examples

perl.pl

use strict;
use warnings;


local $/; # set slurp mode so that entire file is read at once (instead of a single line)

my $content = <STDIN>;

my %refs = ();
foreach my $key ($content =~ m/\\ref\{([\w_]+)\}/g) {
    $refs{$key} = 1;
}

my %labels = ();
foreach my $key ($content =~ m/\\label\{([\w_]+)\}/g) {
    $labels{$key} = 1;
}

foreach my $ref (keys %refs) {
    if (!$labels{$ref}) {
        print "oops, dangling ref: $ref\n";
    }
}

foreach my $label (keys %labels) {
    if (!$refs{$label}) {
        print "oops, dangling label: $label\n";
    }
}

print "\n";

shell.sh

#!/bin/bash

echo $@  # all args passed in

for name in $@
    do
        echo $name
        cat $name | perl checkref.pl
    done