Disk Usage command

Sometimes it’s useful to be able to find out how much disk space a directory is taking. While there are some web interfaces or desktop applications that allows you to do that, it’s always useful to know how it can be done through a command shell.
The DU Command

To find out how much space is being used, you can use the DU (Disk Usage) command. Here a few examples of the DU command usage.

Listing a disk space summary of directory

 # du -sh [directory]

Listing the disk space used for a directory and its subdirectories, sorted by disk usage

 # du -h [directory] | sort -rn

Take note that the “h” switch allows displays the disk usage in human readable format (ie. kylobytes, megabytes, etc.).

Using Screen To Work Remotely

Screen is a Linux tool that allows you to keep your session alive in case your disconnected. Once you gain back remote access to your server, you can “reattach” yourself to your previous session.

Continue reading →

crontab

allows tasks to be automatically run in the background at regular intervals. You could also use it to automatically create backups, synchronize files, schedule updates, and much more.

run :

sudo crontab -e

This will open the crontab using the default editor.

Here is the format to add cronjobs:

* * * * * /bin/execute/this/script.sh

Continue reading →

grep command

The grep program is a standard UNIX utility that searches through a set of files for an arbitrary text pattern, specified through a regular expression. By default, grep is case-sensitive (use -i to ignore case). By default, grep ignores the context of a string (use -w to match words only). By default, grep shows the lines that match (use -v to show those that don’t match).

Continue reading →