| file.info {base} | R Documentation |
Utility function to extract information about files on the user's file systems.
file.info(..., extra_cols = TRUE) file.mode(...) file.mtime(...) file.size(...)
... |
character vectors containing file paths. Tilde-expansion
is done: see |
extra_cols |
Logical: return all cols rather than just the first six. |
What constitutes a ‘file’ is OS-dependent but includes
directories. (However, directory names must not include a trailing
backslash or slash on Windows.) See also the section in the help for
file.exists on case-insensitive file systems.
The file ‘mode’ follows POSIX conventions, giving three octal digits summarizing the permissions for the file owner, the owner's group and for anyone respectively. Each digit is the logical or of read (4), write (2) and execute/search (1) permissions.
On most systems symbolic links are followed, so information is given about the file to which the link points rather than about the link.
For file.info, data frame with row names the file names and columns
size |
double: File size in bytes. |
isdir |
logical: Is the file a directory? |
mode |
integer of class |
mtime, ctime, atime |
integer of class |
uid |
integer: the user ID of the file's owner. |
gid |
integer: the group ID of the file's group. |
uname |
character: |
grname |
character: |
Unknown user and group names will be NA.
If extra_cols is false, only the first six columns are
returned: as these can all be found from a single C system call this
can be faster. (However, properly configured systems will use a
‘name service cache daemon’ to speed up the name lookups.)
Entries for non-existent or non-readable files will be NA.
The uid, gid, uname and grname columns
may not be supplied on a non-POSIX Unix-alike system, and will not be
on Windows.
What is meant by the three file times depends on the OS and file
system. On Windows native file systems ctime is the file
creation time (something which is not recorded on most Unix-alike file
systems). What is meant by ‘file access’ and hence the
‘last access time’ is system-dependent.
The times are reported to an accuracy of seconds, and perhaps more on some systems. However, many file systems only record times in seconds, and some (e.g., modification time on FAT systems) are recorded in increments of 2 or more seconds.
file.mode, file.mtime and file.size are
convenience wrappers returning just one of the columns.
Some systems allow files of more than 2Gb to be created but
not accessed by the stat system call. Such files will show up
as non-readable (and very likely not be readable by any of R's input
functions) – fortunately such file systems are becoming rare.
Sys.readlink to find out about symbolic links,
files, file.access,
list.files,
and DateTimeClasses for the date formats.
Sys.chmod to change permissions.
ncol(finf <- file.info(dir())) # at least six
finf # the whole list
## Those that are more than 100 days old :
finf <- file.info(dir(), extra_cols = FALSE)
finf[difftime(Sys.time(), finf[,"mtime"], units = "days") > 100 , 1:4]
file.info("no-such-file-exists")