f8a5b792b
Denys Vlasenko
2011-10-31
Subject
cttyhack: move /sys/class/tty/console/active check to the front
Binary
No binary (build failed)
Architecture & Compiler Flags
—
Build Log
(log yok)
Commit Diff GitHub →
shell/cttyhack.c+18 -13
| @@ -117,7 +117,24 @@ int cttyhack_main(int argc UNUSED_PARAM, char **argv) | |
| /* We don't have ctty (or don't have "/dev/tty" node...) */ | |
| do { | |
| #ifdef __linux__ | |
| - | int s; |
| + | /* Note that this method does not use _stdin_. |
| + | * Thus, "cttyhack </dev/something" can't be used. |
| + | * However, this method is more reliable than |
| + | * TIOCGSERIAL check, which assumes that all |
| + | * serial lines follow /dev/ttySn convention - |
| + | * which is not always the case. |
| + | * Therefore, we use this methos first: |
| + | */ |
| + | int s = open_read_close("/sys/class/tty/console/active", |
| + | console + 5, sizeof(console) - 5); |
| + | if (s > 0) { |
| + | /* found active console via sysfs (Linux 2.6.38+) |
| + | * sysfs string looks like "ttyS0\n" so zap the newline: |
| + | */ |
| + | console[4 + s] = '\0'; |
| + | break; |
| + | } |
| + | |
| if (ioctl(0, VT_GETSTATE, &u.vt) == 0) { | |
| /* this is linux virtual tty */ | |
| sprintf(console + 8, "S%u" + 1, (int)u.vt.v_active); | |
| @@ -130,18 +147,6 @@ int cttyhack_main(int argc UNUSED_PARAM, char **argv) | |
| sprintf(console + 8, "S%u", (int)u.sr.line); | |
| break; | |
| } | |
| - | #endif |
| - | #ifdef __linux__ |
| - | /* Note that this method is not related to _stdin_ */ |
| - | s = open_read_close("/sys/class/tty/console/active", |
| - | console + 5, sizeof(console) - 5); |
| - | if (s > 0) { |
| - | /* found active console via sysfs (Linux 2.6.38+) |
| - | * sysfs string looks like "ttyS0\n" so zap the newline: |
| - | */ |
| - | console[4 + s] = '\0'; |
| - | break; |
| - | } |
| #endif | |
| /* nope, could not find it */ | |
| console[0] = '\0'; | |