Each Linux command returns an exit code, with 0 indicating success and non-zero values indicating failure. You can use the $? variable to access the exit code and control program flow in scripts.

Whenever you run a command in a Linux terminal, a numeric exit code is generated – even if you see no sign of it. The code reports the success or failure of the command. And, if the command ...

Viewing exit codes First, it’s important to remember that a successful exit code (a.k.a. “return code”) on Linux systems is 0. Think of this as meaning “zero errors”.

Under certain conditions, attackers can chain a set of vulnerabilities in multiple components of the CUPS open-source printing system to execute arbitrary code remotely on vulnerable machines ...

Spooling Although the at command has the batch alias, it isn’t a complete batch system. However, there are several batch systems for Linux with different attributes.