Linux/BASH

Shebang

• #!/bin/bash

Output & Piping

• output to file

command > file.txt             # redirect output
command >> file.txt            # append to file

command &> file.txt            # stdout and stderr to file
command &>> file.txt           # stdout and stderr append to file

command 2> file.txt            # stderr to file
command 2>> file.txt           # stderr append to file

command | tee -a file.txt      # stdout to terminal and file (append)
command |& tee -a file.txt     # stdout+stderr to terminal and file (append)

redirecting output

command 2>&1 >/dev/null        # stderr to stdout and stdout to null

If

if [ condition ]
  then command1
  else command2
fi

if [ -f file.txt ]; then echo "file exists"; fi

For loop

for OUTPUT in $(linuxcommand)
do
	command1 on $OUTPUT
	command2 on $OUTPUT
	commandN
done

Links

• https://devhints.io/bash
• http://tldp.org/LDP/abs/html/special-chars.html
• http://tldp.org/LDP/abs/html/internalvariables.html
• http://wiki.laub-home.de/index.php/Shell_Skripte_-_What_to_know_about
• http://wiki.laub-home.de/index.php/Shell_Skripte_-_eine_kleine_Sammlung
• http://www.pantz.org/software/shell/shelloneliners.html