Check if a Program Exists From Your Bash Script

Lately I’ve had the Bash bug… and I’m continually impressed at what can be accomplished with this tool. Just the other day, I needed to check for the existence of some programs before doing the rest of my scripting work.

Originally I was doing this with which, but after reading this detailed stackoverflow answer, I’m now using the more portable command -v.

Code #

PROGRAM="foo"

if ! command -v ${PROGRAM} >/dev/null; then
  echo "This script requires ${PROGRAM} to be installed and on your PATH ..."
  exit 1
fi

Output #

$ ./script.sh
This script requires foo to be installed and on your PATH ...

$ echo ${?}
1