bash Cookbook

bash Invocation

Here are the options you can use when invoking current versions of bash. The multi-character options must appear on the command line before the single-character options. Login shells are usually invoked with the options -i (interactive), -s (read from standard input), and -m (enable job control).

In addition to these listed in Table A-1, any set option can be used on the command line; see the “set Options” section later in this chapter. In particular, the -n option is invaluable for syntax checking, see Testing bash Script Syntax.

Table A-1. Command-line options to bash

Option	Meaning
-c string	Commands are read from string, if present. Any arguments after string are interpreted as positional parameters, starting with $0.
-D	A list of all double-quoted strings preceded by $ is printed on the standard output. These are the strings that are subject to language translation when the current locale is not C or POSIX. This also turns on the -n option.
-i	Interactive shell. Ignores signals TERM, INT, and QUIT. With job control in effect, TTIN, TTOU, and TSTP are also ignored.
-l	Makes bash act as if invoked as a login shell.
-o option	Takes the same arguments as set -o.
O, +O shopt-option	shopt-option is one of the shell options accepted by the shopt built-in. If shopt-option is present, -O sets the value of that option; +O unsets it. If shopt-option is not supplied, the names and values of the shell options accepted by shopt are printed on the standard output. If the invocation ...