#!

Weather or not

mc — Sun, 15 May 2011 03:36:16 +0000

Ok, seriously. Can’t we master simple PHP classes like a sensible weather data retrieval library?

I’ve tried a few solutions but all of them suck due to poor documentation (PHP Weather I’m looking at you), jingoistic support for only USA airports (PHPWeatherLib) or being otherwise perfect but too simplistic (Google Weather API).

Herein lies a GitHub submission for a simple weather forecast wrapper around Weather Underground‘s beautifully simple API.
Its designed to be as simplistic as possible while still providing some handy functionality.
I’ll probably keep adding to its functionality as needed.

Documentation is provided inline (PHPDoc) as well as in the docs folder with fancy frames and such.

Simple bash variable security with OpenSSL

mc — Wed, 17 Nov 2010 05:25:10 +0000

Lets say you have a script that requires a number of variables to operate such as a database connection that requires a server, username and password. It’s usually a good idea to keep all this config in one place but dumping this in a plain text file is usually a bad idea.
The example below allows you to place application level config into a decently encrypted file and keep it all behind one master password.
To do all this we need two files. The first is obviously the encrypted variable config itself. The second is your script file which needs to decrypt the config file and perform whatever action is needed.

In this example I’m going to assume we are connecting to a remote database. Most protocols require three pieces of data to pull this off: a server, a username and a password. We are going to store these three pieces of data in a file called config.plain, encrypt this file (making config.aes), extract its variables and finally connect to our remote database.

I’m going to use the following example config.plain file:

^?Download config.plain

SERVER=FooBar
USER=JOE
PASS=RANDOM

So we need to encrypt our config.plain file and turn it into config.aes (AES being the encryption standard we are using). The following example is cheerfully swiped from the example given over at Tombuntu.

^?View Code BASH

>openssl aes-256-cbc -a -salt -in config.plain -out config.aes

So if we wanted to reverse this and decrypt the config.aes file on the command line we could run:

^?View Code BASH

>openssl aes-256-cbc -d -a -salt -in config.aes

NOTE: For some reason the OpenSSL CLI doesn’t obey the Unix standard of specifying ‘-’ as a file name to output to the console. Omitting the ‘-out’ argument will instead output to STDOUT.

Putting it all together

The config.plain example file:

^?Download config.plain

SERVER=FooBar
USER=JOE
PASS=RANDOM

The config.aes file (same as above but after encryption using the password ‘password’):

^?Download config.aes

U2FsdGVkX19aTdTnSuV1p5R6DCQxp21yrlCc+9j9dap/ziojbiDP1SbSM+6HXF0T
PabsGQgSdV8Ir4rmMjgyFA==

The actual script file which does the decryption and performs the final actions on the data.
We are going to accept the master password from the command line (so we would run the below as ‘script password’ – assuming our script was called ‘script’ and the password was ‘password’). This is not the most secure method available since you can see the launch method of all applications running on the system using ‘ps’. If you want more security I would instead store your password in a system variable and use that instead of reading from the command line. If you wish to do this you can simply strip out all the lines that do error checking and use ‘KEY’ as a system variable to store the master password.

^?Download script

#!/bin/bash
# USAGE: script 
# Do something with the associated config.aes script in a reasonably secure way
#
# Example config.plain content:
# SERVER=FooBar
# USER=JOE
# PASS=RANDOM
#
# Command to encrypt config.plain -> config.aes
# openssl aes-256-cbc -a -salt -in config.plain -out config.aes
 
# Do some housekeeping to check we launched with the requisite number of arguments
if [ "$#" -ne 1 ]; then
	echo "USAGE: $0 "
	exit 1
fi
KEY="$1"
 
# Import the variables from our decrypted stream
STREAM=`openssl aes-256-cbc -d -pass "pass:$KEY" -a -salt -in config.aes`
if [ "$?" -ne 0 ]; then
	echo "Invalid password specified to decrypt configuration file. Aborting."
	exit 1
fi
source <(echo "$STREAM")
 
# REPLACE THE STUFF BELOW THIS LINE WITH WHAT YOU WANT TO DO WITH YOUR SECURE VARIABLES
echo "Server: $SERVER"
echo "Username: $USER"
echo "Password: $PASS"

Last.FM submissions with Audacious

mc — Wed, 09 Jun 2010 00:35:10 +0000

Some time ago the good folks behind my favorite media player Audacious decided to abandon in-built support for Last.FM submissions.

The reasoning behind this seems to be that the Last.FM API was becoming a little too much to maintain which I suppose is fair enough in its quest to remain just a music player i.e. not a screen-hogging iTunes clone like so many others.

Heres how to put Last.FM support back into Audacity.

I’m going to assume you are a sensible person and using a Debian based system rather than Fedora. If you are one of these hat loving deviants, substitute ‘yum’ for apt-get below and feel free to voyage though the countless pains required to get Yum to actually do its job.

Installing LastFMSubmitD

I’m not sure on the capitalization of the daemon process LastFMSubmitD so that might be the wrong name entirely.

Anyway, first install pretty much the only component we need:

^?View Code BASH

apt-get install lastfmsubmitd

OPTIONAL – Set up the HTTP_PROXY

For some reason the daemon does not get proxy details right. This is easily fixed by opening /etc/init.d/lastfmsubmitd in your favorite editor and inserting the following line somewhere near the top (I put it after the ‘GROUP=’ line which should be the last bit of the daemon config area).
If you have no idea what a proxy is or why you should be doing this you can probably skip this section.

^?View Code BASH

export http_proxy="http://whatever.stupid.proxy.edu.au:8080/"

Parse Audacious output

Dump the following script somewhere you can find it. For this example I will use /home/user/bin/scrobble

^?Download scrobble

#!/bin/bash
if [ ! -x '/usr/lib/lastfmsubmitd/lastfmsubmit' ]; then
	echo "LastFMSubmitD does not appear to exist on this machine"
	echo "You can install it using Apt or Yum"
	exit 1
fi
if [ "$#" == 0 ]; then
	echo 'Usage: scrobble " - " ""'
	exit 1
fi
 
ARTIST=${1%% - *}
SONG=${1##* - }
LENGTH=$[ $2 / 1000 ]
echo "ARTIST = [$ARTIST]"
echo "SONG = [$SONG]"
echo "LENGTH = [$LENGTH]"
 
/usr/lib/lastfmsubmitd/lastfmsubmit --artist "$ARTIST" --title "$SONG" --length "$LENGTH"

Pointing Song Change at your script

First make sure you have the Song Change plugin enabled in Audacious first.

Now point the command Audacious is to run when starting a new song at the script in the following way:

/home/user/bin/scrobble "%s" "%l"

All done. Now any tracks played via Audacious will be passed to the script which will parse the incoming song title into a format that the LastFMSubmitD daemon can use.

Interactive file merging with Unison

mc — Thu, 13 Aug 2009 03:23:48 +0000

After trying in vein to find decent documentation on the Merge functionality of Unison I eventually gave in and invested an hour or two trying out different Linux based merge programs in order to find something Unison, the merge program and I were happy with.

So onto the diff-merging candidates:

VimDiff (part of Vim)

Doesn’t work too well with Unison. I can’t get gnome-terminal (my terminal of choice) to execute synchronously so I was forced to fall back on XTerm instead.

After using XTerm I immediately hit upon a problem: there is no sensible way of outputting the results of a merge in VimDiff. Which is a pity because I do prefer VIM as an editor but this lack of functionality is annoying (yes I could have used a wrapper script but I’m trying to keep this simple).

Meld

Very pretty but lacks features such as ‘Use Left-hand-side-file for all changes’ and some of the other filtering options provided by KDiff3.

Also, like, VimDiff, does not provide any sensible output mechanism of the eventually merged file.

KDiff3

Not as good looking as Meld but provides pretty much everything I want in a merge program including the all important merged file output that Unison requires.

Can get a little annoying though with its insentient pop-up boxes. I wish there were a ‘Dont show this option again’ option to each. KDE is usually quite good with this so I’m not sure why KDiff3 managed to escape this unspoken standard.

Conclusion

So how to use KDiff3 with Unison? First install kdiff3:

^?View Code BASH

apt-get install kidff3

Then open your Unison profiles .prf file and insert the following:

^?View Code INI

merge = Name * -> kdiff3 CURRENT1 CURRENT2 -L1 'Local File' -L2 'Remote File' -o NEW -m
confirmmerge = true

If you are comfortable with KDiff3 you could remove the ‘confirmmerge’ line which forces Unison to double check you actually want to accept the changes.

The downside to the above interactive merging process is there is no sensible way to preview the merge in Unison (the ‘View Merge’ button in the confirmation dialogue). For now though its preferable to not having this functionality at all.

Converting Null

mc — Fri, 24 Apr 2009 03:49:01 +0000

Simple shell script fix this week – convert all newlines to null characters.

Since most Linux shells have a major problem with doing this in a sensible way, the following (on my box called simply ’0′) takes any input (either from files or via a pipe) and converts the characters.

^?View Code PERL

#!/usr/bin/perl
# From: http://hash-bang.net/2009/04/converting-nullconverting-null/
# Author: Matt Carter 
while (<>) {
	s/\n/\x00/g;
	print;
}

So now commands like:

^?View Code BASH

find -type f | 0 | xargs -0 | mplayer

work perfectly (in the above case to play all files in directories recursively.

You may well ask why I don’t use the simple ‘-print0′ argument for the find program – because it doesn’t work when using later pipes.

For example if i wanted to sort the above, ‘sort’ would see the null symbol as a regular character.

So ’0′ works nicely in this case:

^?View Code BASH

find -type f | 0 | sort | xargs -0 | mplayer

Or even:

^?View Code BASH

find -type f | 0 | shuffle | xargs -0 | mplayer

To play all files recursively, in random order. See the article on shuffle for the source code of that filter.

Shuffling shell input

mc — Fri, 17 Apr 2009 04:10:02 +0000

While the Fisher-Yates shuffle sounds like 1920′s dance move, it is the standard method for shuffling larger arrays of data.

The below operates like a simple Unix filter taking an array of data (separated by newlines) and returning a quickly sorted output.

^?Download shuffle

#!/usr/bin/perl
# Usage: cat file | shuffle
# From: http://hash-bang.net/2009/04/shuffling-shell-inputshuffling-shell-input/
# Return a shuffled version of the input stream
# Author: Matt Carter 
 
sub fisher_yates_shuffle {
	my $array = shift;
	my $i;
	for ($i = @$array; --$i; ) {
		my $j = int rand ($i+1);
		next if $i == $j;
		@$array[$i,$j] = @$array[$j,$i];
	}
}
 
while(<>) {
	chomp;
	push @input, $_;
}
 
&fisher_yates_shuffle(\@input);
print join("\n",@input);

For example:

^?View Code BASH

ls | shuffle

Returns a randomized list of files in the current directory.

Easy Apache VirtualHost config

mc — Sun, 15 Mar 2009 11:23:13 +0000

Like most of the word I use Apache to serve up both my live and test websites.

The downside to having a box for development though is the constant config of apache to host these sites, most of which require absolute links (e.g. ‘/css/style.css’) to function.

The Apache snippet below sets up dynamic sub-domains which can be changed without reloading Apache every time you add, remove or update anything something. Simply drop your sites inside /var/www whenever you want a new subdomain. Alternatively you can symlink if they are hosted elsewhere on the box.

Its pretty easy to install, simply paste the below in your /etc/apache2/apache.conf file…

^?Download apache-conf-snippet.txt

# Easy virtual host config
# See http://hash-bang.net/2009/03/easy-apache-virtualhosteasy-apache-virtualhost/

DocumentRoot /var/www/
ServerAdmin admin@localhost
Options +FollowSymLinks -Indexes
LogLevel debug
ServerAlias localhost
ServerName localhost
RewriteEngine  on
RewriteLogLevel 3
RewriteCond    %{HTTP_HOST}  ^localhost
RewriteRule    ^(.*)$        /www/$1 [L]
RewriteCond    %{HTTP_HOST}  ^www.*
RewriteRule    ^(.*)$        /www/$1 [L]
RewriteCond    %{HTTP_HOST}  ^(.*)\.localhost
RewriteRule    ^(.*)$        /%1/$1 [L]

Now add your servers to the /etc/hosts file:

^?Download hosts-snippet

127.0.0.1      server.localhost

Now any directory you place in the /var/www directory automatically becomes a subdomain. You can now visit http:///server.localhost as a fully fledged webhost.

If you want to use another name than the rather boring ‘localhost’ simply replace the text in both text pastes above.

If only there were a way of removing that /etc/hosts hack it would mean zero config from then on. If anyone has any ideas do let me know. The addition to the hosts file seems to need applying if you are working from the same box the Apache server resides on. If you arn’t and the box is a local dedicated server its not needed at all and domains can be added and removed as necessary.

Trash with Bash

mc — Wed, 04 Mar 2009 05:15:15 +0000

One of the regrettably unavoidable aspects of the Unix shell like environments is the impedance between what a user says and what a user means. While this is present in all computing environments the sheer power of Unix based command lines make a potential mistake catastrophic.

Who amongst us has not at some point done something like:

^?View Code BASH

> rm * .tmp

^?View Code BASH

> rm *>tmp

The former makes the mistake of a space between the dot and the ‘tmp’ part and the latter the accidental holding down of the shift key while pressing the intended full stop.

While searching for an alternative for the I-have-done-this-too-many-times-and-now-its-embarrassing approach of nuking everything with the ‘rm’ command its time i did something about it.

Inserting the following in your ~/.bashrc file will remap the ‘rm’ command to a slightly safer move-to-trash like behavior. Its not comprehensive but it has saved my life on more than one occasion.

^?Download .bashrc

# Trash support by Matt Carter 
# Source and information: http://hash-bang.net/2009/03/trash-with-bash
function trash() {
	if [ -d "$HOME/.trashcan/$1" ]; then
		# Already exists in bin - remove
		rm -r "$HOME/.trashcan/$1"
	fi
	mv --target-directory=$HOME/.trashcan/ -- "$@"
}
alias "rm=trash"
alias "emptytrash=/bin/rm -rf $HOME/.trashcan/* $HOME/.trashcan/.??*"
alias 'rm!=/bin/rm -r'
mkdir ~/.trashcan 2>/dev/null

Now the command ‘rm’ moves files into ~/.trashcan. You can also use the command ‘rm!’ when you really mean delete immediately and the utility command ‘emptytrash’ to clean everything out.

Error reporting with CodeIgniter

mc — Mon, 23 Feb 2009 02:38:46 +0000

While CodeIgniter does come with a reasonable error logging tool its simple nature of just dumping a single line report to a file on a distant server does not seem too pro-active for my tastes.

The following helper replaces the default CI error reporting with a new error reporting interface that also emails any errors that occur to a nominated developer.

^?Download err_helper.php

 if (!defined('BASEPATH')) exit('No direct script access allowed');
/**
* Sensibly report of errors that occur in the system by sending that
* error to the developer
* Author: Matt Carter 
* Info: http://hash-bang.net/2009/02/error-reporting-with-cierror-reporting-with-ci/
*/
 
// Where to send the error report. Leave blank for nowhere
define('ERR_MAIL_TO', 'someone@somewhere.com');
 
 // Literal name of that person
define('ERR_MAIL_TO_NAME', 'Joe Random');
define('ERR_MAIL_FROM', 'root@freesweetsite.com');
define('ERR_MAIL_FROM_NAME', 'Error Daemon');
define('ERR_MAIL_METHOD', 'SMTP'); // Supported: SMTP
define('ERR_MAIL_HOST', 'localhost');
define('ERR_MAIL_SENDER', 'root@somewhere.com');
 
 // The subject of the mail. Supported tags: [TYPE], [FILE], [LINE], [STRING], [BASENAME]
define('ERR_MAIL_SUBJECT', 'Error detected: [TYPE] @ [BASENAME]:[LINE]');
 // Other things of interest to include in the email. CSV of supported values: POST, GET, SERVER, GLOBALS, SESSION
define('ERR_MAIL_FOOTERS', 'POST,GET,SESSION');
 
// Relative location of PHP mailer to this file
// (Not relative to the working directory because that doesn't specify correctly with fatal errors).
// By default this assumes that the 'phpMailer' folder is located in the same directory as this script.
define('ERR_PATH_PHPMAILER', 'phpMailer/class.phpmailer.php');
 
function err($errno, $errstr, $errfile, $errline, $errcontext) {
	$errtable = array(
		1 => 'Fatal',
		2 => 'Warning',
		4 => 'Parse Error',
		8 => 'Notice',
		16 => 'Core Error',
		32 => 'Core Warning',
		64 => 'Compile Error',
		128 => 'Compile Warning',
		256 => 'User Error',
		512 => 'User Warning',
		1024 => 'User Notice',
		2048 => 'Strict Notice',
		4096 => 'Recoverable Error',
		8192 => 'Deprecated',
		16384 => 'User Deprecated',
	);
	$message = "";
	$message .= "\"err-box\">";
	$message .= "\"err-table\">";$message.="";$message.="";$message.="";$message.="";$message.="";$message.="
	  \"100px\">Type: {$errtable[$errno]}
	  Error: $errstr
	  File: $errfile
	  Line: $errline
	  Context: $errcontext
	  
";
	$traces = debug_backtrace();
	array_shift($traces);
	if ( (count($traces) > 1) && ($traces[0]['function'] != 'err_shutdown') ) { // Ignore fatal shutdown traces
		$message .= "\"100%\" class=\"err-table-stack\">";foreach($tracesas$offset=>$trace){// Calculate line numberif($offset==0){// First in trace$message.="";}$message.="\"50px\">Line Function
		      
			
			     
				  
\"text-align: center\">$errline ";
			} else // Nth in trace
				$message .= "
\"text-align: center\">" . (isset($trace['line']) ? $trace['line'] : ' ') . " ";
			// Calculate arg stack
			$trace['argstack'] = '';
			if (isset($trace['args']) && $trace['args']) {
				foreach ($trace['args'] as $arg)
					$trace['argstack'] .= _err_human($arg) . ' , ';
				if ($trace['argstack']) $trace['argstack'] = substr($trace['argstack'], 0, -3);
			}
			// Output context
			if (isset($trace['object'])) { // Object error
				$message .= "{$trace['class']}->{$trace['function']}({$trace['argstack']})";
			} else // Function error
				$message .= "{$trace['function']}({$trace['argstack']})";
			$message .= "
		
		  
";
	}
	$message .= "
";
	if (ERR_MAIL_TO) {
		if (!file_exists($p = dirname(__FILE__) . '/' . ERR_PATH_PHPMAILER)) {
			echo "Cannot find PHP mailer at the relative path '" . ERR_PATH_PHPMAILER ."'. Make sure it is located there to send mails";
		} else {
			require_once($p);
			$mailobj = new PhpMailer();
			if (ERR_MAIL_METHOD == 'SMTP') $mailobj->IsSMTP();
			$mailobj->IsHTML(TRUE);
			$mailobj->CharSet = 'utf-8';
			$mailobj->Host = ERR_MAIL_HOST;
			$mailobj->Sender = ERR_MAIL_SENDER;
			$mailobj->From = ERR_MAIL_FROM;
			$mailobj->FromName = ERR_MAIL_FROM_NAME;
			$mailobj->AddAddress(ERR_MAIL_TO, ERR_MAIL_TO_NAME);
			$mailobj->Subject = strtr(ERR_MAIL_SUBJECT, array(
				'[TYPE]' => $errtable[$errno],
				'[FILE]' => $errfile,
				'[BASENAME]' => basename($errfile),
				'[LINE]' => $errline,
				'[STRING]' => $errstr,
			));
			$extras = preg_split('/\s*,\s*/', ERR_MAIL_FOOTERS);
			if (in_array('GET', $extras)) $message .= _err_dump_array($_GET, 'Get');
			if (in_array('POST', $extras)) $message .= _err_dump_array($_POST, 'Post');
			if (in_array('SESSION', $extras)) $message .= _err_dump_array(isset($_SESSION) ? $_SESSION : array(), 'Session');
			if (in_array('SERVER', $extras)) $message .= _err_dump_array($_SERVER, 'Server');
			if (in_array('GLOBALS', $extras)) $message .= _err_dump_array($_GLOBALS, 'Globals');
			$mailobj->Body = $message;
			$status = $mailobj->Send();
		}
	}
	echo $message;
	return TRUE;
}
 
// Catch fatal errors
function err_shutdown() {
	$err = error_get_last();
	if (in_array($err['type'], array(E_ERROR, E_CORE_ERROR, E_COMPILE_ERROR, E_USER_ERROR)))
		err($err['type'], $err['message'], $err['file'], $err['line'], 'Fatal error');
}
 
function _err_human($what) {
	if (is_object($what)) {
		return get_class($what);
	} elseif (is_array($what)) {
		return "Array[" . count($what) . "]";
	} else
		return $what;
}
 
function _err_dump_array($array, $title) {
	if ($array) {
		$out = '';$out.="";foreach(array_keys($array)as$key)$out.="";$out.='
		  \"2\">Dump of $title array
Key Value
		   
			  $key " . _err_human($array[$key]) . "
		  
';
	} else {
		$out = "$title is empty
";
	}
	return $out;
}
set_error_handler('err', E_ALL);
register_shutdown_function('err_shutdown');
?>

Installation of the component is similar to any CI helper: drop the file into the application/system/helpers directory and create the associated entry in the application/system/config/autoload.php file like so:

^?View Code PHP

1	$autoload['helper'] = array('err');

Then open the above and change the constants at the top of the file to specify where the error messages are sent.

In order to send mail the above component needs the truly excellent PHPMailer package which can be stashed in the same helpers directory. If you do decide to move it somewhere else change the corresponding constant that specifies the location of the library. A small note of warning though – the path to the PHP mailer libraries must be relative to the current file NOT the current working directory. This is due to how PHP handles fatal errors which for some reason sets the working directory to ‘/’.

Should there be any interest I may extend the above with other useful features such as RSS, SMS (text messaging) or other non-SMTP methods of emailing.

Talking in tongues – UTF8 with CodeIgniter

mc — Mon, 16 Feb 2009 02:55:23 +0000

PHP 4 & 5 unfortunately have major problems working with UTF8. Hopefully this will be solved with PHP6 and its fancy pants new rendering interface.

Until then we have to make do and mend.

First setup your database to work with UTF8. I won’t waste time telling you how to do this in MySQL as many people far brighter than I have written more on the subject.

CodeIgniter comes with UTF8 enabled out of the box so there is little to do configuration wise. Unfortunately pasting a test string such as: 検索 (which I stole from this Wikipedia page) into a CI input box will quickly lead to calamity as CI tries to save the string as ASCII.

Simple solution then, save the following helper in your system/application/helpers folder:

^?Download utf8_helper.php

 if ( ! defined('BASEPATH')) exit('No direct script access allowed');
/**
* Rewrite all outgoing text into UTF8 compatible streams
* Author: Matt Carter 
* Info: http://hash-bang.net/2009/02/utf8-with-codeigniter
*/
function ob_utf8($string) {
	return utf8_decode($string);
}
ob_start('ob_utf8');
 
foreach ($_POST as $key => $val) // Re-write all incoming text into UTF8 streams
	$_POST[$key] = utf8_encode($val);
?>

Then simply add it to your system/application/autoload.php:

^?View Code PHP

1	$autoload['helper'] = array('utf8');

The helper will automatically convert incoming POST data into MySQL compatible UTF8 and convert outgoing text into HTML UTF8 streams.

Zapping processes in Bash

mc — Sat, 24 Jan 2009 00:14:15 +0000

The following is a handy little script I wrote which politely asks a collection of matching processes to exit. After a second the process is forcibly killed.

This command is designed as a drop-in replacement for the slightly cryptic pgrep and pkill commands.

^?Download zap.sh

zap() {
	# Usage: zap [SIGNAL|-NUMERIC|shoot] 
	SIGNAL=''
	case "$1" in
		shoot|-0) SIGNAL='SHOOT';;
		term|-15) SIGNAL='TERM';;
		kill|-9) SIGNAL='KILL';;
		hup|-1) SIGNAL='HUP';;
	esac
	if [ "$SIGNAL" != '' ]; then
		shift
	else
		SIGNAL='SHOOT'
	fi
	PROCS=`ps ax -eo pid,comm | fgrep "$1"`
	MODE=0
	for DATA in $PROCS; do
		if [ "$MODE" -eq 0 ]; then
			PID="$DATA"
			MODE=1
		else
			CMD="$DATA"
			MODE=0
			if [ "$SIGNAL" == 'SHOOT' ]; then
				echo -n "Shooting #$PID - $CMD..."
				kill $PID
				sleep 1
				kill -9 $PID
				echo "Shot"
			else
				echo -n "Killing #$PID - $CMD..."
				kill $SIGNAL $PID
				echo "Killed"
			fi
		fi
	done
}

To install it simply dump the above text inside your existing ~/.bashrc file.

Usage is quite simple:

To politely kill all processes (then force-killing if it still does not die) containing the string ‘gnome’:

^?View Code BASH

zap gnome

To just kill-forcefully:

^?View Code BASH

1	zap -9 gnome

Autorun as Administrator in Vista

mc — Sat, 17 Jan 2009 22:16:24 +0000

When asked how to automate the installation of software the other day I was a little dismayed that no-one seemed to have covered the topic of auto-running a batch file from a USB disk as an administrative user.

Admin level access is obviously required in order to install software without relentless ‘Program X requires administrative access’ UAC prompts.

Like most things in Vista the solution is exceptionally stupid and requires significant trips with Google to rather obscure second-hand Microsoft knowledge base articles.

The overview is something like this:

First create the autorun.inf file:

^?Download autorun.inf

[autorun] 
open=invoke.bat 
icon=autorun.ico,0
label=Setup computer from USB disk

So this file simply sets up the autorun.inf file which contains exactly what to list in the Vista ‘Autoplay’ dialog when the USB disk is inserted. You will probaly want to rename the ‘Label’ line and perhaps put a pretty icon on your disk called ‘autorun.ico’.

Now create your actual batch file that you wish to run as admin and call it ‘setup.bat’.

As a small note of caution. For some reason Vista does not change to this files active working directory when executing. I can really think of no reason this behavior exists so you might want to add the following rather cryptic command as the first in the batch file. This changes the active directory into the current batch file (in this case ‘setup.bat’) directory.

^?Download setup.bat

1 2	@ECHO OFF cd /d %~dp0

There obvious when you think about it isn’t it. Shame on you for not knowing about the handy and invisible shell variable “~dp0″. I am sure there is a long and interesting story about why this variable is so called and why it doesnt show up with the rest of things when you type ‘set’. This is why I switched to Linux some time ago.

Anyway, now we’ve done that create a shortcut to the ‘Setup.bat’ file and rename it to ‘setup.lnk’ (remember that the ‘.lnk’ bit will always be invisible to you anyway so when you rename in explorer all you will see is the ‘setup’ bit sans extension).

Open the shortcuts properties and hit the ‘Advanced’ button. Tick the ‘Run as Administrator’ box.

Finally, lets join it all together by creating the ‘Invoke.bat’ file which runs the shortcut (which will in turn run the ‘setup.bat’ program after asking via UAC for administrative permission).

^?Download invoke.bat

1 2	@ECHO OFF "Setup.lnk"

Now save everything and remove you disk (safely) and re-insert. You will now be able to run the ‘setup.bat’ file which should contain all your auto-install scripts after a UAC admin prompt. Yey.

Pretty URLS in CodeIgniter

mc — Sun, 11 Jan 2009 22:49:21 +0000

CodeIgniter has to be my favorite framework for PHP. The way it keeps out of your way while working to an MVC standard is something deserving of the highest praise.

For reasons passing understanding though the programmers of this excellent system have desided not to provide pretty URL’s out of the box. Getting infomation on this is a little tricky so here is my take on the situation.

Simply dump the following into a file called ‘.htaccess’ (Note the starting Dot) in the root path (thats the one at the very start of your path tree that should contain the ‘system’ folder).

^?Download .htaccess

RewriteEngine on
RewriteCond %{REQUEST_FILENAME} -f
RewriteRule ^(.*)$		- [L]
 
RewriteCond $1 !^(index\.php|images|robots\.txt)
RewriteRule ^(.*)$ /index.php/$1 [L]

As with most mod_rewrite hacks you will need that enabled on an apache server. Its very rare to find a hosting company that doesn’t use this setup so you should be fine.

You will also need to change the following variable to a blank value in the system/application/config/config.php file:

^?View Code PHP

1	$config['index_page'] = '';

And you’re done. From now on your Urls are addressed in the form: http://SITE/CONTROLLER/METHOD/VALUE1/VALUE2 (e.g. http://mysite.com/users/edit/123123)

Missing PHP Functions: getopts()

mc — Tue, 23 Dec 2008 04:24:51 +0000

This function is intended as a complete replacement for the horribly crippled getopt() native PHP function and provide extended functionality.

The use of this library means lots of great command-line-fu becomes readily available without any unnecessary validation tediousness messing up the first half of your script.

To use simply add the (ahem) hash-bang to the top of your PHP script and make the script executable.

An example of a correct setup would be:

^?Download getopts_example.php

#!/usr/bin/php -qC

require('getopts.php');
$opts = getopts(array(
	'a' => array('switch' => 'a','type' => GETOPT_SWITCH),
	'b' => array('switch' => array('b','letterb'),'type' => GETOPT_SWITCH),
	'c' => array('switch' => 'c', 'type' => GETOPT_VAL, 'default' => 'defaultval'),
	'd' => array('switch' => 'd', 'type' => GETOPT_KEYVAL),
	'e' => array('switch' => 'e', 'type' => GETOPT_ACCUMULATE),
	'f' => array('switch' => 'f'),
),$_SERVER['argv']);
print_r($opts);
?>

In the above the script can now be run as:

^?View Code BASH

./getopts_example.php -a -b

With the incoming options (in this case the switches ‘a’ and ‘b’) being set in the $opts variable.

Full documentation as well as extensive examples are included in the source which can be found below.

^?Download getopts.php

#!/usr/bin/php -qC

	/**********************************************************************************
	* Coded by Matt Carter (M@ttCarter.net)                                           *
	***********************************************************************************
	* getOpts                                                                       *
	* Extended CLI mode option and switch handling                                    *
	*                                                                                 *
	**********************************************************************************/
/*
GetOpt Readme
+++++++++++++++
 
getOpt is a library to load commandline options in replacement for the horribly inflexible 'getopts' native php function. It can be invoked using the typical 'require', 'include' (or their varients) from any PHP scripts.
 
LEGAL STUFF
===========
This code is covered under the GPL with republishing permissions provided credit is given to the original author Matt Carter (M@ttCarter.com).
 
LATEST VERSIONS
===============
The latest version can be found on the McStuff website currently loadted at http://ttcarter.com/mcstuff or by contacting the author at M@ttCarter.com (yes thats an email address).
 
QUICK EXAMPLE
=============
#!/usr/bin/php -qC
 array('switch' => 'a','type' => GETOPT_SWITCH),
	'b' => array('switch' => array('b','letterb'),'type' => GETOPT_SWITCH),
	'c' => array('switch' => 'c', 'type' => GETOPT_VAL, 'default' => 'defaultval'),
	'd' => array('switch' => 'd', 'type' => GETOPT_KEYVAL),
	'e' => array('switch' => 'e', 'type' => GETOPT_ACCUMULATE),
	'f' => array('switch' => 'f'),
),$_SERVER['argv']);
?>
 
When used with the commandline:
>./PROGRAM.php -ab -c 15 -d key=val -e 1 --letterb -d key2=val2 -eeeeeee 2 3
 
Gives the $opt variable the following structure:
$opt = Array (
	[cmdline] => Array (
		[0] => 1
		[1] => 2
		[2] => 3
	)
	[a] => 1
	[b] => 1
	[c] => 15
	[d] => Array (
		[key] => val
		[key2] => val2
	)
	[e] => 8
	[f] => 0
)
 
Of course the above is a complex example showing off most of getopts functions all in one.
 
Types and there meanings
========================
 
GETOPT_SWITCH
	This is either 0 or 1. No matter how many times it is specified on the command line.
 
	>PROGRAM -c -c -c -cccc
	Gives:
	$opt['c'] = 1;
 
	>PROGRAM
	Gives:
	$opt['c'] = 0
 
GETOPT_ACCUMULATE
	Each time this switch is used its value increases.
 
	>PROGRAM -vvvv
	Gives:
	$opt['v'] = 4
 
GETOPT_VAL
	This expects a value after its specification.
 
	>PROGRAM -c 32
	Gives:
	$opt['c'] = 32
 
	Multiple times override each precursive invokation so:
 
	>PROGRAM -c 32 -c 10 -c 67
	Gives:
	$opt['c'] = 67
 
GETOPT_MULTIVAL
	The same format as GETOPT_VAL only this allows multiple values. All incomming variables are automatically formatted in an array no matter how few items are present.
 
	>PROGRAM -c 1 -c 2 -c 3
	Gives:
	$opt['c'] = array(1,2,3)
 
	>PROGRAM -c 1
	Gives:
	$opt['c'] = array(1)
 
	>PROGRAM
	Gives:
	$opt['c'] = array()
 
GETOPT_KEYVAL
	Allows for key=value specifications.
 
	>PROGRAM -c key=val -c key2=val2 -c key3=val3 -c key3=val4
	Gives:
	$opt['c'] = array('key1' => 'val2','key2' => 'val2','key3' => array('val3','val4');
 
*/
 
define('GETOPT_NOTSWITCH',0); // Internal use only
define('GETOPT_SWITCH',1);
define('GETOPT_ACCUMULATE',2);
define('GETOPT_VAL',3);
define('GETOPT_MULTIVAL',4);
define('GETOPT_KEYVAL',5);
 
/**
* @param array $options The getOpts specification. See the documentation for more details
* @param string|array $fromarr Either a command line of switches or the array structure to take options from. If omitted $_SERVER['argv'] is used
* @return array Processed array of return values
*/
function getopts($options,$fromarr = null) {
	if ($fromarr === null)
		$fromarr = $_SERVER['argv'];
	elseif (!is_array($fromarr))
		$fromarr = explode(' ',$fromarr); // Split it into an array if someone passes anything other than an array
	$opts = array('cmdline' => array()); // Output options
	$optionslookup = array(); // Reverse lookup table mapping each possible option to its real $options key
	foreach ($options as $optitem => $props) { // Default all options
		if (!isset($props['type'])) { // User didnt specify type...
				$options[$optitem]['type'] = GETOPT_SWITCH; // Default to switch
				$props['type'] = GETOPT_SWITCH; // And again because we're not using pointers here
		}
		switch ($props['type']) {
				case GETOPT_VAL:
					if (isset($props['default'])) {
						$opts[$optitem] = $props['default'];
						break;
					} // else fallthough...
				case GETOPT_ACCUMULATE:
				case GETOPT_SWITCH:
					$opts[$optitem] = 0;
					break;
				case GETOPT_MULTIVAL:
				case GETOPT_KEYVAL:
					$opts[$optitem] = array();
		}
		if (is_array($props['switch'])) { // Create the $optionslookup var from an array of aliases
				foreach ($props['switch'] as $switchalias)
					$optionslookup[$switchalias] = $optitem;
		} else { // Create the $optionslookup ref as a simple pointer to the hash
			$optionslookup[$props['switch']] = $optitem;
		}
	}
 
	$inswitch = GETOPT_NOTSWITCH;
	for ($i = 1; $i < count($fromarr); $i++) {
		switch ($inswitch) {
			case GETOPT_MULTIVAL:
			case GETOPT_VAL:
				if (substr($fromarr[$i],0,1) == '-') // Throw error if the user tries to simply set another switch while the last one is still 'open'
					die("The option '{$fromarr[$i]}' needs a value.\n");
				GETOPT_setval($opts,$options,$inswitch_key,$fromarr[$i]);
				$inswitch = GETOPT_NOTSWITCH; // Reset the reader to carry on reading normal stuff
				break;
			case GETOPT_KEYVAL: // Yes, the awkward one.
				if (substr($fromarr[$i],0,1) == '-') // Throw error if the user tries to simply set another switch while the last one is still 'open'
					die("The option '{$fromarr[$i]}' needs a value.\n");
				$fromarr[$i] = strtr($fromarr[$i],':','='); // Replace all ':' with '=' (keeping things simple and fast.
				if (strpos($fromarr[$i],'=') === false)
					die("The option '$inswitch_userkey' needs a key-value pair. E.g. '-$inswitch_userkey option=value'");
				GETOPT_setval($opts,$options,$inswitch_key,explode('=',$fromarr[$i]));
				$inswitch = GETOPT_NOTSWITCH; // Reset the reader to carry on reading normal stuff
				break;
			case GETOPT_NOTSWITCH: // General invokation of no previously complex cmdline options (i.e. i have no idea what to expect next)
				if (substr($fromarr[$i],0,1) == '-') {
					// Probably the start of a switch
					if ((strlen($fromarr[$i]) == 2) || (substr($fromarr[$i],0,2) == '--')) { // Single switch OR long opt (might be a weird thing like VAL, MULTIVAL etc.)
							$userkey = ltrim($fromarr[$i],'-');
							if (!isset($optionslookup[$userkey]))
									die("Unknown option '-$userkey'\n");
								$hashkey = $optionslookup[$userkey]; // Replace with the REAL key
							if (($options[$hashkey]['type'] == GETOPT_SWITCH) || ($options[$hashkey]['type'] == GETOPT_ACCUMULATE)) {
								GETOPT_setval($opts,$options,$hashkey,1); // Simple enough - Single option specified in switch that needs no params.
							} else { // OK the option needs a value. This is where the fun begins
								$inswitch = $options[$hashkey]['type']; // Set so the next process cycle will pick it up
								$inswitch_key = $hashkey;
								$inswitch_userkey = $userkey;
							}
					} else {
						// Multiple letters. Probably a bundling
						for ($o = 1; $o < strlen($fromarr[$i]); $o++) {
							$hashkey = substr($fromarr[$i],$o,1);
							if (!isset($optionslookup[$hashkey]))
									die("Unknown option '-$hashkey'\n");
							if (($options[$optionslookup[$hashkey]]['type'] != GETOPT_SWITCH) && ($options[$optionslookup[$hashkey]]['type'] != GETOPT_ACCUMULATE))
								die("Option '-$hashkey' requires a value.\n");
							GETOPT_setval($opts,$options,$optionslookup[$hashkey],1);
						}
					}
				} else {
					$opts['cmdline'][] = $fromarr[$i]; // Just detritus on the cmdline
				}
				break;
		}
	}
	return $opts;	
}
 
function GETOPT_setval(&$opts,&$options,$key,$value) {
	switch ($options[$key]['type']) {
		case GETOPT_VAL:
		case GETOPT_SWITCH:
			$opts[$key] = $value;
				break;
		case GETOPT_ACCUMULATE:
			$opts[$key]++;
				break;
		case GETOPT_MULTIVAL:
			$opts[$key][] = $value;
			break;
		case GETOPT_KEYVAL:
			$opts[$key][$value[0]] = $value[1];
	}
}
?>

If you do use this script, please take a moment to add any comments or suggestions below.

Missing PHP Functions: array_totree()

mc — Sat, 13 Dec 2008 01:57:01 +0000

^?View Code PHP

array_totree( $array, $seperator = "/" )

Splits a given array into a tree formed hash array.

This is useful when a large array of strings needs splitting into a hierarchical array structure.

For example in incoming array structure

^?View Code PHP

$a = array(
	'a/a/a',
	'a/b/b',
	'a/b/c',
	'a/c/c',
	'c/a/a'
);

Is returned as:

^?View Code TEXT

array(
	"a" => array(
		"a" => array(
			"a" => array()
		),
	),
	"b" => array(
		"b" => array(),
		"c" => array()
	),
	"c" => array(
		"c" => array()
	),
	"c" => array(
		"a" => array(
			"a" => array()
		)
	)
);

The function:

^?Download array_totree.php

function array_totree($in, $splitchar = '/') {
        $out = array();
        foreach ($in as $item) {
                $bits = explode($splitchar,$item);
                $outref =& $out;
                foreach ($bits as $bit) {
                        if (!isset($outref[$bit]))
                                $outref[$bit] = array();
                        $outref =& $outref[$bit];
                }
        }
        return $out;
}

Templating in PHP in 10 seconds flat

mc — Fri, 05 Dec 2008 21:50:16 +0000

One of the rather messy practices that the PHP documentation actually encourages is the practice of using include or require to correctly layout a web page.

The PHP manual suggests that two pages be created: header and footer, and that these are included at the beginning and end of each document.

Thus for a ‘contact us’ page the contact.php file would look something like:

^?View Code PHP

1
2
3

 include("header.php") ?>
... The contact pages HTML ...
 include("footer.php") ?>

While this does work, there are easier ways to accomplish the same thing and still maintain compatibility with editors such as Dreamweaver which seems to choke on even a small amount of PHP.

The under-documented auto_prepend_value and auto_append_values get a brief mention in the ini directives documentation but I thought it would be nice to show an example of how these can be used in the wild,

Adding the following to either an existing ‘.htaccess’ (note the starting dot) or downloading the below file will do pretty much the same as the above contact.php file example did only without needing to specify the files in the beginning and ends of each separate file.

^?Download .htaccess

1 2	php_value auto_prepend_file "header.php" php_value auto_append_file "footer.php"

And as with all .htaccess directives you can override these on a directory basis. So if you need a different header and footer when inside the ‘invoices’ directory dump another copy of the above into that directory changing it as needed.

And yes this method can be merged with the previous post to work with the URL prettifier.

URL prettification in 10 seconds flat

mc — Fri, 28 Nov 2008 21:35:25 +0000

A word to all PHP, ASP, Python and Perl web-devs out there:

http://somewhere.com/contact.php

Is soooo 1990′s.

URL prettification has always been seen to be the exclusive domain of larger frameworks but with Apache it really isn’t that hard.

Simply paste the following into a file named ‘.htaccess’ (note the starting ‘dot’) and dump it in your website to allow the extension of your script to be ‘guessed’ by Apache should it not be provided.

This hack obviously requires mod_rewrite but since every hosting provider and their dog provides this these days i would say not having it enabled would be the exception rather than the rule

^?Download .htaccess

RewriteEngine On
RewriteBase /
 
RewriteCond %{REQUEST_FILENAME}.php -f
RewriteRule ^(.*)$		$1.php [L]

ASP, Python and Perl people either add your .asp, .py or .pl sections under or above the .php bits or simply replace them.

There, now we can use:

http://somewhere.com/contact

But the old way (with .php extension) is still valid too.

Finally we put an end to this silly file extension nastiness.