diff options
author | Eric Andersen <andersen@codepoet.org> | 1999-10-26 03:32:44 +0400 |
---|---|---|
committer | Eric Andersen <andersen@codepoet.org> | 1999-10-26 03:32:44 +0400 |
commit | 0460ff2e5d443b485c2f6447c8c2ece1b3bec9c3 (patch) | |
tree | d761a790ee864a0a566d29c9d56173763fa04888 /utility.c | |
parent | d143e8f2bd03470e891a5e3ccca5734edd917e73 (diff) |
Stuf
Diffstat (limited to 'utility.c')
-rw-r--r-- | utility.c | 92 |
1 files changed, 92 insertions, 0 deletions
@@ -720,5 +720,97 @@ extern int find_match(char *haystack, char *needle, int ignoreCase) } #endif + + +#if (defined BB_CHVT) || (defined BB_DEALLOCVT) + + +#include <linux/kd.h> +#include <sys/ioctl.h> + +int is_a_console(int fd) +{ + char arg; + + arg = 0; + return (ioctl(fd, KDGKBTYPE, &arg) == 0 + && ((arg == KB_101) || (arg == KB_84))); +} + +static int open_a_console(char *fnam) +{ + int fd; + + /* try read-only */ + fd = open(fnam, O_RDWR); + + /* if failed, try read-only */ + if (fd < 0 && errno == EACCES) + fd = open(fnam, O_RDONLY); + + /* if failed, try write-only */ + if (fd < 0 && errno == EACCES) + fd = open(fnam, O_WRONLY); + + /* if failed, fail */ + if (fd < 0) + return -1; + + /* if not a console, fail */ + if (! is_a_console(fd)) + { + close(fd); + return -1; + } + + /* success */ + return fd; +} + +/* + * Get an fd for use with kbd/console ioctls. + * We try several things because opening /dev/console will fail + * if someone else used X (which does a chown on /dev/console). + * + * if tty_name is non-NULL, try this one instead. + */ + +int get_console_fd(char* tty_name) +{ + int fd; + + if (tty_name) + { + if (-1 == (fd = open_a_console(tty_name))) + return -1; + else + return fd; + } + + fd = open_a_console("/dev/tty"); + if (fd >= 0) + return fd; + + fd = open_a_console("/dev/tty0"); + if (fd >= 0) + return fd; + + fd = open_a_console("/dev/console"); + if (fd >= 0) + return fd; + + for (fd = 0; fd < 3; fd++) + if (is_a_console(fd)) + return fd; + + fprintf(stderr, + "Couldnt get a file descriptor referring to the console\n"); + return -1; /* total failure */ +} + + +#endif + + /* END CODE */ |