Linux

Linux chmod parameters explained

How to use chmod in Linux. chmod u+ = assign user permissions chmod g+ = assign group permissions chmod a+ = assign all permissions Some examples: Command: chmod u+wrx testfile.txt Result: -rwx—— 1 root root 0 Feb 5 16:53 testfile.txt Command: chmod g+wrx testfile.txt Result: —-rwx— 1 root root 0 Feb 5 16:53 testfile.txt Command: […]

Linux

Handy one line SED command howto

————————————————————————- HANDY ONE-LINERS FOR SED (Unix stream editor) Apr. 26, 2004 compiled by Eric Pement – pemente[at]northpark[dot]edu version 5.4 Latest version of this file is usually at: http://sed.sourceforge.net/sed1line.txt http://www.student.northpark.edu/pemente/sed/sed1line.txt This file is also available in Portuguese at: http://www.lrv.ufsc.br/wmaker/sed_ptBR.html FILE SPACING: # double space a file sed G # double space a file which already has […]

Linux

How to debug Postfix

Postfix DEBUGGING 1.) If things are acting strangely here is a simple and quick first step that could save you a lot of time. * TO CHECK THE CURRENT CONFIGURATION: /usr/sbin/postfix check * validates the Postfix mail system configuration and will * warn about bad directory/file ownership or permissions, and * create missing directories. 2.) […]