damonparker.org » Technical

MySQL Error Function Wrapper for PHP

damonp — Tue, 08 Feb 2011 00:01:32 +0000

I was recently asked to supply some development and debugging functionality to a web application built for a client. The following function can be configured to popup for only your IP, and gives an error message containing the SQL, line number and file for easy debugging of the error.

I like this function over my current hobbled together debug kit because the display is positioned top center of the page via CSS no matter where the error occurs. Plus it includes a hide button to hide the majority of the error output and remove button to remove the error display altogether.

function mysql_error_wrapper($q, $sql='', $line='', $file='') {
if($_SERVER['REMOTE_ADDR'] != 'YOUR LOCAL IP') return false;
?>

echo '

';
echo '\'sqlerror\')">hide - remove';
echo '

MySQL error: '.mysql_errno().' Line: #'.$line.' '.basename($file).'

';

echo '

';

        

        echo wordwrap(mysql_error());

        

        if($sql != '')  {

            echo 'SQL
'.wordwrap($sql);

        }



        if($line != '') {

            echo 'Line
'.$line;

        }

        

        if($file != '') {

            echo 'File
'.$file;

        }

                    

        echo '

';
echo '

';

}
?>

Usage example:

$sql = "YOUR SQL STATEMENT";
$q = mysql_query($sql, $db);
if(!$q) mysql_error_wrapper($q, $sql, __LINE__, __FILE__);
?>

Download a Remote File Using PHP and cURL

damonp — Thu, 03 Feb 2011 17:02:51 +0000

Some years back, I posted a function to download a remote file with PHP. The function was useful when cURL and other URL/remote file functions had been disabled for security reasons. At the time, cURL on PHP was relatively new and many hosting setups didn’t include the cURL PHP module.

Support for PHP-cURL is pretty standard now, so I thought I’d update the the function to use cURL now. In addition, the function no longer returns a buffer containing the file data which can cause memory issues in PHP when dealing with large files. Pass this updated function a remote URL and local file path and it will download the file and save it to the local path.

This function is useful to retrieve remote images, download HTML pages and download any remote files.

function http_get_file($remote_url, $local_file) {

$fp = fopen($local_file, 'w');

$cp = curl_init($remote_url);
curl_setopt($cp, CURLOPT_FILE, $fp);

$buffer = curl_exec($cp);

curl_close($cp);
fclose($fp);

return true;
}
?>

Hardcode WordPress Site URL

damonp — Tue, 11 Jan 2011 20:13:16 +0000

I’m working on a project for mobile devices and need to be able to setup the same WordPress install on both the .mobi and the .com domain. This snippet lets you hardcode the URL and home configurables in wp_config.php. We use one setup of configurables for the .mobi side and another set for the .com.

define('WP_HOME','http://example.com');
define('WP_SITEURL','http://example.com');

Thanks to the WordPress Codex.

HTML Image Caption

damonp — Thu, 11 Nov 2010 04:53:09 +0000

id="image-caption"> style="border: 1px solid black; float: right; margin: 0 0 10px 10px;" src="/images/imagename.jpg" border="0" alt="" width="175" height="132" />
class="caption">HTML Image Caption

Cannot find terminfo entry for ‘xterm-256color’

damonp — Wed, 10 Nov 2010 14:16:14 +0000

Check if you have the terminfo file installed.

find /lib/terminfo /usr/share/terminfo -name "*256*"

No results? Install ncurses-term.

sudo apt-get install ncurses-term

Debugging Wifi Connectivity and Routing

damonp — Fri, 11 Jun 2010 21:33:32 +0000

Sometimes wifi connectivity issues can be massaged a little by getting a little pushy with it… turn your internal airport card off. Leave it off for a minute then turn it back on and see if by forcing it to attempt to re-connect to your local network. Oftentimes this will clear up minor issues.

Check your routing tables:

netstat -nr

Get just the default route:

netstat -nr | grep default

In action:

[root@howie ~]$ netstat -nr | grep default
5:default 192.168.1.1 UGSc 11 5 en1

Enable Sendmail for PHP mail() in OSX

damonp — Thu, 25 Feb 2010 22:05:41 +0000

Since this didn’t dawn on me for thirty minutes while I pursued other avenues…

In /etc/hostconfig add/edit a line like:

MAILSERVER=-YES-

Note to self: Look for more OSX server administration clients.

Apache Log Grepping

damonp — Mon, 14 Sep 2009 18:34:51 +0000

Nothing beats a full stats package, but with a little grepping and a logfile and we can figure out some quick statistics.

Get only hits coming from Google.com/search:

grep 'google.com/search' access_log | head -1

Extract only the referrer field:

grep 'google.com/search' access_log | head -1 | awk '{print $11}'

Get the search terms only:

grep 'google.com/search' access_log | \
head -1 | \
awk '{print $11}' | \
cut -d\? -f2 | cut -d\& -f1 | \
sed 's/+/ /g;s/%22/"/g;s/q=//'

Here’s a little script that puts it all together. It finds the unique search terms, cleans out the trash, sorts them and list the top twenty five in order of descending hit count.

#!/bin/sh
LOG="/var/logs/httpd/access_log"
grep 'google.com/search' $LOG | \
awk '{print $11}' | \
cut -d\? -f2 | cut -d\& -f1 | \
sed 's/+/ /g;s/%22/"/g;s/q=//' | \
sed 's/%[0-9a-fA-F][0-9a-fA-F]/ /g;s/"//g' | \
grep -v '=' | sort | uniq -c | sort -rn | head -25

To see them all remove the | head -25 statement at the end of the command.

Thanks to an article at Linux Journal for the examples.

Find setuid root Files

damonp — Fri, 11 Sep 2009 04:29:20 +0000

Find all setuid / setgid files owned by root:

find / -user root -type f $ -perm -4000 -o -perm -2000 $ -exec ls -ld '{}' \;

Find all setuid / setgid files owned by any user:

find / -type f $ -perm -4000 -o -perm -2000 $ -exec ls -ld '{}' \;

Debugging HTTP Headers with cURL

damonp — Mon, 31 Aug 2009 16:05:39 +0000

curl -I http://damonparker.org

More info on cURL