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author | Vivek Bhagat <vivek.bhagat89@gmail.com> | 2014-03-09 14:27:11 -0500 |
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committer | Vivek Bhagat <vivek.bhagat89@gmail.com> | 2014-03-09 14:27:11 -0500 |
commit | 728b8ff0a01f5adb01c5a44886cba644f8415837 (patch) | |
tree | 847d42d91c3e01b89efba8afcee6b744a110b6e9 /toys/pending/openvt.c | |
parent | 4d886d69511e3d3a7b3c3ead914f638b01ff7433 (diff) | |
download | toybox-728b8ff0a01f5adb01c5a44886cba644f8415837.tar.gz |
Please find the patches attached herewith for adding 3 new commands -
1. freeramdisk - If we unmount or detach the RAM disk based file system the Linux Kernel
will not free the allocated memory associated with the RAM device. This can be useful if
one wants to mount this device again: All data will be preserved.
If we need to free the memory back to the Kernel, one can use the command: "toybox freeramdisk <RAM device>".
2. openvt - Successfully opens a new virtual terminal as mentioned with -c option
otherwise search and open next available VT.
with -s option it switches to new VT
with -s -w option, it switch back successfully to originating VT.
3. deallocvt - Deallocate specified virtual teminal.
if no virtual terminal is specified, it deallocates all unused VT.
Diffstat (limited to 'toys/pending/openvt.c')
-rw-r--r-- | toys/pending/openvt.c | 134 |
1 files changed, 134 insertions, 0 deletions
diff --git a/toys/pending/openvt.c b/toys/pending/openvt.c new file mode 100644 index 00000000..5aecd945 --- /dev/null +++ b/toys/pending/openvt.c @@ -0,0 +1,134 @@ +/* openvt.c - Run a program on a new VT + * + * Copyright 2014 Vivek Kumar Bhagat <vivek.bhagat89@gmail.com> + * + * No Standard + +USE_OPENVT(NEWTOY(openvt, "c#<1>63sw", TOYFLAG_BIN|TOYFLAG_NEEDROOT)) + +config OPENVT + bool "openvt" + default n + help + usage: openvt [-c N] [-s] [-w] [--] [command [command_options]] + + start a program on a new virtual terminal (VT) + + -c N Use VT N + -s Switch to new VT + -w Wait for command to exit + if -s and -w option used together, switch back + to originating VT when command completes +*/ + +#define FOR_openvt +#include "toys.h" +#include <linux/vt.h> +#include <linux/kd.h> + +GLOBALS( + unsigned long vt_num; +) + +int find_console_fd(void) +{ + char *console_name[] = {"/dev/tty", "/dev/tty0", "/dev/console"}; + int i; + int fd; + char arg; + + for (i = 0; i < 3; i++) { + fd = open(console_name[i], O_RDWR); + if (fd < 0 && errno == EACCES) + fd = open(console_name[i], O_RDONLY); + + if (fd < 0 && errno == EACCES) + fd = open(console_name[i], O_WRONLY); + + if (fd >= 0) { + arg = 0; + if (0 == ioctl(fd, KDGKBTYPE, &arg)) + return fd; + else + close(fd); + } + } + + /* check std fd 0, 1 and 2 */ + for (fd = 0; fd < 3; fd++) { + arg = 0; + if (0 == ioctl(fd, KDGKBTYPE, &arg)) + return fd; + } + + return -1; +} + +int xvtnum(int fd) +{ + int ret; + + ret = ioctl(fd, VT_OPENQRY, (int *)&TT.vt_num); + if (ret != 0 || TT.vt_num <= 0) perror_exit("can't find open VT"); + + return TT.vt_num; +} + +void openvt_main(void) +{ + int fd = -1, vt_fd = -1, pid, ret = 0; + struct vt_stat vstate; + + if (!(toys.optflags & FLAG_c)) { + // check if fd 0,1 or 2 is already opened + for (fd = 0; fd < 3; fd++) + if (!ioctl(fd, VT_GETSTATE, &vstate)) { + ret = xvtnum(fd); + break; + } + + // find VT number using /dev/console + if (!ret) { + fd = xopen("/dev/console", O_RDONLY | O_NONBLOCK); + xioctl(fd, VT_GETSTATE, &vstate); + xvtnum(fd); + } + } + + sprintf(toybuf, "/dev/tty%lu", TT.vt_num); + fd = find_console_fd(); + xioctl(fd, VT_GETSTATE, &vstate); + + close(0); //new vt becomes stdin + vt_fd = xopen(toybuf, O_RDWR); + if (toys.optflags & FLAG_s) { + ioctl(vt_fd, VT_ACTIVATE, TT.vt_num); + ioctl(vt_fd, VT_WAITACTIVE, TT.vt_num); + } + + close(1); + close(2); + dup2(vt_fd, 1); + dup2(vt_fd, 2); + while (vt_fd > 2) + close(vt_fd--); + + pid = vfork(); + if (pid < 0) perror_exit("Fork failed"); + else if (!pid) { + setsid(); + ioctl(vt_fd, TIOCSCTTY, 0); + xexec(toys.optargs); + } + + if (toys.optflags & FLAG_w) { + while (-1 == waitpid(pid, NULL, 0) && errno == EINTR) + ; + if (toys.optflags & FLAG_s) { + ioctl(fd, VT_ACTIVATE, vstate.v_active); + ioctl(fd, VT_WAITACTIVE, vstate.v_active); + //check why deallocate isn't working here + xioctl(fd, VT_DISALLOCATE, (void *)(ptrdiff_t)TT.vt_num); + } + } +} |