klimbim/bash/detect-if-installed.sh

#!/bin/bash

# Klimbim Software collection, A bag full of things
# Copyright (C) 2011-2023 Johannes 'Banana' Keßler
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <https://www.gnu.org/licenses/>.

# 2019 https://www.bananas-playground.net
# Simple example how to detect if a command is available
# otherwise print message and exit

# In this example we need curl to be iinstalled.
# If not print message and exit.
command -v curl >/dev/null 2>&1 || { echo >&2 "I require curl (https://curl.haxx.se/) but it's not installed.  Aborting."; exit 1; }