Bash Scripting

command interpreter / shell

return to previous dir
cd -

move to some-dir and return at any moment

pushd <some-dir>
popd

move to background, and bring up again

Ctrl + Z
fg

reverse search through history
Ctrl + R

add timestamp to history. Ignore commands if started by whitespace

vim ~/.bashrc
HISTTIMEFORMAT="%Y-%m-%d %T "
HISTCONTROL=ignoreboth

run 2 commands in a row
ls -l; echo "i am the second command"

only run second command if first succeeds
ls -l && echo "i am the second command"

follow log-file in real-time
tail -f <some-log-file>

delete content of file
truncate -s 0 <some-file>

ensure output is columnized
mount | column -t

find out which shell is used from a given terminal window
: echo $SHELL

find the location of bash
: which bash

create file vim some_file.sh

add shebang to top of file #!/usr/env/bin bash

make the file executable sudo chmod +x some_file.sh

variables

if statements

while loops

math functions

exit codes

for loops

functions

case statements

scheduling jobs

arguments