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From: chrisb@risky.Convergent.COM (Chris Bertin)
Newsgroups: comp.unix.questions,alt.sources.d
Subject: Re: how to compare file modification time  (whole dir tree?)
Message-ID: <303@risky.Convergent.COM>
Date: 6 Aug 90 16:54:44 GMT
References: <1990Jul27.153223.12416@chinet.chi.il.us> <1446@chinacat.Unicom.COM> <1990Aug3.155651.12006@sq.sq.com>
Organization: Convergent Technologies, San Jose, CA
Lines: 49

In article <1990Aug3.155651.12006@sq.sq.com>, lee@sq.sq.com (Liam R. E. Quin) writes:
> fritz@mercury.caltech.edu (Fritz Nordby) writes:
> > Am I missing something here, or will the following [work]?
> >
> >#!/bin/sh
> >case $# in 2);;*)echo "usage: ${0:-newer} file1 file2" >&2;exit 2;;esac
> >[ ! -f "$2" -o -f "$1" -a "X`/bin/ls -t \"\$1\" \"\$2\"`" = "X$1
> >$2"] >/dev/null 2>&1
> 
> I have no idea.  It *might* have won the Obfuscated Shell Contest, except
> that there isn't one.  At first I thought it was a perl script.
> I have had a go at expanding this a little below... 
....
> Lee

Expanded doesn't mean better.
> 
> # valilidate arguments:
> case $# in
> 2)  ;;
> *)  echo "usage: ${0:-newer} file1 file2" >&2
>     exit 2
>     ;;
> esac

The comment is useless and 'valilidate' is a new word to me. It is obviously
an argument validation check, since it is checking $# and echo-ing a usage
statement.

> 
> test x"${LsOutput}" = x"${FirstNewer}
> exit $?
> 

The 'exit' statement is useless. 'test' will return the right exit code.

To go back to the original script, it really doesn't need to open /dev/null.
Most people do that when they want to discard output, but why not close
the apropriate file descriptor?
> >[ ! -f "$2" -o -f "$1" -a "X`/bin/ls -t \"\$1\" \"\$2\"`" = "X$1
> >$2"] >/dev/null 2>&1

[ ! -f "$2" -o -f "$1" -a "X`/bin/ls -t \"\$1\" \"\$2\"`" = "X$1 $2"] >&- 2>&-

Chris
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