FFmpeg  4.0
file_open.c
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1 /*
2  * This file is part of FFmpeg.
3  *
4  * FFmpeg is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU Lesser General Public
6  * License as published by the Free Software Foundation; either
7  * version 2.1 of the License, or (at your option) any later version.
8  *
9  * FFmpeg is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12  * Lesser General Public License for more details.
13  *
14  * You should have received a copy of the GNU Lesser General Public
15  * License along with FFmpeg; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17  */
18 
19 #include "config.h"
20 #include "internal.h"
21 #include "mem.h"
22 #include <stdarg.h>
23 #include <fcntl.h>
24 #include <sys/stat.h>
25 #if HAVE_UNISTD_H
26 #include <unistd.h>
27 #endif
28 #if HAVE_IO_H
29 #include <io.h>
30 #endif
31 
32 #ifdef _WIN32
33 #undef open
34 #undef lseek
35 #undef stat
36 #undef fstat
37 #include <windows.h>
38 #include <share.h>
39 #include <errno.h>
40 #include "wchar_filename.h"
41 
42 static int win32_open(const char *filename_utf8, int oflag, int pmode)
43 {
44  int fd;
45  wchar_t *filename_w;
46 
47  /* convert UTF-8 to wide chars */
48  if (utf8towchar(filename_utf8, &filename_w))
49  return -1;
50  if (!filename_w)
51  goto fallback;
52 
53  fd = _wsopen(filename_w, oflag, SH_DENYNO, pmode);
54  av_freep(&filename_w);
55 
56  if (fd != -1 || (oflag & O_CREAT))
57  return fd;
58 
59 fallback:
60  /* filename may be in CP_ACP */
61  return _sopen(filename_utf8, oflag, SH_DENYNO, pmode);
62 }
63 #define open win32_open
64 #endif
65 
66 int avpriv_open(const char *filename, int flags, ...)
67 {
68  int fd;
69  unsigned int mode = 0;
70  va_list ap;
71 
72  va_start(ap, flags);
73  if (flags & O_CREAT)
74  mode = va_arg(ap, unsigned int);
75  va_end(ap);
76 
77 #ifdef O_CLOEXEC
78  flags |= O_CLOEXEC;
79 #endif
80 #ifdef O_NOINHERIT
81  flags |= O_NOINHERIT;
82 #endif
83 
84  fd = open(filename, flags, mode);
85 #if HAVE_FCNTL
86  if (fd != -1) {
87  if (fcntl(fd, F_SETFD, FD_CLOEXEC) == -1)
88  av_log(NULL, AV_LOG_DEBUG, "Failed to set close on exec\n");
89  }
90 #endif
91 
92  return fd;
93 }
94 
95 typedef struct FileLogContext {
96  const AVClass *class;
97  int log_offset;
98  void *log_ctx;
100 
101 static const AVClass file_log_ctx_class = {
102  .class_name = "TEMPFILE",
103  .item_name = av_default_item_name,
104  .option = NULL,
105  .version = LIBAVUTIL_VERSION_INT,
106  .log_level_offset_offset = offsetof(FileLogContext, log_offset),
107  .parent_log_context_offset = offsetof(FileLogContext, log_ctx),
108 };
109 
110 int avpriv_tempfile(const char *prefix, char **filename, int log_offset, void *log_ctx)
111 {
112  FileLogContext file_log_ctx = { &file_log_ctx_class, log_offset, log_ctx };
113  int fd = -1;
114 #if !HAVE_MKSTEMP
115  void *ptr= tempnam(NULL, prefix);
116  if(!ptr)
117  ptr= tempnam(".", prefix);
118  *filename = av_strdup(ptr);
119 #undef free
120  free(ptr);
121 #else
122  size_t len = strlen(prefix) + 12; /* room for "/tmp/" and "XXXXXX\0" */
123  *filename = av_malloc(len);
124 #endif
125  /* -----common section-----*/
126  if (!*filename) {
127  av_log(&file_log_ctx, AV_LOG_ERROR, "ff_tempfile: Cannot allocate file name\n");
128  return AVERROR(ENOMEM);
129  }
130 #if !HAVE_MKSTEMP
131 # ifndef O_BINARY
132 # define O_BINARY 0
133 # endif
134 # ifndef O_EXCL
135 # define O_EXCL 0
136 # endif
137  fd = open(*filename, O_RDWR | O_BINARY | O_CREAT | O_EXCL, 0600);
138 #else
139  snprintf(*filename, len, "/tmp/%sXXXXXX", prefix);
140  fd = mkstemp(*filename);
141 #if defined(_WIN32) || defined (__ANDROID__)
142  if (fd < 0) {
143  snprintf(*filename, len, "./%sXXXXXX", prefix);
144  fd = mkstemp(*filename);
145  }
146 #endif
147 #endif
148  /* -----common section-----*/
149  if (fd < 0) {
150  int err = AVERROR(errno);
151  av_log(&file_log_ctx, AV_LOG_ERROR, "ff_tempfile: Cannot open temporary file %s\n", *filename);
152  av_freep(filename);
153  return err;
154  }
155  return fd; /* success */
156 }
157 
158 FILE *av_fopen_utf8(const char *path, const char *mode)
159 {
160  int fd;
161  int access;
162  const char *m = mode;
163 
164  switch (*m++) {
165  case 'r': access = O_RDONLY; break;
166  case 'w': access = O_CREAT|O_WRONLY|O_TRUNC; break;
167  case 'a': access = O_CREAT|O_WRONLY|O_APPEND; break;
168  default :
169  errno = EINVAL;
170  return NULL;
171  }
172  while (*m) {
173  if (*m == '+') {
174  access &= ~(O_RDONLY | O_WRONLY);
175  access |= O_RDWR;
176  } else if (*m == 'b') {
177 #ifdef O_BINARY
178  access |= O_BINARY;
179 #endif
180  } else if (*m) {
181  errno = EINVAL;
182  return NULL;
183  }
184  m++;
185  }
186  fd = avpriv_open(path, access, 0666);
187  if (fd == -1)
188  return NULL;
189  return fdopen(fd, mode);
190 }
#define NULL
Definition: coverity.c:32
#define LIBAVUTIL_VERSION_INT
Definition: version.h:85
Memory handling functions.
#define O_BINARY
FILE * av_fopen_utf8(const char *path, const char *mode)
Open a file using a UTF-8 filename.
Definition: file_open.c:158
const char * av_default_item_name(void *ptr)
Return the context name.
Definition: log.c:191
int avpriv_tempfile(const char *prefix, char **filename, int log_offset, void *log_ctx)
Wrapper to work around the lack of mkstemp() on mingw.
Definition: file_open.c:110
const char * class_name
The name of the class; usually it is the same name as the context structure type to which the AVClass...
Definition: log.h:72
#define av_malloc(s)
int avpriv_open(const char *filename, int flags,...)
A wrapper for open() setting O_CLOEXEC.
Definition: file_open.c:66
static int flags
Definition: log.c:55
#define av_log(a,...)
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
#define AVERROR(e)
Definition: error.h:43
#define AV_LOG_DEBUG
Stuff which is only useful for libav* developers.
Definition: log.h:197
common internal API header
int log_offset
Definition: file.c:40
char * av_strdup(const char *s)
Duplicate a string.
Definition: mem.c:251
#define O_EXCL
static const AVClass file_log_ctx_class
Definition: file_open.c:101
Describe the class of an AVClass context structure.
Definition: log.h:67
void * log_ctx
Definition: file.c:41
#define snprintf
Definition: snprintf.h:34
int len
#define av_freep(p)
mode
Use these values in ebur128_init (or&#39;ed).
Definition: ebur128.h:83