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/* Newvc - run a program in another virtual console */
/* Copyright (C) 1992 by MAEDA Atusi (mad@math.keio.ac.jp) */
/* Version 0.1 92/1/11 */
/* Version 0.2 92/1/19 */
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <unistd.h>
#include <limits.h>
#include <pwd.h>
#include <utmp.h>
#include <time.h>
#include <sys/file.h>
#include <sys/ioctl.h>
#include <sys/kd.h>
#include <sys/vt.h>
#include <sys/wait.h>
#define MAXTTYLEN 12
#define MAXCMDLEN 4096
char cmdBuf[MAXCMDLEN];
char *progName;
char newTtyName[MAXTTYLEN];
void error(const char *message, const char *perrorMessage) {
fprintf(stderr, "%s: %s\n", progName, message);
if (perrorMessage) {
perror(perrorMessage);
}
exit(EXIT_FAILURE);
}
struct passwd *pw;
struct utmp ut;
void setUtmpEntry(int pid) {
pw = getpwuid(getuid());
setutent(); /* open utmp */
strncpy(ut.ut_id, newTtyName + strlen("/dev/tty"), sizeof(ut.ut_id));
ut.ut_type = DEAD_PROCESS;
getutid(&ut); /* set position */
/* Set up the new entry. */
ut.ut_type = USER_PROCESS;
strncpy(ut.ut_line, newTtyName + strlen("/dev/"), sizeof(ut.ut_line));
strncpy(ut.ut_user, (pw && pw->pw_name) ? pw->pw_name : "????",
sizeof(ut.ut_user));
/*
gethostname(ut.ut_host, sizeof(ut.ut_host));
*/
ut.ut_pid = pid;
ut.ut_time = time(NULL);
pututline(&ut);
endutent(); /* close utmp */
}
void restoreUtmpEntry(int pid) {
struct utmp *utp;
pw = getpwuid(getuid());
setutent(); /* open utmp */
strncpy(ut.ut_id, newTtyName + strlen("/dev/tty"), sizeof(ut.ut_id));
ut.ut_type = USER_PROCESS;
utp = getutid(&ut); /* search entry */
/* Set up the new entry. */
if (utp && utp->ut_pid == pid) {
ut.ut_type = DEAD_PROCESS;
ut.ut_time = time(NULL);
pututline(&ut);
}
endutent(); /* close utmp */
}
int main(int argc, char* argv[]) {
int curVcNum, newVcNum;
int consoleFd = 0;
int newVcFd;
int childPid;
struct vt_stat vts;
progName = argv[0];
if ((consoleFd = open("/dev/console", 0)) < 0) {
error("can't open console", "/dev/console");
}
ioctl(consoleFd, VT_GETSTATE, &vts);
curVcNum = vts.v_active;
ioctl(consoleFd, VT_OPENQRY, &newVcNum);
if (newVcNum < 0) {
error("can't find unused virtual console", NULL);
}
sprintf(newTtyName, "/dev/tty%d", newVcNum);
setsid();
if ((newVcFd = open(newTtyName, O_RDWR)) < 0) {
error("can't open virtual console", newTtyName);
}
if (ioctl(consoleFd, VT_ACTIVATE, newVcNum) != 0) {
error("can't switch virtual console", "ioctl VT_ACTIVATE");
}
dup2(newVcFd, 0);
dup2(newVcFd, 1);
dup2(newVcFd, 2);
if ((childPid = fork()) < 0) {
error("fork failed", "fork");
}
if (childPid) {
/* Parent process. */
int status;
setUtmpEntry(childPid);
wait(&status);
restoreUtmpEntry(childPid);
if (ioctl(0, VT_ACTIVATE, curVcNum) != 0) {
error("couldn't restore original console", "ioctl(0, VT_ACTIVATE)");
}
return WEXITSTATUS(status);
} else {
/* Child process. */
char *shell, *command;
char *newArgv[] = {"/bin/sh", "-c", cmdBuf, NULL};
setuid(getuid());
setgid(getgid());
if ((shell = getenv("SHELL")) == NULL) {
shell = "/bin/sh";
}
if (argc == 1) {
/* No command specified. Run shell as default. */
if ((command = rindex(shell, '/')) == NULL) {
command = shell;
} else {
command++;
}
newArgv[1] = NULL;
} else {
int i;
command = argv[1];
for (i = 1; i < argc; i++) {
strncat(cmdBuf, argv[i], MAXCMDLEN);
strncat(cmdBuf, " ", MAXCMDLEN);
}
}
newArgv[0] = command;
execv(shell, newArgv);
error("can't exec", shell);
return EXIT_FAILURE;
}
}
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