Set shell options in a script or at a global level.

Prevent accidental file overwrites

Copy and move

source

alias cp='cp -i'
alias mv='mv -i'

Redirection

Prevent output redirection using ‘>’, ‘>&’, and ‘<>’ from overwriting existing files. source

set -C

Similar to the above. source

set -o noclobber

When this is on, > file gives an error but >| file seems to force but need to confirm.

Exit on error

  • Using set docs. 
      set -e

  # Reverse it with this:
  set +e
  • In a shebang. Only works with #!/bin/bash and not #!/usr/bin/env bash. 
      #!/bin/bash -e

  echo 'Hello!'
  • Setting the body of the script. 
      #!/usr/bin/env bash

  set -e
  echo 'Hello!'

Verbose

Print a trace of commands before running.

set -x

Or

$ bash -x my_script.sh