CODEWITHSUNDEEP
perlfiletime

Reputation:

How can I compare file creation time to the current time in Perl?

i want to compare the current time and file creation time in Perl but both are in different format. localtime is in this format:

22116291110813630

and file creation time is 

Today, December 29, 2008, 2:38:37 PM

How do i compare which one is greater and their difference?

Upvotes: 5

Views: 25292

Answers (4)

jimtut
jimtut

Reputation: 2393

It's even easier than using stat() and time()/localtime().

my $diff = -M $filename;

The -M operator returns the "age" of the file (in days since the start of the program). It's documented under the -X functions or in perldoc -f -X.

Upvotes: 16

Mike Mestnik
Mike Mestnik

Reputation: 323

These two functions are thanks to jimtut's answer. fileage prints the number of seconds as an integer, perfect for usage in a shell, of a file from when it was created. fileage is the answer to the above question, while dataage prints the same for the contents of a file as that's the answer I was looking for I'm sure these will both be useful.

function fileage {
  perl -e 'printf "%i\n", 60 * 60 * 24 * -C "'"${1:?Must provide a file name}"'"'
}

function dataage {
  perl -e 'printf "%i\n", 60 * 60 * 24 * -M "'"${1:?Must provide a file name}"'"'
}

Upvotes: 0

Nathan Fellman
Nathan Fellman

Reputation: 127628

If you want to compare values, you might want to use the number you got from localtime in scalar context and the inode change time that you can get from stat:

               ($dev,$ino,$mode,$nlink,$uid,$gid,$rdev,$size,
                  $atime,$mtime,$ctime,$blksize,$blocks)
                      = stat($filename);

where:

                 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

So you want field 9:


$mtime = ( stat $filename )[9];
$current_time = time;

$diff = $current_time - $mtime;

Upvotes: 14

ysth
ysth

Reputation: 98508

localtime returns a list of values in list context. See the localtime documentation or perlcheat. In your example, it looks like those all mushed together. In scalar context, it returns a formatted string like Mon Dec 29 03:16:33 2008. On most platforms, the file inode change time will be returned from stat as a number of seconds since some epoch. You should be able to directly compare that to the result of time() (not localtime()).

Upvotes: 3

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