blog/content/administration/bash.md

Title	date	Author	Draft	Categories	Tags	Truncated
Bash Tips & Tricks	2018-11-11T16:01:15+01:00	Olivier De Ram	false	[administration development]	[bash script]	true

Usefull bash tips & tricks

Usefull CLI shortcuts:

Shortcut	Description
Ctrl+a	Jump to the beginning of the command line.
Ctrl+e	Jump to the end of the command line.
Ctrl+u	Clear from the cursor to the beginning of the command line.
Ctrl+k	Clear from the cursor to the end of the command line.
Ctrl+Left Arrow	Jump to the beginning of the previous word on the command line.
Ctrl+Right Arrow	Jump to the end of the next word on the command line.
Ctrl+r	Search the history list of commands for a pattern.
Esc + .	Copy the last word of the previous command on the current command line where the cursor is

Redirect output:

Command	result
> file	redirect stdout to overwrite a file
>> file	redirect stdout to append to a file
2> file	redirect stderr to overwrite a file
2> /dev/null	discard stderr error messages by redirecting to /dev/null
&> file (OR > file 2>&1)	redirect stdout and stderr to overwrite the same file
&>> (OR >> file 2>&1)	redirect stdout and stderr to append to the same file

Create a function:

It's straightforward, use function to create a function, give it a usefull short name and put the statemants between curly brackets.
Use $1 for the first argument, $2 for the second argument and so on...

function <name> {
	<bashcommands>
}

For example the function logsearch which searches for the given string whitin all logfiles in the current directory:

function logsearch {
	zgrep $1 ./*log
}

Short scripts:

• Loop every file in path:

for F in /path/to/files/*;
do
	echo "Files $F";
done

• Loop file line per line:

while read LINE;
do
	echo $LINE;
done < file.txt