#!/usr/bin/perl

die "usage: pipegrep pattern command files\n" unless @ARGV;

$debugging = 0;

$ARGV[0] eq '-i' && do { shift; $insensitiv = 1 };

if ($ARGV[0] eq '-l') {
        shift;
        $action = <<'EOF';
                print $file,"\n";
                next file;
EOF
} else {
        $action = <<'EOF';
                print $file,"\t:",$_;
EOF
}

# get the pattern an protect the delimiter we'll use.

$pat = shift;
$pat =~ s/!/\\!/g;

# get command and make shure it has a {}.

$cmd = shift;
$cmd .= ' {}' unless $cmd =~ /{}/;

# modify each filename into the corresponding command.

for (@ARGV) {
        $file = $_;
        $_ = $cmd;
        s/{}/$file/;
        s/$/ |/;
}

# generate the program.

$prog = <<EOF;
file: foreach \$file (\@ARGV) {
        open(FILE,\$file) || do {
                "Can't open \$file: \$!\\n";
                next;
        };
        while(<FILE>) {
EOF
if($insensitiv) { $prog .= <<EOH;
                if (m!$pat!i) {
EOH
} else { $prog .= <<EOG;
                if (m!$pat!) {
EOG
}
$prog .= <<EOT;
                        $action;
                }
        }
}
EOT
print $prog if $debugging;

# and finally, do it.

eval $prog;
die $@,"\n" if $@;