If you read the man page for bash
you’ll find the following at the top of the OPTIONS
section:
All of the single-character shell options documented in the description of the set builtin command can be used as options when the shell is invoked. In addition, bash interprets the following options when it is invoked...
And if you read the documentation for the set
command later on in the man page, you’ll find:
-e Exit immediately if a pipeline (which may consist of a single simple command), a subshell command enclosed in parentheses, or one of the commands executed as part of a command list enclosed by braces (see SHELL GRAMMAR above) exits with a non-zero status. -x After expanding each simple command, for command, case command, select command, or arithmetic for command, display the expanded value of PS4, followed by the command and its expanded arguments or associated word list.
In other words, -e
makes the shell exit immediately whenever
something returns an error (this is often used in shell scripts as a
failsafe mechanism), and -x
enables verbose execution of scripts so
that you can see what’s happening.