> I am touching files at the beginning and the ending of a simple shell
> script for gathering the running time of the script.
You really want to get acquaintated with command time. Your method is
not only laborous but also lacking useful information. Real time is
not usually not interesting but CPU time is.
$ time ls /etc/apache
conf conf.orig.tgz httpd.conf mime.types perl
conf.orig-perl.tgz cron.conf logformats modules startup.pl
use strict; print "Just Another Perl Hacker\n"; http://www.iki.fi/hauva/ #
"Father, I have done questionable things." - Roy