set - command syntax

set [options] [arguments]

In the context of the set command, [options] are
settings or flags that are set or unset in the
Bash shell environment. Use it to influence the
behavior of defined shell scripts and help execute
the desired tasks.

• Set an option by using a minus sign (-) followed by the appropriate option.
• Unset an option by using a plus sign (+) followed by the appropriate option.

Options

• -m Displays a message when a task completes.
• -x Prints out command arguments during execution.
• -a Marks all created or modified variables or functions for export.
• -e Instructs a shell to exit if a command fails, i.e., if it outputs a non-zero exit status.
• -u Treats unset or undefined variables as an error when substituting.
• -b Alerts the user upon background job termination.