Stay well away from W3schools (why? – see http://w3fools.com/)
When monitoring websites with Nagios, it’s common to get the error “HTTP WARNING: HTTP/1.1 403 Forbidden“.
Use the -H option to specify the host name for the web site e.g.
define service{
use generic-service
host_name andymadge.com
service_description HTTP
check_command check_http!-H www.andymadge.com
}
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When editing source code you often come across files with additional blank lines that shouldn’t be there.
The problem is generally caused by someone editing the file with a text editor which doesn’t understand and maintain the different newline types. You then end up with a file containing a mix of different line endings. Read more…
This article is about using salting techniques to improve the security of authentication for websites. Examples are in PHP but the techniques apply to any language. Read more…
I’ve just upgraded to Firefox 3.5 and noticed that tooltips had stopped working. I then checked Internet Explorer 8 and found tooltips were not working there either.
On investigation it seems that the two problems were unrelated, but here are the solutions to both of them… Read more…
SysInternals tools are a fantastic set of free utilities written by Mark Russinovich and Bryce Cogswell. There are invaluable for system admins and Windows Power Users.
There is now a website that allows you to run most of the SysInternals tools directly, so you don’t have to find the right page, download it and unzip. You just run it directly from:
http://live.sysinternals.com/<tool>.exe
e.g.
http://live.sysinternals.com/procexp.exe
This works better in Internet Explorer than Firefox, since you can run the tool without saving it first.
In Unix you can pipe the output of a command into the GREP command in order to only display the lines that contain a required string. This is means you don’t have to scroll through pages of output to find the bit you’re interested in. The DOS equivalent of GREP is FIND:
Searches for a text string in a file or files. FIND [/V] [/C] [/N] [/I] [/OFF[LINE]] "string" [[drive:][path]filename[ ...]] /V Displays all lines NOT containing the specified string. /C Displays only the count of lines containing the string. /N Displays line numbers with the displayed lines. /I Ignores the case of characters when searching for the string. /OFF[LINE] Do not skip files with offline attribute set. "string" Specifies the text string to find. [drive:][path]filename Specifies a file or files to search. If a path is not specified, FIND searches the text typed at the prompt or piped from another command.
this can be useful with the netstat command:
netstat -ano | find /i ":80"
or when viewing the DNS cache:
ipconfig /displaydns | find /i "google"
Although that isn’t ideal since the output of ipconfig isn’t really formatted to play nicely with the find command.
Reference: http://nzpcmad.blogspot.com/2007/07/dos-grep-equivalent-find-command.html
Windows caches DNS responses to speed up network access, but sometimes this can cause a problem. Positive responses (i.e. successful lookups) are cached for 24 hours, and negative responses (i.e. failed lookups) for 5 minutes.
If you make changes to DNS and want to test the results straight away, you need to clear the cache with:
ipconfig /flushdns
You can view the current cache with:
ipconfig /displaydns
or
ipconfig /displaydns | more
to see a screen at a time
Some suggestions from around the web:
To extend the battry life, switch off WiFi, 3G and Bluetooth when you’re no using them. Hopefully someone will soon write a utility to do this easily and quickly from one place. I may even give it a go myself…
The screen will flash and image will be saved to Camera Roll