if

Performs conditional processing in shell scripts. See also: test, [. More information: <https://www.gnu.org/software/bash/manual/bash.html#Conditional-Constructs>.

Install

All systems
curl cmd.cat/if.sh
Debian Debian
apt-get install execline
Ubuntu
apt-get install execline
Alpine
apk add execline
image/svg+xml Kali Linux
apt-get install execline
Windows (WSL2)
sudo apt-get update sudo apt-get install execline
Dockerfile
dockerfile.run/if
Docker
docker run cmd.cat/if if powered by Commando

Performs conditional processing in shell scripts. See also: test, [. More information: <https://www.gnu.org/software/bash/manual/bash.html#Conditional-Constructs>.

  • Execute the specified commands if the condition command's exit status is zero:
    if condition_command; then echo "Condition is true"; fi
  • Execute the specified commands if the condition command's exit status is not zero:
    if ! condition_command; then echo "Condition is true"; fi
  • Execute the first specified commands if the condition command's exit status is zero otherwise execute the second specified commands:
    if condition_command; then echo "Condition is true"; else echo "Condition is false"; fi
  • Check whether a [f]ile exists:
    if [[ -f path/to/file ]]; then echo "Condition is true"; fi
  • Check whether a [d]irectory exists:
    if [[ -d path/to/directory ]]; then echo "Condition is true"; fi
  • Check whether a file or directory [e]xists:
    if [[ -e path/to/file_or_directory ]]; then echo "Condition is true"; fi
  • Check whether a variable is defined:
    if [[ -n "$variable" ]]; then echo "Condition is true"; fi
  • List all possible conditions (`test` is an alias to `[`; both are commonly used with `if`):
    man [

© tl;dr; authors and contributors