menu "Shells"
-config ASH
- bool "ash"
- default y
- depends on !NOMMU
- help
- Tha 'ash' shell adds about 60k in the default configuration and is
- the most complete and most pedantically correct shell included with
- busybox. This shell is actually a derivative of the Debian 'dash'
- shell (by Herbert Xu), which was created by porting the 'ash' shell
- (written by Kenneth Almquist) from NetBSD.
-
-config ASH_BASH_COMPAT
- bool "bash-compatible extensions"
- default y
- depends on ASH
- help
- Enable bash-compatible extensions.
-
-config ASH_JOB_CONTROL
- bool "Job control"
- default y
- depends on ASH
- help
- Enable job control in the ash shell.
-
-config ASH_ALIAS
- bool "alias support"
- default y
- depends on ASH
- help
- Enable alias support in the ash shell.
-
-config ASH_GETOPTS
- bool "Builtin getopt to parse positional parameters"
- default y
- depends on ASH
- help
- Enable getopts builtin in the ash shell.
-
-config ASH_BUILTIN_ECHO
- bool "Builtin version of 'echo'"
- default y
- depends on ASH
- help
- Enable support for echo, builtin to ash.
-
-config ASH_BUILTIN_PRINTF
- bool "Builtin version of 'printf'"
- default y
- depends on ASH
- help
- Enable support for printf, builtin to ash.
-
-config ASH_BUILTIN_TEST
- bool "Builtin version of 'test'"
- default y
- depends on ASH
- help
- Enable support for test, builtin to ash.
-
-config ASH_CMDCMD
- bool "'command' command to override shell builtins"
- default y
- depends on ASH
- help
- Enable support for the ash 'command' builtin, which allows
- you to run the specified command with the specified arguments,
- even when there is an ash builtin command with the same name.
-
-config ASH_MAIL
- bool "Check for new mail on interactive shells"
- default n
- depends on ASH
- help
- Enable "check for new mail" in the ash shell.
-
-config ASH_OPTIMIZE_FOR_SIZE
- bool "Optimize for size instead of speed"
- default y
- depends on ASH
- help
- Compile ash for reduced size at the price of speed.
-
-config ASH_RANDOM_SUPPORT
- bool "Pseudorandom generator and $RANDOM variable"
- default y
- depends on ASH
- help
- Enable pseudorandom generator and dynamic variable "$RANDOM".
- Each read of "$RANDOM" will generate a new pseudorandom value.
- You can reset the generator by using a specified start value.
- After "unset RANDOM" the generator will switch off and this
- variable will no longer have special treatment.
-
-config ASH_EXPAND_PRMT
- bool "Expand prompt string"
- default y
- depends on ASH
- help
- "PS#" may contain volatile content, such as backquote commands.
- This option recreates the prompt string from the environment
- variable each time it is displayed.
-
-config HUSH
- bool "hush"
- default y
- help
- hush is a small shell (22k). It handles the normal flow control
- constructs such as if/then/elif/else/fi, for/in/do/done, while loops,
- case/esac. Redirections, here documents, $((arithmetic))
- and functions are supported.
-
- It will compile and work on no-mmu systems.
-
- It does not handle select, aliases, brace expansion,
- tilde expansion, &>file and >&file redirection of stdout+stderr.
-
-config HUSH_BASH_COMPAT
- bool "bash-compatible extensions"
- default y
- depends on HUSH
- help
- Enable bash-compatible extensions.
-
-config HUSH_HELP
- bool "help builtin"
- default y
- depends on HUSH
- help
- Enable help builtin in hush. Code size + ~1 kbyte.
-
-config HUSH_INTERACTIVE
- bool "Interactive mode"
- default y
- depends on HUSH
- help
- Enable interactive mode (prompt and command editing).
- Without this, hush simply reads and executes commands
- from stdin just like a shell script from a file.
- No prompt, no PS1/PS2 magic shell variables.
-
-config HUSH_JOB
- bool "Job control"
- default y
- depends on HUSH_INTERACTIVE
- help
- Enable job control: Ctrl-Z backgrounds, Ctrl-C interrupts current
- command (not entire shell), fg/bg builtins work. Without this option,
- "cmd &" still works by simply spawning a process and immediately
- prompting for next command (or executing next command in a script),
- but no separate process group is formed.
-
-config HUSH_TICK
- bool "Process substitution"
- default y
- depends on HUSH
- help
- Enable process substitution `command` and $(command) in hush.
-
-config HUSH_IF
- bool "Support if/then/elif/else/fi"
- default y
- depends on HUSH
- help
- Enable if/then/elif/else/fi in hush.
-
-config HUSH_LOOPS
- bool "Support for, while and until loops"
- default y
- depends on HUSH
- help
- Enable for, while and until loops in hush.
-
-config HUSH_CASE
- bool "Support case ... esac statement"
- default y
- depends on HUSH
- help
- Enable case ... esac statement in hush. +400 bytes.
-
-config HUSH_FUNCTIONS
- bool "Support funcname() { commands; } syntax"
- default y
- depends on HUSH
- help
- Enable support for shell functions in hush. +800 bytes.
-
-config HUSH_LOCAL
- bool "Support local builtin"
- default y
- depends on HUSH_FUNCTIONS
- help
- Enable support for local variables in functions.
-
-config HUSH_EXPORT_N
- bool "Support export '-n' option"
- default y
- depends on HUSH
- help
- Enable support for export '-n' option in hush. It is a bash extension.
-
-config HUSH_RANDOM_SUPPORT
- bool "Pseudorandom generator and $RANDOM variable"
- default y
- depends on HUSH
- help
- Enable pseudorandom generator and dynamic variable "$RANDOM".
- Each read of "$RANDOM" will generate a new pseudorandom value.
+INSERT
choice
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 "amke allnoconfig"
+# note: cannot use "select ASH" here, it breaks "make allnoconfig"
config FEATURE_SH_IS_ASH
depends on ASH
bool "ash"
endchoice
-config LASH
- bool "lash (deprecated: aliased to hush)"
- default n
- select HUSH
- help
- lash is deprecated and will be removed, please migrate to hush.
-
-config MSH
- bool "msh (deprecated: please use hush)"
- default n
- select HUSH
- help
- msh is deprecated and will be removed, please migrate to hush.
- If there is a feature msh has but hush does not, please let us know.
-
-# The minix shell (adds just 30k) is quite complete and handles things
-# like for/do/done, case/esac and all the things you expect a Bourne
-# shell to do. It is not always pedantically correct about Bourne
-# shell grammar (try running the shell testscript "tests/sh.testcases"
-# on it and compare vs bash) but for most things it works quite well.
-# It uses only vfork, so it can be used on uClinux systems.
-
-
config SH_MATH_SUPPORT
bool "POSIX math support"
default y
default n
depends on (HUSH || ASH) && FEATURE_PREFER_APPLETS
help
- This option causes busybox shells [currently only ash]
- to not execute typical fork/exec/wait sequence, but call <applet>_main
- directly, if possible. (Sometimes it is not possible: for example,
+ 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
This may significantly speed up some shell scripts.
- This feature is relatively new. Use with care.
+ This feature is relatively new. Use with care. Report bugs
+ to project mailing list.
-config CTTYHACK
- bool "cttyhack"
+config FEATURE_SH_HISTFILESIZE
+ bool "Use $HISTFILESIZE"
default y
+ depends on HUSH || ASH
help
- One common problem reported on the mailing list is "can't access tty;
- job control turned off" error message which typically appears when
- one tries to use shell with stdin/stdout opened to /dev/console.
- This device is special - it cannot be a controlling tty.
-
- Proper solution is to use correct device instead of /dev/console.
-
- cttyhack provides "quick and dirty" solution to this problem.
- It analyzes stdin with various ioctls, trying to determine whether
- it is a /dev/ttyN or /dev/ttySN (virtual terminal or serial line).
- If it detects one, it closes stdin/out/err and reopens that device.
- Then it executes given program. Opening the device will make
- that device a controlling tty. This may require cttyhack
- to be a session leader.
-
- Example for /etc/inittab (for busybox init):
-
- ::respawn:/bin/cttyhack /bin/sh
-
- Giving controlling tty to shell running with PID 1:
-
- $ exec cttyhack sh
-
- Starting an interactive shell from boot shell script:
+ This option makes busybox shells to use $HISTFILESIZE variable
+ to set shell history size. Note that its max value is capped
+ by "History size" setting in library tuning section.
- setsid cttyhack sh
endmenu