 10 "hello".to_i #=> 0 "1100101".to_i(2) #=> 101 "1100101".to_i(8) #=> 294977 "1100101".to_i(10) #=> 1100101 "1100101".to_i(16) #=> 17826049
static VALUE rb_str_to_i(int argc, VALUE *argv, VALUE str) { int base; if (argc == 0) base = 10; else { VALUE b; rb_scan_args(argc, argv, "01", &b); base = NUM2INT(b); } if (base < 0) { rb_raise(rb_eArgError, "invalid radix %d", base); } return rb_str_to_inum(str, base, FALSE); }
Returns a rational which denotes the string form. The parser ignores leading whitespaces and trailing garbage. Any digit sequences can be separated by an underscore. Returns zero for null or garbage string.
NOTE: ‘0.3’.to_r isn’t the same as 0.3.to_r. The former is equivalent to ‘3/10’.to_r, but the latter isn’t so.
For example:
' 2 '.to_r #=> (2/1) '300/2'.to_r #=> (150/1) '-9.2'.to_r #=> (-46/5) '-9.2e2'.to_r #=> (-920/1) '1_234_567'.to_r #=> (1234567/1) '21 june 09'.to_r #=> (21/1) '21/06/09'.to_r #=> (7/2) 'bwv 1079'.to_r #=> (0/1)
static VALUE string_to_r(VALUE self) { VALUE s, a, a1, backref; backref = rb_backref_get(); rb_match_busy(backref); s = f_gsub(self, underscores_pat, an_underscore); a = string_to_r_internal(s); rb_backref_set(backref); a1 = RARRAY_PTR(a)[0]; if (!NIL_P(a1)) { if (TYPE(a1) == T_FLOAT) rb_raise(rb_eFloatDomainError, "Infinity"); return a1; } return rb_rational_new1(INT2FIX(0)); }
Returns the receiver.
static VALUE rb_str_to_s(VALUE str) { if (rb_obj_class(str) != rb_cString) { return str_duplicate(rb_cString, str); } return str; }
Returns the receiver.
static VALUE rb_str_to_s(VALUE str) { if (rb_obj_class(str) != rb_cString) { return str_duplicate(rb_cString, str); } return str; }
Returns the Symbol
corresponding to str, creating the
symbol if it did not previously exist. See Symbol#id2name
.
"Koala".intern #=> :Koala s = 'cat'.to_sym #=> :cat s == :cat #=> true s = '@cat'.to_sym #=> :@cat s == :@cat #=> true
This can also be used to create symbols that cannot be represented using
the :xxx
notation.
'cat and dog'.to_sym #=> :"cat and dog"
VALUE rb_str_intern(VALUE s) { VALUE str = RB_GC_GUARD(s); ID id; id = rb_intern_str(str); return ID2SYM(id); }
Returns a copy of str with the characters in from_str replaced by the corresponding characters in to_str. If to_str is shorter than from_str, it is padded with its last character in order to maintain the correspondence.
"hello".tr('el', 'ip') #=> "hippo" "hello".tr('aeiou', '*') #=> "h*ll*"
Both strings may use the c1-c2 notation to denote ranges of characters, and
from_str may start with a ^
, which denotes all
characters except those listed.
"hello".tr('a-y', 'b-z') #=> "ifmmp" "hello".tr('^aeiou', '*') #=> "*e**o"
static VALUE rb_str_tr(VALUE str, VALUE src, VALUE repl) { str = rb_str_dup(str); tr_trans(str, src, repl, 0); return str; }
Translates str in place, using the same rules as
String#tr
. Returns str, or nil
if no
changes were made.
static VALUE rb_str_tr_bang(VALUE str, VALUE src, VALUE repl) { return tr_trans(str, src, repl, 0); }
Processes a copy of str as described under String#tr
,
then removes duplicate characters in regions that were affected by the
translation.
"hello".tr_s('l', 'r') #=> "hero" "hello".tr_s('el', '*') #=> "h*o" "hello".tr_s('el', 'hx') #=> "hhxo"
static VALUE rb_str_tr_s(VALUE str, VALUE src, VALUE repl) { str = rb_str_dup(str); tr_trans(str, src, repl, 1); return str; }
Performs String#tr_s
processing on str in place,
returning str, or nil
if no changes were made.
static VALUE rb_str_tr_s_bang(VALUE str, VALUE src, VALUE repl) { return tr_trans(str, src, repl, 1); }
Decodes str (which may contain binary data) according to the
format string, returning an array of each value extracted. The format
string consists of a sequence of single-character directives, summarized in
the table at the end of this entry. Each directive may be followed by a
number, indicating the number of times to repeat with this directive. An
asterisk (“*
”) will use up all remaining elements. The
directives sSiIlL
may each be followed by an underscore
(“_
”) or exclamation mark (“!
”) to use the
underlying platform’s native size for the specified type; otherwise, it
uses a platform-independent consistent size. Spaces are ignored in the
format string. See also Array#pack
.
"abc \0\0abc \0\0".unpack('A6Z6') #=> ["abc", "abc "] "abc \0\0".unpack('a3a3') #=> ["abc", " \000\000"] "abc \0abc \0".unpack('Z*Z*') #=> ["abc ", "abc "] "aa".unpack('b8B8') #=> ["10000110", "01100001"] "aaa".unpack('h2H2c') #=> ["16", "61", 97] "\xfe\xff\xfe\xff".unpack('sS') #=> [-2, 65534] "now=20is".unpack('M*') #=> ["now is"] "whole".unpack('xax2aX2aX1aX2a') #=> ["h", "e", "l", "l", "o"]
This table summarizes the various formats and the Ruby classes returned by each.
Integer | | Directive | Returns | Meaning ----------------------------------------------------------------- C | Integer | 8-bit unsigned (unsigned char) S | Integer | 16-bit unsigned, native endian (uint16_t) L | Integer | 32-bit unsigned, native endian (uint32_t) Q | Integer | 64-bit unsigned, native endian (uint64_t) | | c | Integer | 8-bit signed (signed char) s | Integer | 16-bit signed, native endian (int16_t) l | Integer | 32-bit signed, native endian (int32_t) q | Integer | 64-bit signed, native endian (int64_t) | | S_, S! | Integer | unsigned short, native endian I, I_, I! | Integer | unsigned int, native endian L_, L! | Integer | unsigned long, native endian | | s_, s! | Integer | signed short, native endian i, i_, i! | Integer | signed int, native endian l_, l! | Integer | signed long, native endian | | S> L> Q> | Integer | same as the directives without ">" except s> l> q> | | big endian S!> I!> | | (available since Ruby 1.9.3) L!> Q!> | | "S>" is same as "n" s!> i!> | | "L>" is same as "N" l!> q!> | | | | S< L< Q< | Integer | same as the directives without "<" except s< l< q< | | little endian S!< I!< | | (available since Ruby 1.9.3) L!< Q!< | | "S<" is same as "v" s!< i!< | | "L<" is same as "V" l!< q!< | | | | n | Integer | 16-bit unsigned, network (big-endian) byte order N | Integer | 32-bit unsigned, network (big-endian) byte order v | Integer | 16-bit unsigned, VAX (little-endian) byte order V | Integer | 32-bit unsigned, VAX (little-endian) byte order | | U | Integer | UTF-8 character w | Integer | BER-compressed integer (see Array.pack) Float | | Directive | Returns | Meaning ----------------------------------------------------------------- D, d | Float | double-precision, native format F, f | Float | single-precision, native format E | Float | double-precision, little-endian byte order e | Float | single-precision, little-endian byte order G | Float | double-precision, network (big-endian) byte order g | Float | single-precision, network (big-endian) byte order String | | Directive | Returns | Meaning ----------------------------------------------------------------- A | String | arbitrary binary string (remove trailing nulls and ASCII spaces) a | String | arbitrary binary string Z | String | null-terminated string B | String | bit string (MSB first) b | String | bit string (LSB first) H | String | hex string (high nibble first) h | String | hex string (low nibble first) u | String | UU-encoded string M | String | quoted-printable, MIME encoding (see RFC2045) m | String | base64 encoded string (RFC 2045) (default) | | base64 encoded string (RFC 4648) if followed by 0 P | String | pointer to a structure (fixed-length string) p | String | pointer to a null-terminated string Misc. | | Directive | Returns | Meaning ----------------------------------------------------------------- @ | --- | skip to the offset given by the length argument X | --- | skip backward one byte x | --- | skip forward one byte
static VALUE pack_unpack(VALUE str, VALUE fmt) { static const char hexdigits[] = "0123456789abcdef"; char *s, *send; char *p, *pend; VALUE ary; char type; long len, tmp_len; int star; #ifdef NATINT_PACK int natint; /* native integer */ #endif int block_p = rb_block_given_p(); int signed_p, integer_size, bigendian_p; #define UNPACK_PUSH(item) do {\ VALUE item_val = (item);\ if (block_p) {\ rb_yield(item_val);\ }\ else {\ rb_ary_push(ary, item_val);\ }\ } while (0) StringValue(str); StringValue(fmt); s = RSTRING_PTR(str); send = s + RSTRING_LEN(str); p = RSTRING_PTR(fmt); pend = p + RSTRING_LEN(fmt); ary = block_p ? Qnil : rb_ary_new(); while (p < pend) { int explicit_endian = 0; type = *p++; #ifdef NATINT_PACK natint = 0; #endif if (ISSPACE(type)) continue; if (type == '#') { while ((p < pend) && (*p != '\n')) { p++; } continue; } star = 0; { static const char natstr[] = "sSiIlL"; static const char endstr[] = "sSiIlLqQ"; modifiers: switch (*p) { case '_': case '!': if (strchr(natstr, type)) { #ifdef NATINT_PACK natint = 1; #endif p++; } else { rb_raise(rb_eArgError, "'%c' allowed only after types %s", *p, natstr); } goto modifiers; case '<': case '>': if (!strchr(endstr, type)) { rb_raise(rb_eArgError, "'%c' allowed only after types %s", *p, endstr); } if (explicit_endian) { rb_raise(rb_eRangeError, "Can't use both '<' and '>'"); } explicit_endian = *p++; goto modifiers; } } if (p >= pend) len = 1; else if (*p == '*') { star = 1; len = send - s; p++; } else if (ISDIGIT(*p)) { errno = 0; len = STRTOUL(p, (char**)&p, 10); if (errno) { rb_raise(rb_eRangeError, "pack length too big"); } } else { len = (type != '@'); } switch (type) { case '%': rb_raise(rb_eArgError, "%% is not supported"); break; case 'A': if (len > send - s) len = send - s; { long end = len; char *t = s + len - 1; while (t >= s) { if (*t != ' ' && *t != '\0') break; t--; len--; } UNPACK_PUSH(infected_str_new(s, len, str)); s += end; } break; case 'Z': { char *t = s; if (len > send-s) len = send-s; while (t < s+len && *t) t++; UNPACK_PUSH(infected_str_new(s, t-s, str)); if (t < send) t++; s = star ? t : s+len; } break; case 'a': if (len > send - s) len = send - s; UNPACK_PUSH(infected_str_new(s, len, str)); s += len; break; case 'b': { VALUE bitstr; char *t; int bits; long i; if (p[-1] == '*' || len > (send - s) * 8) len = (send - s) * 8; bits = 0; UNPACK_PUSH(bitstr = rb_str_new(0, len)); t = RSTRING_PTR(bitstr); for (i=0; i<len; i++) { if (i & 7) bits >>= 1; else bits = *s++; *t++ = (bits & 1) ? '1' : '0'; } } break; case 'B': { VALUE bitstr; char *t; int bits; long i; if (p[-1] == '*' || len > (send - s) * 8) len = (send - s) * 8; bits = 0; UNPACK_PUSH(bitstr = rb_str_new(0, len)); t = RSTRING_PTR(bitstr); for (i=0; i<len; i++) { if (i & 7) bits <<= 1; else bits = *s++; *t++ = (bits & 128) ? '1' : '0'; } } break; case 'h': { VALUE bitstr; char *t; int bits; long i; if (p[-1] == '*' || len > (send - s) * 2) len = (send - s) * 2; bits = 0; UNPACK_PUSH(bitstr = rb_str_new(0, len)); t = RSTRING_PTR(bitstr); for (i=0; i<len; i++) { if (i & 1) bits >>= 4; else bits = *s++; *t++ = hexdigits[bits & 15]; } } break; case 'H': { VALUE bitstr; char *t; int bits; long i; if (p[-1] == '*' || len > (send - s) * 2) len = (send - s) * 2; bits = 0; UNPACK_PUSH(bitstr = rb_str_new(0, len)); t = RSTRING_PTR(bitstr); for (i=0; i<len; i++) { if (i & 1) bits <<= 4; else bits = *s++; *t++ = hexdigits[(bits >> 4) & 15]; } } break; case 'c': PACK_LENGTH_ADJUST_SIZE(sizeof(char)); while (len-- > 0) { int c = *s++; if (c > (char)127) c-=256; UNPACK_PUSH(INT2FIX(c)); } PACK_ITEM_ADJUST(); break; case 'C': PACK_LENGTH_ADJUST_SIZE(sizeof(unsigned char)); while (len-- > 0) { unsigned char c = *s++; UNPACK_PUSH(INT2FIX(c)); } PACK_ITEM_ADJUST(); break; case 's': signed_p = 1; integer_size = NATINT_LEN(short, 2); bigendian_p = BIGENDIAN_P(); goto unpack_integer; case 'S': signed_p = 0; integer_size = NATINT_LEN(short, 2); bigendian_p = BIGENDIAN_P(); goto unpack_integer; case 'i': signed_p = 1; integer_size = (int)sizeof(int); bigendian_p = BIGENDIAN_P(); goto unpack_integer; case 'I': signed_p = 0; integer_size = (int)sizeof(int); bigendian_p = BIGENDIAN_P(); goto unpack_integer; case 'l': signed_p = 1; integer_size = NATINT_LEN(long, 4); bigendian_p = BIGENDIAN_P(); goto unpack_integer; case 'L': signed_p = 0; integer_size = NATINT_LEN(long, 4); bigendian_p = BIGENDIAN_P(); goto unpack_integer; case 'q': signed_p = 1; integer_size = 8; bigendian_p = BIGENDIAN_P(); goto unpack_integer; case 'Q': signed_p = 0; integer_size = 8; bigendian_p = BIGENDIAN_P(); goto unpack_integer; case 'n': signed_p = 0; integer_size = 2; bigendian_p = 1; goto unpack_integer; case 'N': signed_p = 0; integer_size = 4; bigendian_p = 1; goto unpack_integer; case 'v': signed_p = 0; integer_size = 2; bigendian_p = 0; goto unpack_integer; case 'V': signed_p = 0; integer_size = 4; bigendian_p = 0; goto unpack_integer; unpack_integer: if (explicit_endian) { bigendian_p = explicit_endian == '>'; } switch (integer_size) { #if defined(HAVE_INT16_T) && !defined(FORCE_BIG_PACK) case SIZEOF_INT16_T: if (signed_p) { PACK_LENGTH_ADJUST_SIZE(sizeof(int16_t)); while (len-- > 0) { union { int16_t i; char a[sizeof(int16_t)]; } v; memcpy(v.a, s, sizeof(int16_t)); if (bigendian_p != BIGENDIAN_P()) v.i = swap16(v.i); s += sizeof(int16_t); UNPACK_PUSH(INT2FIX(v.i)); } PACK_ITEM_ADJUST(); } else { PACK_LENGTH_ADJUST_SIZE(sizeof(uint16_t)); while (len-- > 0) { union { uint16_t i; char a[sizeof(uint16_t)]; } v; memcpy(v.a, s, sizeof(uint16_t)); if (bigendian_p != BIGENDIAN_P()) v.i = swap16(v.i); s += sizeof(uint16_t); UNPACK_PUSH(INT2FIX(v.i)); } PACK_ITEM_ADJUST(); } break; #endif #if defined(HAVE_INT32_T) && !defined(FORCE_BIG_PACK) case SIZEOF_INT32_T: if (signed_p) { PACK_LENGTH_ADJUST_SIZE(sizeof(int32_t)); while (len-- > 0) { union { int32_t i; char a[sizeof(int32_t)]; } v; memcpy(v.a, s, sizeof(int32_t)); if (bigendian_p != BIGENDIAN_P()) v.i = swap32(v.i); s += sizeof(int32_t); UNPACK_PUSH(INT2NUM(v.i)); } PACK_ITEM_ADJUST(); } else { PACK_LENGTH_ADJUST_SIZE(sizeof(uint32_t)); while (len-- > 0) { union { uint32_t i; char a[sizeof(uint32_t)]; } v; memcpy(v.a, s, sizeof(uint32_t)); if (bigendian_p != BIGENDIAN_P()) v.i = swap32(v.i); s += sizeof(uint32_t); UNPACK_PUSH(UINT2NUM(v.i)); } PACK_ITEM_ADJUST(); } break; #endif #if defined(HAVE_INT64_T) && !defined(FORCE_BIG_PACK) case SIZEOF_INT64_T: if (signed_p) { PACK_LENGTH_ADJUST_SIZE(sizeof(int64_t)); while (len-- > 0) { union { int64_t i; char a[sizeof(int64_t)]; } v; memcpy(v.a, s, sizeof(int64_t)); if (bigendian_p != BIGENDIAN_P()) v.i = swap64(v.i); s += sizeof(int64_t); UNPACK_PUSH(INT64toNUM(v.i)); } PACK_ITEM_ADJUST(); } else { PACK_LENGTH_ADJUST_SIZE(sizeof(uint64_t)); while (len-- > 0) { union { uint64_t i; char a[sizeof(uint64_t)]; } v; memcpy(v.a, s, sizeof(uint64_t)); if (bigendian_p != BIGENDIAN_P()) v.i = swap64(v.i); s += sizeof(uint64_t); UNPACK_PUSH(UINT64toNUM(v.i)); } PACK_ITEM_ADJUST(); } break; #endif default: if (integer_size > MAX_INTEGER_PACK_SIZE) rb_bug("unexpected intger size for pack: %d", integer_size); PACK_LENGTH_ADJUST_SIZE(integer_size); while (len-- > 0) { union { unsigned long i[(MAX_INTEGER_PACK_SIZE+SIZEOF_LONG)/SIZEOF_LONG]; char a[(MAX_INTEGER_PACK_SIZE+SIZEOF_LONG)/SIZEOF_LONG*SIZEOF_LONG]; } v; int num_longs = (integer_size+SIZEOF_LONG)/SIZEOF_LONG; int i; if (signed_p && (signed char)s[bigendian_p ? 0 : (integer_size-1)] < 0) memset(v.a, 0xff, sizeof(long)*num_longs); else memset(v.a, 0, sizeof(long)*num_longs); if (bigendian_p) memcpy(v.a + sizeof(long)*num_longs - integer_size, s, integer_size); else memcpy(v.a, s, integer_size); if (bigendian_p) { for (i = 0; i < num_longs/2; i++) { unsigned long t = v.i[i]; v.i[i] = v.i[num_longs-1-i]; v.i[num_longs-1-i] = t; } } if (bigendian_p != BIGENDIAN_P()) { for (i = 0; i < num_longs; i++) v.i[i] = swapl(v.i[i]); } s += integer_size; UNPACK_PUSH(rb_big_unpack(v.i, num_longs)); } PACK_ITEM_ADJUST(); break; } break; case 'f': case 'F': PACK_LENGTH_ADJUST_SIZE(sizeof(float)); while (len-- > 0) { float tmp; memcpy(&tmp, s, sizeof(float)); s += sizeof(float); UNPACK_PUSH(DBL2NUM((double)tmp)); } PACK_ITEM_ADJUST(); break; case 'e': PACK_LENGTH_ADJUST_SIZE(sizeof(float)); while (len-- > 0) { float tmp; FLOAT_CONVWITH(ftmp); memcpy(&tmp, s, sizeof(float)); s += sizeof(float); tmp = VTOHF(tmp,ftmp); UNPACK_PUSH(DBL2NUM((double)tmp)); } PACK_ITEM_ADJUST(); break; case 'E': PACK_LENGTH_ADJUST_SIZE(sizeof(double)); while (len-- > 0) { double tmp; DOUBLE_CONVWITH(dtmp); memcpy(&tmp, s, sizeof(double)); s += sizeof(double); tmp = VTOHD(tmp,dtmp); UNPACK_PUSH(DBL2NUM(tmp)); } PACK_ITEM_ADJUST(); break; case 'D': case 'd': PACK_LENGTH_ADJUST_SIZE(sizeof(double)); while (len-- > 0) { double tmp; memcpy(&tmp, s, sizeof(double)); s += sizeof(double); UNPACK_PUSH(DBL2NUM(tmp)); } PACK_ITEM_ADJUST(); break; case 'g': PACK_LENGTH_ADJUST_SIZE(sizeof(float)); while (len-- > 0) { float tmp; FLOAT_CONVWITH(ftmp); memcpy(&tmp, s, sizeof(float)); s += sizeof(float); tmp = NTOHF(tmp,ftmp); UNPACK_PUSH(DBL2NUM((double)tmp)); } PACK_ITEM_ADJUST(); break; case 'G': PACK_LENGTH_ADJUST_SIZE(sizeof(double)); while (len-- > 0) { double tmp; DOUBLE_CONVWITH(dtmp); memcpy(&tmp, s, sizeof(double)); s += sizeof(double); tmp = NTOHD(tmp,dtmp); UNPACK_PUSH(DBL2NUM(tmp)); } PACK_ITEM_ADJUST(); break; case 'U': if (len > send - s) len = send - s; while (len > 0 && s < send) { long alen = send - s; unsigned long l; l = utf8_to_uv(s, &alen); s += alen; len--; UNPACK_PUSH(ULONG2NUM(l)); } break; case 'u': { VALUE buf = infected_str_new(0, (send - s)*3/4, str); char *ptr = RSTRING_PTR(buf); long total = 0; while (s < send && *s > ' ' && *s < 'a') { long a,b,c,d; char hunk[4]; hunk[3] = '\0'; len = (*s++ - ' ') & 077; total += len; if (total > RSTRING_LEN(buf)) { len -= total - RSTRING_LEN(buf); total = RSTRING_LEN(buf); } while (len > 0) { long mlen = len > 3 ? 3 : len; if (s < send && *s >= ' ') a = (*s++ - ' ') & 077; else a = 0; if (s < send && *s >= ' ') b = (*s++ - ' ') & 077; else b = 0; if (s < send && *s >= ' ') c = (*s++ - ' ') & 077; else c = 0; if (s < send && *s >= ' ') d = (*s++ - ' ') & 077; else d = 0; hunk[0] = (char)(a << 2 | b >> 4); hunk[1] = (char)(b << 4 | c >> 2); hunk[2] = (char)(c << 6 | d); memcpy(ptr, hunk, mlen); ptr += mlen; len -= mlen; } if (*s == '\r') s++; if (*s == '\n') s++; else if (s < send && (s+1 == send || s[1] == '\n')) s += 2; /* possible checksum byte */ } rb_str_set_len(buf, total); UNPACK_PUSH(buf); } break; case 'm': { VALUE buf = infected_str_new(0, (send - s)*3/4, str); char *ptr = RSTRING_PTR(buf); int a = -1,b = -1,c = 0,d = 0; static signed char b64_xtable[256]; if (b64_xtable['/'] <= 0) { int i; for (i = 0; i < 256; i++) { b64_xtable[i] = -1; } for (i = 0; i < 64; i++) { b64_xtable[(unsigned char)b64_table[i]] = i; } } if (len == 0) { while (s < send) { a = b = c = d = -1; a = b64_xtable[(unsigned char)*s++]; if (s >= send || a == -1) rb_raise(rb_eArgError, "invalid base64"); b = b64_xtable[(unsigned char)*s++]; if (s >= send || b == -1) rb_raise(rb_eArgError, "invalid base64"); if (*s == '=') { if (s + 2 == send && *(s + 1) == '=') break; rb_raise(rb_eArgError, "invalid base64"); } c = b64_xtable[(unsigned char)*s++]; if (s >= send || c == -1) rb_raise(rb_eArgError, "invalid base64"); if (s + 1 == send && *s == '=') break; d = b64_xtable[(unsigned char)*s++]; if (d == -1) rb_raise(rb_eArgError, "invalid base64"); *ptr++ = a << 2 | b >> 4; *ptr++ = b << 4 | c >> 2; *ptr++ = c << 6 | d; } if (c == -1) { *ptr++ = a << 2 | b >> 4; if (b & 0xf) rb_raise(rb_eArgError, "invalid base64"); } else if (d == -1) { *ptr++ = a << 2 | b >> 4; *ptr++ = b << 4 | c >> 2; if (c & 0x3) rb_raise(rb_eArgError, "invalid base64"); } } else { while (s < send) { a = b = c = d = -1; while ((a = b64_xtable[(unsigned char)*s]) == -1 && s < send) {s++;} if (s >= send) break; s++; while ((b = b64_xtable[(unsigned char)*s]) == -1 && s < send) {s++;} if (s >= send) break; s++; while ((c = b64_xtable[(unsigned char)*s]) == -1 && s < send) {if (*s == '=') break; s++;} if (*s == '=' || s >= send) break; s++; while ((d = b64_xtable[(unsigned char)*s]) == -1 && s < send) {if (*s == '=') break; s++;} if (*s == '=' || s >= send) break; s++; *ptr++ = a << 2 | b >> 4; *ptr++ = b << 4 | c >> 2; *ptr++ = c << 6 | d; } if (a != -1 && b != -1) { if (c == -1 && *s == '=') *ptr++ = a << 2 | b >> 4; else if (c != -1 && *s == '=') { *ptr++ = a << 2 | b >> 4; *ptr++ = b << 4 | c >> 2; } } } rb_str_set_len(buf, ptr - RSTRING_PTR(buf)); UNPACK_PUSH(buf); } break; case 'M': { VALUE buf = infected_str_new(0, send - s, str); char *ptr = RSTRING_PTR(buf), *ss = s; int c1, c2; while (s < send) { if (*s == '=') { if (++s == send) break; if (s+1 < send && *s == '\r' && *(s+1) == '\n') s++; if (*s != '\n') { if ((c1 = hex2num(*s)) == -1) break; if (++s == send) break; if ((c2 = hex2num(*s)) == -1) break; *ptr++ = c1 << 4 | c2; } } else { *ptr++ = *s; } s++; ss = s; } rb_str_set_len(buf, ptr - RSTRING_PTR(buf)); rb_str_buf_cat(buf, ss, send-ss); ENCODING_CODERANGE_SET(buf, rb_ascii8bit_encindex(), ENC_CODERANGE_VALID); UNPACK_PUSH(buf); } break; case '@': if (len > RSTRING_LEN(str)) rb_raise(rb_eArgError, "@ outside of string"); s = RSTRING_PTR(str) + len; break; case 'X': if (len > s - RSTRING_PTR(str)) rb_raise(rb_eArgError, "X outside of string"); s -= len; break; case 'x': if (len > send - s) rb_raise(rb_eArgError, "x outside of string"); s += len; break; case 'P': if (sizeof(char *) <= (size_t)(send - s)) { VALUE tmp = Qnil; char *t; memcpy(&t, s, sizeof(char *)); s += sizeof(char *); if (t) { VALUE a, *p, *pend; if (!(a = rb_str_associated(str))) { rb_raise(rb_eArgError, "no associated pointer"); } p = RARRAY_PTR(a); pend = p + RARRAY_LEN(a); while (p < pend) { if (TYPE(*p) == T_STRING && RSTRING_PTR(*p) == t) { if (len < RSTRING_LEN(*p)) { tmp = rb_tainted_str_new(t, len); rb_str_associate(tmp, a); } else { tmp = *p; } break; } p++; } if (p == pend) { rb_raise(rb_eArgError, "non associated pointer"); } } UNPACK_PUSH(tmp); } break; case 'p': if (len > (long)((send - s) / sizeof(char *))) len = (send - s) / sizeof(char *); while (len-- > 0) { if ((size_t)(send - s) < sizeof(char *)) break; else { VALUE tmp = Qnil; char *t; memcpy(&t, s, sizeof(char *)); s += sizeof(char *); if (t) { VALUE a, *p, *pend; if (!(a = rb_str_associated(str))) { rb_raise(rb_eArgError, "no associated pointer"); } p = RARRAY_PTR(a); pend = p + RARRAY_LEN(a); while (p < pend) { if (TYPE(*p) == T_STRING && RSTRING_PTR(*p) == t) { tmp = *p; break; } p++; } if (p == pend) { rb_raise(rb_eArgError, "non associated pointer"); } } UNPACK_PUSH(tmp); } } break; case 'w': { unsigned long ul = 0; unsigned long ulmask = 0xfeUL << ((sizeof(unsigned long) - 1) * 8); while (len > 0 && s < send) { ul <<= 7; ul |= (*s & 0x7f); if (!(*s++ & 0x80)) { UNPACK_PUSH(ULONG2NUM(ul)); len--; ul = 0; } else if (ul & ulmask) { VALUE big = rb_uint2big(ul); VALUE big128 = rb_uint2big(128); while (s < send) { big = rb_big_mul(big, big128); big = rb_big_plus(big, rb_uint2big(*s & 0x7f)); if (!(*s++ & 0x80)) { UNPACK_PUSH(big); len--; ul = 0; break; } } } } } break; default: break; } } return ary; }
Returns a copy of str with all lowercase letters replaced with their uppercase counterparts. The operation is locale insensitive—only characters “a” to “z” are affected. Note: case replacement is effective only in ASCII region.
"hEllO".upcase #=> "HELLO"
static VALUE rb_str_upcase(VALUE str) { str = rb_str_dup(str); rb_str_upcase_bang(str); return str; }
Upcases the contents of str, returning nil
if no
changes were made. Note: case replacement is effective only in ASCII
region.
static VALUE rb_str_upcase_bang(VALUE str) { rb_encoding *enc; char *s, *send; int modify = 0; int n; str_modify_keep_cr(str); enc = STR_ENC_GET(str); rb_str_check_dummy_enc(enc); s = RSTRING_PTR(str); send = RSTRING_END(str); if (single_byte_optimizable(str)) { while (s < send) { unsigned int c = *(unsigned char*)s; if (rb_enc_isascii(c, enc) && 'a' <= c && c <= 'z') { *s = 'A' + (c - 'a'); modify = 1; } s++; } } else { int ascompat = rb_enc_asciicompat(enc); while (s < send) { unsigned int c; if (ascompat && (c = *(unsigned char*)s) < 0x80) { if (rb_enc_isascii(c, enc) && 'a' <= c && c <= 'z') { *s = 'A' + (c - 'a'); modify = 1; } s++; } else { c = rb_enc_codepoint_len(s, send, &n, enc); if (rb_enc_islower(c, enc)) { /* assuming toupper returns codepoint with same size */ rb_enc_mbcput(rb_enc_toupper(c, enc), s, enc); modify = 1; } s += n; } } } if (modify) return str; return Qnil; }
Iterates through successive values, starting at str and ending at
other_str inclusive, passing each value in turn to the block. The
String#succ
method is used to generate each value. If
optional second argument exclusive is omitted or is false, the last value
will be included; otherwise it will be excluded.
If no block is given, an enumerator is returned instead.
"a8".upto("b6") {|s| print s, ' ' } for s in "a8".."b6" print s, ' ' end
produces:
a8 a9 b0 b1 b2 b3 b4 b5 b6 a8 a9 b0 b1 b2 b3 b4 b5 b6
If str and other_str contains only ascii numeric characters, both are recognized as decimal numbers. In addition, the width of string (e.g. leading zeros) is handled appropriately.
"9".upto("11").to_a #=> ["9", "10", "11"] "25".upto("5").to_a #=> [] "07".upto("11").to_a #=> ["07", "08", "09", "10", "11"]
static VALUE rb_str_upto(int argc, VALUE *argv, VALUE beg) { VALUE end, exclusive; VALUE current, after_end; ID succ; int n, excl, ascii; rb_encoding *enc; rb_scan_args(argc, argv, "11", &end, &exclusive); RETURN_ENUMERATOR(beg, argc, argv); excl = RTEST(exclusive); CONST_ID(succ, "succ"); StringValue(end); enc = rb_enc_check(beg, end); ascii = (is_ascii_string(beg) && is_ascii_string(end)); /* single character */ if (RSTRING_LEN(beg) == 1 && RSTRING_LEN(end) == 1 && ascii) { char c = RSTRING_PTR(beg)[0]; char e = RSTRING_PTR(end)[0]; if (c > e || (excl && c == e)) return beg; for (;;) { rb_yield(rb_enc_str_new(&c, 1, enc)); if (!excl && c == e) break; c++; if (excl && c == e) break; } return beg; } /* both edges are all digits */ if (ascii && ISDIGIT(RSTRING_PTR(beg)[0]) && ISDIGIT(RSTRING_PTR(end)[0])) { char *s, *send; VALUE b, e; int width; s = RSTRING_PTR(beg); send = RSTRING_END(beg); width = rb_long2int(send - s); while (s < send) { if (!ISDIGIT(*s)) goto no_digits; s++; } s = RSTRING_PTR(end); send = RSTRING_END(end); while (s < send) { if (!ISDIGIT(*s)) goto no_digits; s++; } b = rb_str_to_inum(beg, 10, FALSE); e = rb_str_to_inum(end, 10, FALSE); if (FIXNUM_P(b) && FIXNUM_P(e)) { long bi = FIX2LONG(b); long ei = FIX2LONG(e); rb_encoding *usascii = rb_usascii_encoding(); while (bi <= ei) { if (excl && bi == ei) break; rb_yield(rb_enc_sprintf(usascii, "%.*ld", width, bi)); bi++; } } else { ID op = excl ? '<' : rb_intern("<="); VALUE args[2], fmt = rb_obj_freeze(rb_usascii_str_new_cstr("%.*d")); args[0] = INT2FIX(width); while (rb_funcall(b, op, 1, e)) { args[1] = b; rb_yield(rb_str_format(numberof(args), args, fmt)); b = rb_funcall(b, succ, 0, 0); } } return beg; } /* normal case */ no_digits: n = rb_str_cmp(beg, end); if (n > 0 || (excl && n == 0)) return beg; after_end = rb_funcall(end, succ, 0, 0); current = rb_str_dup(beg); while (!rb_str_equal(current, after_end)) { VALUE next = Qnil; if (excl || !rb_str_equal(current, end)) next = rb_funcall(current, succ, 0, 0); rb_yield(current); if (NIL_P(next)) break; current = next; StringValue(current); if (excl && rb_str_equal(current, end)) break; if (RSTRING_LEN(current) > RSTRING_LEN(end) || RSTRING_LEN(current) == 0) break; } return beg; }
Returns true for a string which encoded correctly.
"\xc2\xa1".force_encoding("UTF-8").valid_encoding? #=> true "\xc2".force_encoding("UTF-8").valid_encoding? #=> false "\x80".force_encoding("UTF-8").valid_encoding? #=> false
static VALUE rb_str_valid_encoding_p(VALUE str) { int cr = rb_enc_str_coderange(str); return cr == ENC_CODERANGE_BROKEN ? Qfalse : Qtrue; }