Re: grep: show matching line from pattern file

[Will Mengarini <seldon@eskimo.com>]

* Greg Wooledge <greg@wooledge.org> [22-05/28=Sa 17:11 -0400]:
> [...] 
> #!/usr/bin/perl
> use strict; use warnings;
> [...] 
> open PATS, "<patterns.txt" || die "can't open patterns.txt";
> [...] 

You need "or die", not "|| die", because of precedence: what you coded
checks whether "<patterns.txt" is logically true (it is), whereas you
wanted to check whether the result of open() is logically true.

In this transcript, the number before the prompt-ending '$' is $?:
--------------------------------
debian/pts/4 bash3 ~ 14:56 0$perl -e 'open "gweeblefleep" || die'
debian/pts/4 bash3 ~ 14:57 0$perl -e 'open "gweeblefleep" or die'
Died at -e line 1.
debian/pts/4 bash3 ~ 14:57 2$
--------------------------------

-- 
                 Will Mengarini  <seldon@eskimo.com>
                perl -le"print unpack '%C*',MENGARINI"