Tag Archives: terminal

The utility of a scripting language.

I feel like quite a geek. I had some text copied from my IRC client that I wanted to transform to XML for my XSLT sheet to display all nicely on the Web interface. Format of a line copied from the client:

altered nickname<tab><tab>message<tab>hh:mm:ss<space><AM or PM><carriage return>

Correctly formatted XML for the XSLT sheet:

<message><time>unix timestamp</time></time><type>2</type><sender>correct nickname</sender><content>message</content></message>

How to transform this? I could’ve done the majority of the work with a PCRE regexp and search/replace, but that wouldn’t have fixed the nicknames (since you can’t make if/else decisions in a replace in most editors) or calculated the correct UNIX timestamps. So I turned to scripting, of course. Some would have chosen to use Ruby, others Python, or Perl, or possibly even bash for some masochistic reason. I chose PHP.

Took five minutes, most of which was spent constructing the regexp. The code:

<?php

$conversation = file_get_contents(__FILE__, false, NULL, __COMPILER_HALT_OFFSET__);
$valid_nicks = "nick1|nick2|nick3|nick4|nick5";
preg_match_all('/^('.$valid_nicks.')(?:\t+)(&#91;^\n\t&#93;+)(?:\t+)(\d+):(\d+):(\d+)&#91; &#93;(&#91;AP&#93;M)$/mSu', $conversation, $matches, PREG_SET_ORDER);
$xml = "";
$time = time();
foreach ($matches as $splitline) {
    $nick = $splitline&#91;1&#93;;
    $message = $splitline&#91;2&#93;;
    $hour = $splitline&#91;3&#93;;
    $minute = $splitline&#91;4&#93;;
    $second = $splitline&#91;5&#93;;
    $meridian = $splitline&#91;6&#93;;
    if ($nick === 'nick1' || $nick === 'nick2') {
        $nick = 'real_nick1and2';
    } else if ($nick === 'nick3' || $nick === 'nick4') {
        $nick = 'real_nick3and4';
    }
    ++$time; //mktime($hour + ($meridian === 'PM' ? 12 : 0), $minute, $second, date('n'), $meridian === 'PM' ? 1 : 2, date('Y')));
    $xml .= "<message><time>{$time}</time><type>2</type><sender>{$nick}</sender><content>{$message}</content></message>\n";
}

echo $xml;

__halt_compiler();
// the conversation was pasted here

I daresay that was a pretty cheaply elegant bit of work, if I may be allowed to pat myself on the back. Entirely trivial stuff, but it shows how useful scripting can be for some tasks. How inane would that conversion have been, replacing the nicks by hand and calculating the timestamps one at a time? The conversation was about 500 lines long. Yay scripting.

Please, don’t comment with a one line Perl script to do the same thing from STDIN, I’m well aware you can use Perl to compress any complexity down to what looks like a couple hundred bps of line noise :-D.

P.S.: I am fully aware that the code has several inefficiencies, odd-seeming decisions, things that could’ve been done better, and so on, and so on. Who cares? It works. It’s not meant to win design awards.

Terminal coloring

Ah, the wonderful world of the command line. I wouldn’t be able to look at myself in the mirror (and by mirror, I mean reflection in my monitor) if I couldn’t play the shell as if it were a finely tuned 128-key instrument. But I like to add a little pizzaz to the very black-and-white (or black-and-amber, or black-and-green) world of Terminal.

To do this, one adds ANSI color codes to things. Pass a proper flag or two to ls, set CLICOLOR in your environment, and most of all, set your PS1 to something interesting. Here’s mine for my local machine:

PS1='\[\033[35m\]\u@\h\[\033[00m\]:\[\033[94m\]\w\[\033[96m\]\$\[\033[00m\] '

The result looks something like this:

gwynne@localhost:~/Desktop$ _
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