bash Cookbook, 2nd Edition

Appendix A. Reference Lists

This appendix collects many tables of values, settings, operators, commands, variables, and more in one place for easy reference.

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 usually have the options -i (interactive), -s (read from standard input), and -m (enable job control) set internally.

In addition to those listed in Table A-1, any set option can be used on the command line; see “set Options”. In particular, the -n option is invaluable for syntax checking (see Recipe 19.12), and -x is used for debugging (Recipe 19.13).

For further reference, see http://bit.ly/2wtEjA8.

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 written to 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	Makes the shell an 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 it were invoked as a login shell.
-o option	Takes the same arguments as set -o (see “set Options”).
-O, +O shopt-option	shopt-option ...