How old is that file?

(Traditional format)

Tue Nov 2 16:16:41 2004 How old is that file?
Posted by Tony Lawrence
Search Keys: shell

Sometimes you want to know the age of a file. Perl has a "-M" test that gives you age in days, but this customer needed it in minutes. That's easy:

#!/usr/bin/perl
# howold.pl
$file=shift @ARGV;
@stat=stat $file;
$now=time();
$mtime=sprintf("%d",($now -$stat[10])/60);
# That's inode change time, stat[9] would be modification, and 8 is access
print "$mtime\n";
 

You'd use this in a script like this:

OLD=`howold.pl myfile`
if [ "$OLD" -gt 20 ]
then
  echo "older than 20 minutes"
else
  echo "Younger"
fi
 

You could put the whole script on one line:

printf("%d\n",(time() - (stat(@ARGV[0]))[10] )/60);
 

but that's much harder to follow and a lot easier to screw up.

Got something to add? Send me email.

More Articles by Tony Lawrence

Find me on Google+

© 2012-06-17 Tony Lawrence

---

Printer Friendly Version

Site map     |      Disclaimer

How old is that file? Copyright © November 2004 Tony Lawrence

Have you tried Searching this site?

Support Rates

This is a Unix/Linux resource website. It contains technical articles about Unix, Linux and general computing related subjects, opinion, news, help files, how-to's, tutorials and more.

Contact us

Printer Friendly Version