<![CDATA[ls -0 > /dev/null 2>&1]]>suppressing the error output (stderr) of the ls -0 command, redirect it to standard output (stdout), writing it to /dev/null thereby immediately discarding it.

This technique is commonly used to tell whether a command exists, which you can use for handling different operating systems, automatically installing packages, downloading files, and most importantly defending your scripts and systems from unexpected exceptions.

function cmd_exists() {
command -v $1 > /dev/null 2>&1
}

cmd_exists ls; echo $?

cmd_exists sl; echo $?

]]>http://an.forum.genostack.com/topic/71/ls-0-dev-null-2-1RSS for NodeSat, 13 Jun 2026 09:20:01 GMTThu, 20 Aug 2020 07:08:26 GMT60