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authorDenys Vlasenko <vda.linux@googlemail.com>2010-07-16 17:16:40 +0200
committerDenys Vlasenko <vda.linux@googlemail.com>2010-07-16 17:16:40 +0200
commit51ca7761a3579f3c3f7e771b39019e6e248a5171 (patch)
tree04621b8f401e5a478070e633fb2c086c05c99695 /shell
parent5d26df6497505e8ed486bf3e3ba65d0d6f0daa15 (diff)
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cttyhack: move build system bits into cttyhack.c, no code changes
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Diffstat (limited to 'shell')
-rw-r--r--shell/Config.src36
-rw-r--r--shell/Kbuild.src1
-rw-r--r--shell/ash.c1
-rw-r--r--shell/cttyhack.c52
4 files changed, 53 insertions, 37 deletions
diff --git a/shell/Config.src b/shell/Config.src
index 6389d943a..f6f0b6c94 100644
--- a/shell/Config.src
+++ b/shell/Config.src
@@ -158,40 +158,4 @@ config FEATURE_SH_NOFORK
158 158
159 This feature is relatively new. Use with care. 159 This feature is relatively new. Use with care.
160 160
161config CTTYHACK
162 bool "cttyhack"
163 default y
164 help
165 One common problem reported on the mailing list is "can't access tty;
166 job control turned off" error message which typically appears when
167 one tries to use shell with stdin/stdout opened to /dev/console.
168 This device is special - it cannot be a controlling tty.
169
170 Proper solution is to use correct device instead of /dev/console.
171
172 cttyhack provides "quick and dirty" solution to this problem.
173 It analyzes stdin with various ioctls, trying to determine whether
174 it is a /dev/ttyN or /dev/ttySN (virtual terminal or serial line).
175 If it detects one, it closes stdin/out/err and reopens that device.
176 Then it executes given program. Opening the device will make
177 that device a controlling tty. This may require cttyhack
178 to be a session leader.
179
180 Example for /etc/inittab (for busybox init):
181
182 ::respawn:/bin/cttyhack /bin/sh
183
184 Starting an interactive shell from boot shell script:
185
186 setsid cttyhack sh
187
188 Giving controlling tty to shell running with PID 1:
189
190 # exec cttyhack sh
191
192 Without cttyhack, you need to know exact tty name,
193 and do something like this:
194
195 # exec setsid sh -c 'exec sh </dev/tty1 >/dev/tty1 2>&1'
196
197endmenu 161endmenu
diff --git a/shell/Kbuild.src b/shell/Kbuild.src
index bce99240f..a669bdfb0 100644
--- a/shell/Kbuild.src
+++ b/shell/Kbuild.src
@@ -8,5 +8,4 @@ lib-y:=
8 8
9INSERT 9INSERT
10 10
11lib-$(CONFIG_CTTYHACK) += cttyhack.o
12lib-$(CONFIG_SH_MATH_SUPPORT) += math.o 11lib-$(CONFIG_SH_MATH_SUPPORT) += math.o
diff --git a/shell/ash.c b/shell/ash.c
index 9b33e78ec..fd119fa51 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -179,6 +179,7 @@
179//config: "PS#" may contain volatile content, such as backquote commands. 179//config: "PS#" may contain volatile content, such as backquote commands.
180//config: This option recreates the prompt string from the environment 180//config: This option recreates the prompt string from the environment
181//config: variable each time it is displayed. 181//config: variable each time it is displayed.
182//config:
182 183
183//usage:#define ash_trivial_usage NOUSAGE_STR 184//usage:#define ash_trivial_usage NOUSAGE_STR
184//usage:#define ash_full_usage "" 185//usage:#define ash_full_usage ""
diff --git a/shell/cttyhack.c b/shell/cttyhack.c
index 67736ad62..7af13fdfd 100644
--- a/shell/cttyhack.c
+++ b/shell/cttyhack.c
@@ -6,6 +6,58 @@
6 */ 6 */
7#include "libbb.h" 7#include "libbb.h"
8 8
9//applet:IF_CTTYHACK(APPLET(cttyhack, _BB_DIR_BIN, _BB_SUID_DROP))
10
11//kbuild:lib-$(CONFIG_CTTYHACK) += cttyhack.o
12
13//config:config CTTYHACK
14//config: bool "cttyhack"
15//config: default y
16//config: help
17//config: One common problem reported on the mailing list is "can't access tty;
18//config: job control turned off" error message which typically appears when
19//config: one tries to use shell with stdin/stdout opened to /dev/console.
20//config: This device is special - it cannot be a controlling tty.
21//config:
22//config: Proper solution is to use correct device instead of /dev/console.
23//config:
24//config: cttyhack provides "quick and dirty" solution to this problem.
25//config: It analyzes stdin with various ioctls, trying to determine whether
26//config: it is a /dev/ttyN or /dev/ttySN (virtual terminal or serial line).
27//config: If it detects one, it closes stdin/out/err and reopens that device.
28//config: Then it executes given program. Opening the device will make
29//config: that device a controlling tty. This may require cttyhack
30//config: to be a session leader.
31//config:
32//config: Example for /etc/inittab (for busybox init):
33//config:
34//config: ::respawn:/bin/cttyhack /bin/sh
35//config:
36//config: Starting an interactive shell from boot shell script:
37//config:
38//config: setsid cttyhack sh
39//config:
40//config: Giving controlling tty to shell running with PID 1:
41//config:
42//config: # exec cttyhack sh
43//config:
44//config: Without cttyhack, you need to know exact tty name,
45//config: and do something like this:
46//config:
47//config: # exec setsid sh -c 'exec sh </dev/tty1 >/dev/tty1 2>&1'
48//config:
49
50//usage:#define cttyhack_trivial_usage
51//usage: "PROG ARGS"
52//usage:#define cttyhack_full_usage "\n\n"
53//usage: "Give PROG a controlling tty if possible."
54//usage: "\nExample for /etc/inittab (for busybox init):"
55//usage: "\n ::respawn:/bin/cttyhack /bin/sh"
56//usage: "\nGiving controlling tty to shell running with PID 1:"
57//usage: "\n $ exec cttyhack sh"
58//usage: "\nStarting interactive shell from boot shell script:"
59//usage: "\n setsid cttyhack sh"
60
9/* From <linux/vt.h> */ 61/* From <linux/vt.h> */
10struct vt_stat { 62struct vt_stat {
11 unsigned short v_active; /* active vt */ 63 unsigned short v_active; /* active vt */