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#
# For a description of the syntax of this configuration file,
# see scripts/kbuild/config-language.txt.
#
menu "Shells"
choice
prompt "Choose your default shell"
default FEATURE_SH_IS_ASH
help
Choose a shell. The ash shell is the most bash compatible
and full featured one.
config BUSYBOX_FEATURE_SH_IS_ASH
select BUSYBOX_ASH
bool "ash"
depends on !BUSYBOX_NOMMU
config BUSYBOX_FEATURE_SH_IS_HUSH
select BUSYBOX_HUSH
bool "hush"
####config FEATURE_SH_IS_LASH
#### select LASH
#### bool "lash"
####config FEATURE_SH_IS_MSH
#### select MSH
#### bool "msh"
config BUSYBOX_FEATURE_SH_IS_NONE
bool "none"
endchoice
config BUSYBOX_ASH
bool "ash"
default y
depends on !BUSYBOX_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 BUSYBOX_ASH_BASH_COMPAT
bool "bash-compatible extensions"
default y
depends on BUSYBOX_ASH
help
Enable bash-compatible extensions.
config BUSYBOX_ASH_JOB_CONTROL
bool "Job control"
default y
depends on BUSYBOX_ASH
help
Enable job control in the ash shell.
config BUSYBOX_ASH_ALIAS
bool "alias support"
default y
depends on BUSYBOX_ASH
help
Enable alias support in the ash shell.
config BUSYBOX_ASH_GETOPTS
bool "Builtin getopt to parse positional parameters"
default y
depends on BUSYBOX_ASH
help
Enable getopts builtin in the ash shell.
config BUSYBOX_ASH_BUILTIN_ECHO
bool "Builtin version of 'echo'"
default y
depends on BUSYBOX_ASH
help
Enable support for echo, builtin to ash.
config BUSYBOX_ASH_BUILTIN_PRINTF
bool "Builtin version of 'printf'"
default y
depends on BUSYBOX_ASH
help
Enable support for printf, builtin to ash.
config BUSYBOX_ASH_BUILTIN_TEST
bool "Builtin version of 'test'"
default y
depends on BUSYBOX_ASH
help
Enable support for test, builtin to ash.
config BUSYBOX_ASH_CMDCMD
bool "'command' command to override shell builtins"
default n
depends on BUSYBOX_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 BUSYBOX_ASH_MAIL
bool "Check for new mail on interactive shells"
default n
depends on BUSYBOX_ASH
help
Enable "check for new mail" in the ash shell.
config BUSYBOX_ASH_OPTIMIZE_FOR_SIZE
bool "Optimize for size instead of speed"
default y
depends on BUSYBOX_ASH
help
Compile ash for reduced size at the price of speed.
config BUSYBOX_ASH_RANDOM_SUPPORT
bool "Pseudorandom generator and $RANDOM variable"
default n
depends on BUSYBOX_ASH
help
Enable pseudorandom generator and dynamic variable "$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 BUSYBOX_ASH_EXPAND_PRMT
bool "Expand prompt string"
default y
depends on BUSYBOX_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 BUSYBOX_HUSH
bool "hush"
default n
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 BUSYBOX_HUSH_BASH_COMPAT
bool "bash-compatible extensions"
default y
depends on BUSYBOX_HUSH
help
Enable bash-compatible extensions.
config BUSYBOX_HUSH_HELP
bool "help builtin"
default n
depends on BUSYBOX_HUSH
help
Enable help builtin in hush. Code size + ~1 kbyte.
config BUSYBOX_HUSH_INTERACTIVE
bool "Interactive mode"
default y
depends on BUSYBOX_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 BUSYBOX_HUSH_JOB
bool "Job control"
default n
depends on BUSYBOX_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 BUSYBOX_HUSH_TICK
bool "Process substitution"
default n
depends on BUSYBOX_HUSH
help
Enable process substitution `command` and $(command) in hush.
config BUSYBOX_HUSH_IF
bool "Support if/then/elif/else/fi"
default n
depends on BUSYBOX_HUSH
help
Enable if/then/elif/else/fi in hush.
config BUSYBOX_HUSH_LOOPS
bool "Support for, while and until loops"
default n
depends on BUSYBOX_HUSH
help
Enable for, while and until loops in hush.
config BUSYBOX_HUSH_CASE
bool "Support case ... esac statement"
default n
depends on BUSYBOX_HUSH
help
Enable case ... esac statement in hush. +400 bytes.
config BUSYBOX_HUSH_FUNCTIONS
bool "Support funcname() { commands; } syntax"
default n
depends on BUSYBOX_HUSH
help
Enable support for shell functions in hush. +800 bytes.
config BUSYBOX_HUSH_LOCAL
bool "Support local builtin"
default n
depends on BUSYBOX_HUSH_FUNCTIONS
help
Enable support for local variables in functions.
config BUSYBOX_HUSH_EXPORT_N
bool "Support export '-n' option"
default n
depends on BUSYBOX_HUSH
help
Enable support for export '-n' option in hush. It is a bash extension.
config BUSYBOX_HUSH_RANDOM_SUPPORT
bool "Pseudorandom generator and $RANDOM variable"
default n
depends on BUSYBOX_HUSH
help
Enable pseudorandom generator and dynamic variable "$RANDOM".
Each read of "$RANDOM" will generate a new pseudorandom value.
config BUSYBOX_LASH
bool "lash (deprecated: aliased to hush)"
default n
select BUSYBOX_HUSH
help
lash is deprecated and will be removed, please migrate to hush.
config BUSYBOX_MSH
bool "msh (deprecated: please use hush)"
default n
select BUSYBOX_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 BUSYBOX_SH_MATH_SUPPORT
bool "POSIX math support"
default y
depends on BUSYBOX_ASH || BUSYBOX_HUSH
help
Enable math support in the shell via $((...)) syntax.
config BUSYBOX_SH_MATH_SUPPORT_64
bool "Extend POSIX math support to 64 bit"
default n
depends on BUSYBOX_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 BUSYBOX_FEATURE_SH_EXTRA_QUIET
bool "Hide message on interactive shell startup"
default n
depends on BUSYBOX_MSH || BUSYBOX_LASH || BUSYBOX_HUSH || BUSYBOX_ASH
help
Remove the busybox introduction when starting a shell.
config BUSYBOX_FEATURE_SH_STANDALONE
bool "Standalone shell"
default n
depends on (BUSYBOX_MSH || BUSYBOX_LASH || BUSYBOX_HUSH || BUSYBOX_ASH) && BUSYBOX_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 BUSYBOX_FEATURE_SH_NOFORK
bool "Run 'nofork' applets directly"
default n
depends on (BUSYBOX_MSH || BUSYBOX_LASH || BUSYBOX_HUSH || BUSYBOX_ASH) && BUSYBOX_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 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.
config BUSYBOX_CTTYHACK
bool "cttyhack"
default n
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. Usage example for /etc/inittab
(for busybox init):
::respawn:/bin/cttyhack /bin/sh
endmenu
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