# The shopt builtin command

The `shopt` builtin manages [shell options](/internals/shell_options.md), a
set of boolean (`on`/`off`) configuration variables that control the
behaviour of the shell.

## Synopsis

    shopt [-pqsu] [-o] <OPTNAME...>

## Description

Note: Some of these options and other shell options can also be set with
[the set builtin](/commands/builtin/set.md).

### Options

| Option | Description                                                                                                              |
|--------|--------------------------------------------------------------------------------------------------------------------------|
| `-o`   | Restrict the values of `<OPTNAME...>` to only those also known by [the set builtin](/commands/builtin/set.md)               |
| `-p`   | Print all shell options and their current value. **Default**.                                                            |
| `-q`   | Quiet mode. Set exit code if named option is set. For multiple options: `TRUE` if all options are set, `FALSE` otherwise |
| `-s`   | Enable (<u>s</u>et) the shell options named by `<OPTNAME...>` or list all *enabled* options if no names are given        |
| `-u`   | Disabe (<u>u</u>nset) the shell options named by `<OPTNAME...>` or list all *disabled* options if no names are given     |

As noted above, if only `-s` or `-u` are given without any option names,
only the currently enabled (`-s`) or disabled (`-u`) options are
printed.

### Exit code

When listing options, the exit code is `TRUE` (0), if all options are
enabled, `FALSE` otherwise.

When setting/unsetting an option, the exit code is `TRUE` unless the
named option doesn't exitst.

## Examples

Enable the `nullglob` option:

    shopt -s nullglob

## Portability considerations

The `shopt` command is not portable accross different shells.

## See also

- Internal: [The set builtin command](/commands/builtin/set.md)
- Internal: [List of shell options](/internals/shell_options.md)