shell/Config.src

#
# For a description of the syntax of this configuration file,
# see scripts/kbuild/config-language.txt.
#

menu "Shells"

INSERT


choice
	prompt "Choose which shell is aliased to 'sh' name"
	default FEATURE_SH_IS_ASH
	help
	  Choose which shell you want to be executed by 'sh' alias.
	  The ash shell is the most bash compatible and full featured one.

# note: cannot use "select ASH" here, it breaks "make allnoconfig"
config FEATURE_SH_IS_ASH
	depends on ASH
	bool "ash"
	depends on !NOMMU

config FEATURE_SH_IS_HUSH
	depends on HUSH
	bool "hush"

config FEATURE_SH_IS_NONE
	bool "none"

endchoice

choice
	prompt "Choose which shell is aliased to 'bash' name"
	default FEATURE_BASH_IS_NONE
	help
	  Choose which shell you want to be executed by 'bash' alias.
	  The ash shell is the most bash compatible and full featured one.

	  Note that selecting this option does not switch on any bash
	  compatibility code. It merely makes it possible to install
	  /bin/bash (sym)link and run scripts which start with
	  #!/bin/bash line.

	  Many systems use it in scripts which use bash-specific features,
	  even simple ones like $RANDOM. Without this option, busybox
	  can't be used for running them because it won't recongnize
	  "bash" as a supported applet name.

config FEATURE_BASH_IS_ASH
	depends on ASH
	bool "ash"
	depends on !NOMMU

config FEATURE_BASH_IS_HUSH
	depends on HUSH
	bool "hush"

config FEATURE_BASH_IS_NONE
	bool "none"

endchoice


config SH_MATH_SUPPORT
	bool "POSIX math support"
	default y
	depends on ASH || HUSH
	help
	  Enable math support in the shell via $((...)) syntax.

config SH_MATH_SUPPORT_64
	bool "Extend POSIX math support to 64 bit"
	default y
	depends on SH_MATH_SUPPORT
	help
	  Enable 64-bit math support in the shell. This will make the shell
	  slightly larger, but will allow computation with very large numbers.
	  This is not in POSIX, so do not rely on this in portable code.

config FEATURE_SH_EXTRA_QUIET
	bool "Hide message on interactive shell startup"
	default y
	depends on HUSH || ASH
	help
	  Remove the busybox introduction when starting a shell.

config FEATURE_SH_STANDALONE
	bool "Standalone shell"
	default n
	depends on (HUSH || ASH) && FEATURE_PREFER_APPLETS
	help
	  This option causes busybox shells to use busybox applets
	  in preference to executables in the PATH whenever possible. For
	  example, entering the command 'ifconfig' into the shell would cause
	  busybox to use the ifconfig busybox applet. Specifying the fully
	  qualified executable name, such as '/sbin/ifconfig' will still
	  execute the /sbin/ifconfig executable on the filesystem. This option
	  is generally used when creating a statically linked version of busybox
	  for use as a rescue shell, in the event that you screw up your system.

	  This is implemented by re-execing /proc/self/exe (typically)
	  with right parameters. Some selected applets ("NOFORK" applets)
	  can even be executed without creating new process.
	  Instead, busybox will call <applet>_main() internally.

	  However, this causes problems in chroot jails without mounted /proc
	  and with ps/top (command name can be shown as 'exe' for applets
	  started this way).
# untrue?
#	  Note that this will *also* cause applets to take precedence
#	  over shell builtins of the same name. So turning this on will
#	  eliminate any performance gained by turning on the builtin "echo"
#	  and "test" commands in ash.
# untrue?
#	  Note that when using this option, the shell will attempt to directly
#	  run '/bin/busybox'. If you do not have the busybox binary sitting in
#	  that exact location with that exact name, this option will not work at
#	  all.

config FEATURE_SH_NOFORK
	bool "Run 'nofork' applets directly"
	default n
	depends on (HUSH || ASH) && FEATURE_PREFER_APPLETS
	help
	  This option causes busybox shells to not execute typical
	  fork/exec/wait sequence, but call <applet>_main directly,
	  if possible. (Sometimes it is not possible: for example,
	  this is not possible in pipes).

	  This will be done only for some applets (those which are marked
	  NOFORK in include/applets.h).

	  This may significantly speed up some shell scripts.

	  This feature is relatively new. Use with care. Report bugs
	  to project mailing list.

endmenu