changeset 1214:a31d747b0017

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.
author Vivek Bhagat <vivek.bhagat89@gmail.com>
date Sun, 09 Mar 2014 14:27:11 -0500
parents 5918424045a1
children 4eaac3e63fa7
files toys/pending/deallocvt.c toys/pending/freeramdisk.c toys/pending/openvt.c
diffstat 3 files changed, 198 insertions(+), 0 deletions(-) [+]
line wrap: on
line diff
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toys/pending/deallocvt.c	Sun Mar 09 14:27:11 2014 -0500
@@ -0,0 +1,37 @@
+/* deallocvt.c - Deallocate virtual terminal(s)
+ *
+ * Copyright 2014 Vivek Kumar Bhagat <vivek.bhagat89@gmail.com>
+ *
+ * No Standard.
+
+USE_DEALLOCVT(NEWTOY(deallocvt, ">1", TOYFLAG_USR|TOYFLAG_BIN|TOYFLAG_NEEDROOT))
+
+config DEALLOCVT
+  bool "deallocvt"
+	depends on OPENVT
+  default n
+  help
+		usage: deallocvt [N]
+
+		Deallocate unused virtual terminal /dev/ttyN
+		default value of N is 0, deallocate all unused consoles
+*/
+
+#include "toys.h"
+#include <linux/vt.h>
+
+void deallocvt_main(void)
+{
+	int fd;
+
+	// 0 : deallocate all unused consoles
+	int vt_num = 0;
+
+	if (toys.optargs[0])
+		vt_num = atolx_range(toys.optargs[0], 1, 63);
+
+	fd = find_console_fd();
+	if (fd < 0)	error_exit("can't open console");
+
+	xioctl(fd, VT_DISALLOCATE, (void *)(ptrdiff_t)vt_num);
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toys/pending/freeramdisk.c	Sun Mar 09 14:27:11 2014 -0500
@@ -0,0 +1,27 @@
+/* freeramdisk.c - Free all memory allocated to ramdisk
+ *
+ * Copyright 2014 Vivek Kumar Bhagat <vivek.bhagat89@gmail.com>
+ *
+ * No Standard
+
+USE_FREERAMDISK(NEWTOY(freeramdisk, "<1>1", TOYFLAG_SBIN|TOYFLAG_NEEDROOT))
+
+config FREERAMDISK
+  bool "freeramdisk"
+  default n
+  help
+    usage: freeramdisk <RAM device>
+
+    Free all memory allocated to specified ramdisk
+*/
+
+#include "toys.h"
+
+void freeramdisk_main(void)
+{
+	int fd;
+
+	fd = xopen(toys.optargs[0], O_RDWR);
+	xioctl(fd, BLKFLSBUF, toys.optargs[0]);
+	xclose(fd);
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toys/pending/openvt.c	Sun Mar 09 14:27:11 2014 -0500
@@ -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); 
+		}
+	}
+}