cttyhack: move build system bits into cttyhack.c, no code changes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

shell/Config.src

@@ -158,40 +158,4 @@ config FEATURE_SH_NOFORK
 
 	  This feature is relatively new. Use with care.
 
-config CTTYHACK
-	bool "cttyhack"
-	default y
-	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
-
-	  Starting an interactive shell from boot shell script:
-
-	  setsid cttyhack sh
-
-	  Giving controlling tty to shell running with PID 1:
-
-	  # exec cttyhack sh
-
-	  Without cttyhack, you need to know exact tty name,
-	  and do something like this:
-
-	  # exec setsid sh -c 'exec sh </dev/tty1 >/dev/tty1 2>&1'
-
 endmenu

shell/Kbuild.src

@@ -8,5 +8,4 @@ lib-y:=
 
 INSERT
 
-lib-$(CONFIG_CTTYHACK) += cttyhack.o
 lib-$(CONFIG_SH_MATH_SUPPORT) += math.o

shell/ash.c

@@ -179,6 +179,7 @@
 //config:	  "PS#" may contain volatile content, such as backquote commands.
 //config:	  This option recreates the prompt string from the environment
 //config:	  variable each time it is displayed.
+//config:
 
 //usage:#define ash_trivial_usage NOUSAGE_STR
 //usage:#define ash_full_usage ""

shell/cttyhack.c

@@ -6,6 +6,58 @@
  */
 #include "libbb.h"
 
+//applet:IF_CTTYHACK(APPLET(cttyhack, _BB_DIR_BIN, _BB_SUID_DROP))
+
+//kbuild:lib-$(CONFIG_CTTYHACK) += cttyhack.o
+
+//config:config CTTYHACK
+//config:	bool "cttyhack"
+//config:	default y
+//config:	help
+//config:	  One common problem reported on the mailing list is "can't access tty;
+//config:	  job control turned off" error message which typically appears when
+//config:	  one tries to use shell with stdin/stdout opened to /dev/console.
+//config:	  This device is special - it cannot be a controlling tty.
+//config:
+//config:	  Proper solution is to use correct device instead of /dev/console.
+//config:
+//config:	  cttyhack provides "quick and dirty" solution to this problem.
+//config:	  It analyzes stdin with various ioctls, trying to determine whether
+//config:	  it is a /dev/ttyN or /dev/ttySN (virtual terminal or serial line).
+//config:	  If it detects one, it closes stdin/out/err and reopens that device.
+//config:	  Then it executes given program. Opening the device will make
+//config:	  that device a controlling tty. This may require cttyhack
+//config:	  to be a session leader.
+//config:
+//config:	  Example for /etc/inittab (for busybox init):
+//config:
+//config:	  ::respawn:/bin/cttyhack /bin/sh
+//config:
+//config:	  Starting an interactive shell from boot shell script:
+//config:
+//config:	  setsid cttyhack sh
+//config:
+//config:	  Giving controlling tty to shell running with PID 1:
+//config:
+//config:	  # exec cttyhack sh
+//config:
+//config:	  Without cttyhack, you need to know exact tty name,
+//config:	  and do something like this:
+//config:
+//config:	  # exec setsid sh -c 'exec sh </dev/tty1 >/dev/tty1 2>&1'
+//config:
+
+//usage:#define cttyhack_trivial_usage
+//usage:       "PROG ARGS"
+//usage:#define cttyhack_full_usage "\n\n"
+//usage:       "Give PROG a controlling tty if possible."
+//usage:     "\nExample for /etc/inittab (for busybox init):"
+//usage:     "\n	::respawn:/bin/cttyhack /bin/sh"
+//usage:     "\nGiving controlling tty to shell running with PID 1:"
+//usage:     "\n	$ exec cttyhack sh"
+//usage:     "\nStarting interactive shell from boot shell script:"
+//usage:     "\n	setsid cttyhack sh"
+
 /* From <linux/vt.h> */
 struct vt_stat {
 	unsigned short v_active;        /* active vt */