• Skip to main content

Uly.me

cloud engineer

  • Home
  • Archives
  • Search

Bash Variable Empty

August 6, 2021 by Ulysses

Here’s how to check in Bash if a variable is empty or unset.

if [ -z "${VAR}" ]; 
then
  echo 'do something'
else
  echo 'do another'
fi

if [ -z "${VAR}" ]; then echo 'do something' else echo 'do another' fi

One liner

if [ -z "${VAR}" ]; then echo 'do something'; else echo 'do another'; fi

if [ -z "${VAR}" ]; then echo 'do something'; else echo 'do another'; fi

The inverse

if [ ! -z "${VAR}" ]; 
then
  echo 'do something'
else
  echo 'do another'
fi

if [ ! -z "${VAR}" ]; then echo 'do something' else echo 'do another' fi

if [ ! -z "${VAR}" ]; then echo 'do something'; else echo 'do another'; fi

if [ ! -z "${VAR}" ]; then echo 'do something'; else echo 'do another'; fi

Filed Under: Linux Tagged With: bash, check, empty, unset, variable

Search The Website

Subscribe Via Email

  • Home
  • About
  • Contact

Copyright © 2022