How do I get a file's last modified time in Perl? - perl

Question

Suppose I have a filehandle $fh. I can check its existence with -e $fh or its file size with -s $fh or a slew of additional information about the file. How can I get its last modified time stamp?

Answer 1

Calling the built-in function stat($fh) returns an array with the following information about the file handle passed in (from the perlfunc man page for stat):
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 since the epoch
9 mtime last modify time since the epoch
10 ctime inode change time (NOT creation time!) since the epoch
11 blksize preferred block size for file system I/O
12 blocks actual number of blocks allocated
Element number 9 in this array will give you the last modified time since the epoch (00:00 January 1, 1970 GMT). From that you can determine the local time:
my $epoch_timestamp = (stat($fh))[9];
my $timestamp = localtime($epoch_timestamp);
Alternatively, you can use the built-in module File::stat (included as of Perl 5.004) for a more object-oriented interface.
And to avoid the magic number 9 needed in the previous example, additionally use Time::localtime, another built-in module (also included as of Perl 5.004). Together these lead to some (arguably) more legible code:
use File::stat;
use Time::localtime;
my $timestamp = ctime(stat($fh)->mtime);

Answer 2

Use the builtin stat function. Or more specifically:
my $modtime = (stat($fh))[9]

Answer 3

my #array = stat($filehandle);
The modification time is stored in Unix format in $array[9].
Or explicitly:
my ($dev, $ino, $mode, $nlink, $uid, $gid, $rdev, $size,
$atime, $mtime, $ctime, $blksize, $blocks) = stat($filepath);
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
The epoch was at 00:00 January 1, 1970 GMT.
More information is in stat.

Answer 4

You need the stat call, and the file name:
my $last_mod_time = (stat ($file))[9];
Perl also has a different version:
my $last_mod_time = -M $file;
but that value is relative to when the program started. This is useful for things like sorting, but you probably want the first version.

Answer 5

If you're just comparing two files to see which is newer then -C should work:
if (-C "file1.txt" > -C "file2.txt") {
{
/* Update */
}
There's also -M, but I don't think it's what you want. Luckily, it's almost impossible to search for documentation on these file operators via Google.

Answer 6

You could use stat() or the File::Stat module.
perldoc -f stat

Answer 7

I think you're looking for the stat function (perldoc -f stat)
In particular, the item found at index 9 of the returned list (i.e., the 10th field) is the last modify time of the file, in seconds since the epoch.
So:
my $last_modified = (stat($fh))[9];

Answer 8

On my FreeBSD system, stat just returns a bless.
$VAR1 = bless( [
102,
8,
33188,
1,
0,
0,
661,
276,
1372816636,
1372755222,
1372755233,
32768,
8
], 'File::stat' );
You need to extract mtime like this:
my #ABC = (stat($my_file));
print "-----------$ABC['File::stat'][9] ------------------------\n";
or
print "-----------$ABC[0][9] ------------------------\n";

Answer 9

This is very old thread, but I tried using the solution and could not get the information out of File::stat. (Perl 5.10.1)
I had to do the following:
my $f_stats = stat($fh);
my $timestamp_mod = localtime($f_stats->mtime);
print "MOD_TIME = $timestamp_mod \n";
Just thought I share in case anyone else had the same trouble.