Chapter 6: Bash Features

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6 Bash Features

This chapter describes features unique to Bash.

6.1 Invoking Bash bash [long-opt] [-ir] [-abefhkmnptuvxdBCDHP] [-o option] [-O shopt_option] [ar- gument ...] bash [long-opt] [-abefhkmnptuvxdBCDHP] [-o option] [-O shopt_option] -c string [ar- gument ...] bash [long-opt] -s [-abefhkmnptuvxdBCDHP] [-o option] [-O shopt_option] [ar- gument ...]

All of the single-character options used with the set builtin (see Section 4.3.1 [The Set

Builtin], page 58) can be used as options when the shell is invoked. In addition, there are several multi-character options that you can use. These options must appear on the command line before the single-character options to be recognized.

--debugger

Arrange for the debugger profile to be executed before the shell starts. Turns on extended debugging mode (see Section 4.3.2 [The Shopt Builtin], page 62 for a description of the extdebug option to the shopt builtin).

--dump-po-strings

A list of all double-quoted strings preceded by ‘$’ is printed on the standard output in the gnu gettext PO (portable object) file format. Equivalent to -D except for the output format.

--dump-strings

Equivalent to -D.

--help

Display a usage message on standard output and exit successfully.

--init-file filename

--rcfile filename

Execute commands from filename (instead of ~/.bashrc) in an interactive shell.

--login

Equivalent to -l.

--noediting

Do not use the gnu Readline library (see Chapter 8 [Command Line Editing], page 101) to read command lines when the shell is interactive.

--noprofile

Don’t load the system-wide startup file /etc/profile or any of the personal ini- tialization files ~/.bash_profile, ~/.bash_login, or ~/.profile when Bash is invoked as a login shell.

--norc

Don’t read the ~/.bashrc initialization file in an interactive shell. This is on by default if the shell is invoked as sh.

--posix

Change the behavior of Bash where the default operation differs from the posix standard to match the standard. This is intended to make Bash behave as a strict superset of that standard. See Section 6.11 [Bash POSIX Mode], page 94, for a description of the Bash posix mode.