Table B-7. Options to set
Option | Full name | Meaning |
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-a | allexport | Export all subsequently defined or modified variables. |
-B | braceexpand | The shell performs brace expansion. This is on by default. |
-b | notify | Report the status of terminating background jobs immediately. |
-C | noclobber | Don't allow redirection to overwrite existing files. |
-E | errtrace | Any trap on ERR is inherited by shell functions, command substitutions, and commands executed in a subshell environment. |
-e | errexit | Exit the shell when a simple command exits with non-zero status. A simple command is a command not part of a while, until, or if; or part of a && or || list; or a command whose return value is inverted by !. |
| emacs | Use emacs-style command-line editing. |
-f | noglob | Disable pathname expansion. |
-H | histexpand | Enable ! style history substitution. On by default in an interactive shell. |
| history | Enable command history. On by default in interactive shells. |
-h | hashall | Disable the hashing of commands. |
| ignoreeof | Disallow CTRL-D to exit the shell. |
-k | keyword | Place keyword arguments in the environment for a command. |
-m | monitor | Enable job control (on by default in interactive shells). |
-n | noexec | Read commands and check syntax but do not execute them. Ignored for interactive shells. |
-P | physical | Do not follow symbolic links on commands that change the current directory. Use the physical directory. |
-p | privileged | Script is running in suid mode. |
| pipefail | The return value of a pipeline is the value of the last (rightmost) command to exit with a non-zero status, or zero if all commands in the pipeline exit successfully. This option is disabled by default. |
| posix | Change the default behavior to that of POSIX 1003.2 where it differs from the standard. |
-T | functrace | Any trap on DEBUG is inherited by shell functions, command substitutions, and commands executed in a subshell environment. |
-t | onecmd | Exit after reading and executing one command. |
-u | nounset | Treat undefined variables as errors, not as null. |
-v | verbose | Print shell input lines before running them. |
| vi | Use vi-style command-line editing. |
-x | xtrace | Print commands (after expansions) before running them. |
- | | Signals the end of options. All remaining arguments are assigned to the positional parameters. -x and -v are turned off. If there are no remaining arguments to set, the positional arguments remain unchanged. |
| | With no arguments following, unset the positional parameters. Otherwise, the positional parameters are set to the following arguments (even if they begin with -). |