This article talks about the builtin command utility command. To know what a command means in the context of bash, see What is a Command in Bash?
The command function suppress the the shell function lookup in the search command order.
For command as a bash definition, see What is a Command in Bash?.
command [-pVv] command [arg ...]
where:
If either the V or v option is supplied, a description of command is printed.
have_command () {
command -v "$1" >/dev/null 2>/dev/null
}
require_command () {
if ! have_command "$1"; then
die 1 "Could not find required command '$1' in system PATH. Aborting."
fi
}