Excerpt from & copyright by Perl documentation:
- stat FILEHANDLE
- stat EXPR
- stat
Returns a 13-element list giving the status info for a file, either the file opened via FILEHANDLE, or named by EXPR. If EXPR is omitted, it stats $_ . Returns a null list if the stat fails. Typically used as follows:
($dev,$ino,$mode,$nlink,$uid,$gid,$rdev,$size,
$atime,$mtime,$ctime,$blksize,$blocks)
= stat($filename)
Not all fields are supported on all filesystem types. Here are the meanings of the fields:
0 dev device number of filesystem
1 ino inode number
2 mode file mode (type and permissions)
3 nlink number of (hard) links to the file
4 uid numeric user ID of file's owner
5 gid numeric group ID of file's owner
6 rdev the device identifier (special files only)
7 size total size of file, in bytes
8 atime last access time in seconds since the epoch
9 mtime last modify time in seconds since the epoch
10 ctime inode change time in seconds since the epoch (*)
11 blksize preferred block size for file system I/O
12 blocks actual number of blocks allocated
This is by no means complete. See stat for further information.
| [reply]
[d/l]
[select] |
How can the atime , mtime and ctime be changed from Perl?
Well of course, you would change a file's atime (to "now") by opening it for read access and reading some data from it; to change the mtime (to "now") you'd have to open for write access and then actually modify its contents somehow (i.e. actually write something to it). The only way I can imagine to set ctime (to "now") is to delete the file and then (re)create it.
There's a unix shell command called "touch" that allows a bit more flexibility: it can be used to set atime and/or mtime -- either to "now" or to a specified date/time (but setting things to a future date might be a bad idea). The man page for "touch" doesn't say anything about altering the ctime of a file. | [reply] |
Note that the ctime of a file can't be changed to anything other than the current time.
Dave. | [reply] |
Oops. I thought it said 'mtime' up there (rather than 'ctime', as I see now).
I think that's OS-dependent, somewhat. On Mac OS X, I was able to change the mtime of a file. I wouldn't be surprised if some systems require administrative access (or just file ownership), but I haven't tested anywhere else.
Update: I tried it on Debian GNU/Linux too, and it works the same way.
$ touch testme
$ ls -l testme
-rw-r--r-- 1 kyle kyle 0 2007-02-04 13:12 testme
$ perl -e 'utime time,1111111111,"testme";'
$ ls -l testme
-rw-r--r-- 1 kyle kyle 0 2005-03-17 19:58 testme
$
| [reply]
[d/l] |
there is no perl builtin for these purposes. use the POSIX funtions instead.
man 2 utime ;) | [reply] |
| [reply] |