Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!wuarchive!usc!elroy.jpl.nasa.gov!jpl-devvax!lwall
From: lwall@jpl-devvax.JPL.NASA.GOV (Larry Wall)
Newsgroups: comp.unix.questions
Subject: Re: how to compare file modification time in bourne shell script
Message-ID: <8855@jpl-devvax.JPL.NASA.GOV>
Date: 24 Jul 90 20:24:04 GMT
References: <1990Jul23.233044.2729@silma.com>
Reply-To: lwall@jpl-devvax.JPL.NASA.GOV (Larry Wall)
Organization: Jet Propulsion Laboratory, Pasadena, CA
Lines: 28

In article <1990Jul23.233044.2729@silma.com> aab@silma.UUCP () writes:
: 
: I need to compare the modification times of two files in a bourne shell
: script. I would like to do this without writing C code.
: Machine is Sparcstation 1 running SunOS 4.03c
: 
: Thus I need a function:
: 
: newer file1 file2
: 
: that returns 0 if file1 is newer than file2 else returns 1
: 
: Can it be done?

Several ways.

[ X`find file2 -newer file1 -print` = X ]

perl -e 'exit ((stat("file1"))[9] < (stat("file2"))[9])'

ls -lt file1 file2 | tail -1 | grep file2 >/dev/null

All of these should work on a Sun.  Some machines may not have a -newer
option to find or a grep that returns a reasonable status.  Some really
primitive machines don't have Perl.  :-)

Larry Wall
lwall@jpl-devvax.jpl.nasa.gov