[BusyBox] New applet: openvt

[Quy Tonthat]

Hi,
Just a simple implementation of open that starts a vt on the console.
I often use it for init to start up shell's on console. Hope it can be
any use
for someone else.
Quy

-------------- next part --------------
--- ./usage.h- Sat Apr 27 11:31:31 2002
+++ ./usage.h Fri Aug 9 02:22:43 2002
@@ -1860,3 +1860,10 @@
"FILE"
#define zcat_full_usage \
"Uncompress to stdout."
+
+#define openvt_trivial_usage \
+ "<vtnum> <COMMAND> [ARGS...]"
+#define openvt_full_usage \
+ "Start a command on a new virtual terminal"
+#define openvt_example_usage \
+ "openvt 2 /bin/ash\n"
--- ./Config.h- Sat Apr 6 14:22:15 2002
+++ ./Config.h Fri Aug 9 01:04:51 2002
@@ -87,6 +87,7 @@
#define BB_MV
//#define BB_NC
//#define BB_NSLOOKUP
+#define BB_OPENVT
#define BB_PIDOF
//#define BB_PING
//#define BB_PIVOT_ROOT
--- ./openvt.c- Tue Sep 3 17:18:13 2002
+++ ./openvt.c Sat Sep 7 00:02:52 2002
@@ -0,0 +1,76 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * openvt.c - open a vt to run a command.
+ *
+ * busyboxed by Quy Tonthat <***@signal3.com>
+ */
+
+/* getopt not needed */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <string.h>
+#include <sys/types.h>
+#include "busybox.h"
+
+#define VTNAME "/dev/tty%d"
+
+int openvt_main(int argc, char **argv)
+{
+ int pid;
+ int fd;
+ int vtno;
+ char vtname[sizeof VTNAME + 2];
+ char * cmd = NULL;
+ char * cmd_args = NULL;
+
+ if (argc < 3)
+ show_usage();
+ if (!isdigit(argv[1][0]))
+ show_usage();
+
+ vtno = (int) atol(argv[1]);
+ /* if (vtno <= 0 || vtno > 63) */
+ if (vtno <= 0 || vtno > 12)
+ error_msg_and_die("Illegal vt number (%d)", vtno);
+ sprintf(vtname, VTNAME, vtno);
+
+ cmd = argv[2];
+ cmd_args = xmalloc(80);
+ cmd_args[0] = '\0';
+
+ if((pid = fork()) == 0) {
+ /* leave current vt */
+#ifdef ESIX_5_3_2_D
+ if (setpgrp() < 0) {
+#else
+ if (setsid() < 0) {
+#endif
+ perror_msg_and_die("Unable to set new session");
+ }
+ close(0); /* so that new vt becomes stdin */
+
+ /* and grab new one */
+ if ((fd = open(vtname, O_RDWR)) == -1)
+ perror_msg_and_die("could not open %s", vtname);
+ close(1);
+ close(2);
+ dup(fd);
+ dup(fd);
+ execvp(cmd, &argv[2]);
+ /*execlp(cmd, cmd_args);*/
+ _exit(1);
+ }
+ return EXIT_SUCCESS;
+}
+
+
+/*
+Local Variables:
+c-file-style: "linux"
+c-basic-offset: 4
+tab-width: 4
+End:
+*/
--- ./applets.h- Wed Mar 20 13:10:21 2002
+++ ./applets.h Fri Aug 9 01:03:19 2002
@@ -299,6 +299,9 @@
#ifdef BB_NSLOOKUP
APPLET(nslookup, nslookup_main, _BB_DIR_USR_BIN)
#endif
+#ifdef BB_OPENVT
+ APPLET(openvt, openvt_main, _BB_DIR_USR_BIN)
+#endif
#ifdef BB_PIDOF
APPLET(pidof, pidof_main, _BB_DIR_BIN)
#endif

[Glenn McGrath]

On Sat, 07 Sep 2002 00:27:20 +1000

Post by Quy Tonthat
Hi,
Just a simple implementation of open that starts a vt on the console.
I often use it for init to start up shell's on console. Hope it can be
any use
for someone else.
Quy

Im wondering, what is the purpose of the two dup(fd); statements in this
instance ?

+ /* and grab new one */
+ if ((fd = open(vtname, O_RDWR)) == -1)
+ perror_msg_and_die("could not open %s", vtname);
+ close(1);
+ close(2);
+ dup(fd);
+ dup(fd);
+ execvp(cmd, &argv[2]);
+ /*execlp(cmd, cmd_args);*/
+ _exit(1);
+ }
+ return EXIT_SUCCESS;
+}



Glenn

[Quy Tonthat]

Post by Glenn McGrath
On Sat, 07 Sep 2002 00:27:20 +1000

Post by Quy Tonthat
Hi,
Just a simple implementation of open that starts a vt on the console.
I often use it for init to start up shell's on console. Hope it can be
any use
for someone else.
Quy

Im wondering, what is the purpose of the two dup(fd); statements in this
instance ?
+ /* and grab new one */
+ if ((fd = open(vtname, O_RDWR)) == -1)
+ perror_msg_and_die("could not open %s", vtname);
+ close(1);
+ close(2);
+ dup(fd);
+ dup(fd);
+ execvp(cmd, &argv[2]);
+ /*execlp(cmd, cmd_args);*/
+ _exit(1);
+ }
+ return EXIT_SUCCESS;
+}
Glenn

Just to make sure stdout and stderr of the child will go to the vt.
Quy

[Quy Tonthat]

Post by Glenn McGrath
On Sat, 07 Sep 2002 00:27:20 +1000

Post by Quy Tonthat
Hi,
Just a simple implementation of open that starts a vt on the console.
I often use it for init to start up shell's on console. Hope it can be
any use
for someone else.
Quy

Im wondering, what is the purpose of the two dup(fd); statements in this
instance ?
+ /* and grab new one */
+ if ((fd = open(vtname, O_RDWR)) == -1)
+ perror_msg_and_die("could not open %s", vtname);
+ close(1);
+ close(2);
+ dup(fd);
+ dup(fd);
+ execvp(cmd, &argv[2]);
+ /*execlp(cmd, cmd_args);*/
+ _exit(1);
+ }
+ return EXIT_SUCCESS;
+}
Glenn

Just to make sure stdout and stderr of the child will go to the vt.
Quy

[Glenn McGrath]

On Sat, 07 Sep 2002 00:27:20 +1000

Post by Quy Tonthat
Hi,
Just a simple implementation of open that starts a vt on the console.
I often use it for init to start up shell's on console. Hope it can be
any use
for someone else.
Quy

I commited it to unstable, i should have checked beforehand but it doesnt
mention the license at the top of openvt.c, is it safe to assume its GPL
v2 or later ?



Glenn

[Quy Tonthat]

Post by Glenn McGrath
On Sat, 07 Sep 2002 00:27:20 +1000

Post by Quy Tonthat
Hi,
Just a simple implementation of open that starts a vt on the console.
I often use it for init to start up shell's on console. Hope it can be
any use
for someone else.
Quy

I commited it to unstable, i should have checked beforehand but it doesnt
mention the license at the top of openvt.c, is it safe to assume its GPL
v2 or later ?
Glenn

Yes, it's GPL V2.
Sorry for missing the license header. Feel free to add it in if you like.

Quy

[Quy Tonthat]

Post by Glenn McGrath
On Sat, 07 Sep 2002 00:27:20 +1000

Post by Quy Tonthat
Hi,
Just a simple implementation of open that starts a vt on the console.
I often use it for init to start up shell's on console. Hope it can be
any use
for someone else.
Quy

I commited it to unstable, i should have checked beforehand but it doesnt
mention the license at the top of openvt.c, is it safe to assume its GPL
v2 or later ?
Glenn

Yes, it's GPL V2.
Sorry for missing the license header. Feel free to add it in if you like.

Quy

[Quy Tonthat]

Hi,
Just a simple implementation of open that starts a vt on the console.
I often use it for init to start up shell's on console. Hope it can be
any use
for someone else.
Quy

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[Glenn McGrath]

On Sat, 07 Sep 2002 00:27:20 +1000

Post by Quy Tonthat
Hi,
Just a simple implementation of open that starts a vt on the console.
I often use it for init to start up shell's on console. Hope it can be
any use
for someone else.
Quy

Im wondering, what is the purpose of the two dup(fd); statements in this
instance ?

+ /* and grab new one */
+ if ((fd = open(vtname, O_RDWR)) == -1)
+ perror_msg_and_die("could not open %s", vtname);
+ close(1);
+ close(2);
+ dup(fd);
+ dup(fd);
+ execvp(cmd, &argv[2]);
+ /*execlp(cmd, cmd_args);*/
+ _exit(1);
+ }
+ return EXIT_SUCCESS;
+}



Glenn

[Glenn McGrath]

On Sat, 07 Sep 2002 00:27:20 +1000

Post by Quy Tonthat
Hi,
Just a simple implementation of open that starts a vt on the console.
I often use it for init to start up shell's on console. Hope it can be
any use
for someone else.
Quy

I commited it to unstable, i should have checked beforehand but it doesnt
mention the license at the top of openvt.c, is it safe to assume its GPL
v2 or later ?



Glenn