HTTP 1.1 protocol, as most of the other protocol, uses headers for the communication between client (usually browser) and server.

An example of the header looks like:
HTTP/1.1 200 OK
Date: Wed, 24 Mar 2010 04:03:41 GMT
Server: Apache/2.2.11 (Unix) DAV/2 PHP/5.2.11 with Suhosin-Patch mod_ssl/2.2.15 OpenSSL/0.9.8k
X-Powered-By: PHP/5.2.11
Set-Cookie: phpbb3_qxggi_u=1; expires=Thu, 24-Mar-2011 04:03:41 GMT; path=/; domain=forum.ivorde.ro; HttpOnly
Set-Cookie: phpbb3_qxggi_k=; expires=Thu, 24-Mar-2011 04:03:41 GMT; path=/; domain=forum.ivorde.ro; HttpOnly
Set-Cookie: phpbb3_qxggi_sid=514ad39b91e1e29bcb1a7553dcb8f4a7; expires=Thu, 24-Mar-2011 04:03:41 GMT; path=/; domain=forum.ivorde.ro; HttpOnly ...

Usually I keep my sources available at all times because apache or php could require a new module to be installed (sooner or later). I will post here how to install apache mod_rewrite module without recompiling whole apache from source.

Below is the source of the mod_rewrite apache module on my system.


I will be using the apache extension tool (apxs):
man apxs: ...

Php 5.3 introduces a cool new alternative to the old libmysql library: mysqlnd (mysql native driver).

How to compile php with this driver or more details about mysqlnd are not scope of this post, but authentication method is.

By default, Mysql is using old_passwords method of storing passwords in 16 char length. Mysqlnd usses a new authentication engine which stores passwords in 41 character length.

To check how mysql currently stores passwords:
mysql> show variables ...

fuser -- list IDs of all processes that have one or more files open

man fuser:

Portupgrade, portinstall are two tools used to upgrade installed packages or install new ones via ports or packages systems.

man portupgrade:

To encode a string into base64, echo and openssl system utilities can be used:


The -n switch to echo is used to supress echoing a new line character. For example, below is a difference between base64 encoded string that doesn't contain newline and on that does:

Fortunately for debugging HTTP connections, there is a very simple way of generating one from command line when elinks or lynx are not available.

For this we need the most basic http command and header: GET/POST and Host.



but the above output is not valid for sending it to a web server. We need some new lines added to it:

# echo ...

Unix shell - using TR to replace new lines with spaces

There are a few ways of replacing new lines with other characters. Below I'll show a few examples for replacing new lines in strings or standard input/output.

Replace new lines with spaces:

# cat test.file
In the first synopsis form, the characters in string1 are translated into
the characters in string2 where the first character in string1 is trans-
lated into the first ...

This article will show only a few example that would be enough for most people:

How to remove multiple white spaces from a string:


How to replace multiple white spaces from a string:


Above sed command replaces multiple spaces with a single space. You can adjust it to replace multiple ...

Even though the Nginx configuration file contains a rewrite rule which is terminated corectly (with ), if a rule contains curly brackets {}, then those brackets finish the location directive in Nginx configuration prematurely, thus making Nginx complaining about line termination.

Example:

[hence the curly brackets in ...