GWAK

Arnold Robbins, an Atlanta native, is a professional programmer and technical author.

He has been a heavy AWK user since 1987, when he became involved with gawk, the GNU project’s version of AWK.

Sed

Add item to certain line

sed -i '20 a nouvel élèment' FICHIER

Remove saut de ligne

sed '/^$/d'

sed '/^:space:*$/d'

AWK

Awk command :

TR

Remove space :

tr -d '[:blank:]'

FIND

Files

Find all ‘jacquet’ file from $PLACE :

find $PLACE -name "jacquet"

Directory

Find all files older than 90 days in /var/log/httpd/ directory

find /var/log/httpd/ -type f -name "*" -mtime +90 -exec rm -f {} \;

Exclude

How to exclude directory.ies ?

Use the ! -path '*$THING*'syntax

find $PLACE -type f -name $SOMETING ! -path '*NOT_THIS_ONE*'

Grep

That is a command-line utility for searching plain-text data sets for lines that match a regular expression.

Its name comes from the ed command g/re/p (globally search for a regular expression and print matching lines).

grep thing file.txt
grep "searching elements" -A $NUMBER_OF_LINE -B $NUMBER_OF_LINE

Catch something from multiple files

grep -ari copyright /var/www/html/