[root@devel3 log]# cat /usr/bin/re
#!/usr/bin/perl
die "
  Usage re [RE] <optional filename/dirname>
    Full Perl grep on STDIN or filename
    Recursive if filename is a dir
" unless @ARGV >= 1;

my $re = qr/$ARGV[0]/;
if ( $ARGV[1] ) {
    if ( -d $ARGV[1] ) {
        # we have a dir so let's recuse
        require File::Find;
        File::Find::find( \&grep_file, $ARGV[1] );
    }
    else {
        open F, $ARGV[1] or die "Can't read $ARGV[1] $!\n";
        do{print if m/$re/} while <F>;
        close F;
    }
}
else {
    do{print if m/$re/} while <STDIN>;
}

sub grep_file {
  return unless -f $_;
    open F, $_ or die "Can't read $File::Find::name $!\n";
    my $matches = '';
    do{$matches .= $_ if m/$re/} while <F>;
    print "$File::Find::name\n$matches" if $matches;
    close F;
}

[root@devel3 log]# re pri.. /usr/bin/re
        do{print if m/$re/} while <F>;
    do{print if m/$re/} while <STDIN>;
    print "$File::Find::name\n$matches" if $matches;

[root@devel3 log]# cat /usr/bin/re | re [A-Z]+IN
    Full Perl grep on STDIN or filename
    do{print if m/$re/} while <STDIN>;

[root@devel3 log]# cat /usr/bin/re | re "\b[A-Z]+\b"
  Usage re [RE] <optional filename/dirname>
    Full Perl grep on STDIN or filename
" unless @ARGV >= 1;
my $re = qr/$ARGV[0]/;
if ( $ARGV[1] ) {
[snip]

[root@devel3 log]# re perl /devel/www/modperl
/devel/www/modperl/logout.pl
#!/usr/bin/perl -w
/devel/www/modperl/search.pl
#!/usr/bin/perl -w
/devel/www/modperl/error.pl
#!/usr/bin/perl -w
[snip]

[root@devel3 log]#