This is the sequel of Check links programmatically (with Perl)

This time, I use HTTP::Simple

Rewrite with HTTP::Simple

I restarted from my previous simple code that was using <> (read file on command line or get input from |, split it by carriage return).

It's a loop, that get a link and prints "✓" or "✗" depending the status of the link.

HTTP::Simple provides almost the same API than LWP::Simple with slightly different behaviour and some extends.

So except the use HTTP::Simple and the usage of a surrounding eval, this is the same code.

(if something is unclear in the following code, check previous blog post)

#!/usr/bin/env perl

use open ':std', ':encoding(UTF-8)';
use Term::ANSIColor;
use HTTP::Simple;

$| = 1;

while(<>) {
    chomp;
    my $link = $_;
    print "Checking [$link]...";
    eval { get($link) };
    if($@) {
            print color('red') . " \x{2717}\n" . color('reset');
    } else {
            print color('green') . " \x{2713}\n" . color('reset');
    }
}

Exceptions and status

Interesting enough, with HTTP::Simple, some functions are throwing exceptions. Read carefully the doc since some are throwing exceptions for connections and HTTP errors (like get) when others only for connections errors (like getprint)

Actually with this get method I can't retrieve easily the status. I could have printed the exception, but it also gives the line number where the exception occured and it is not very pretty.

I can get the status from getprint or getstore. Since I don't need to print nor store anything, it's a bit overkill, but I can probably handle this 😃. So I tried to use getstore($link, "/dev/null") but it was not well accepted 😁

My trick is then to use getprint and trash output using select. Here is the idea:

my $TRASH;
open($TRASH, '>', '/dev/null');

# Later in code
select $TRASH;
print "Trashed\n";
select STDOUT;

Final code

Below are all the final code snippets.

The links are stored in a file, one per line:

http://cpantesters.org
https://img.shields.io/badge/Language-Perl-blue
https://www.perltutorial.org/
http://stratopan.com
https://www.perl.org/

Beside I have my checklinks.pl:

#!/usr/bin/env perl

use open ':std', ':encoding(UTF-8)';
use Term::ANSIColor;
use HTTP::Simple;

my $TRASH;
open($TRASH, '>', '/dev/null');

$| = 1;

while(<>) {
    chomp;
    my $link = $_;
    print "Checking [$link]...";

    select $TRASH;
    my $status = getprint($link);
    select STDOUT;
    if(! is_success($status)) {
            print color('red') . " \x{2717} --> $status\n" . color('reset');
    } else {
            print color('green') . " \x{2713}\n" . color('reset');
    }
}

Then I execute my link checker through a pipe:

$ cat links.txt | perl checklinks.pl

And I get my pretty links checker report: