10 Years
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Last Post by lcfoo

If I want to exit to Dos in a C program from a Switch statement, how do I do it?


So no moderators on assembly forum? This should be moved to c/c++ forum. Ok I will tell you. Suposing that your switch statemant is in main function.

int main()
   /* declare someNum */
   /* assigning value to someNum */
   case something1:
      /* do stuff */
   case something2:
      /* do stuff */
      return 1; /* exiting from program */
      break; /* damn never be here */
   /* here doing something what you tought to do */
   return 0;

If you creat project, creat console app. Hope I understood your problem.


Use system command in C language.
Another way is using piping handlers in C language.

       system - execute a shell command
       #include <stdlib.h>
       int system (const char * string);
       system()  executes  a  command specified in string by calling /bin/sh -c string, and returns after the command has been completed.  During execution of the com-
       mand, SIGCHLD will be blocked, and SIGINT and SIGQUIT will be ignored.
       The value returned is 127 if the execve() call for /bin/sh fails, -1 if there was another error and the return code of the command otherwise.
       If the value of string is NULL, system() returns nonzero if the shell is available, and zero if not.
       system() does not affect the wait status of any other children.
       It is extremely unfortunate that the libc version of system() ignores interrupts.  This makes programs that call it from a  loop  uninterruptable.   This  means
       that for such purposes one should not use system() but a private version like (warning: untested code!)
       int my_system (const char *command) {
           int pid, status;
           if (command == 0)
               return 1;
           pid = fork();
           if (pid == -1)
               return -1;
           if (pid == 0) {
               char *argv[4];
               argv[0] = "sh";
               argv[1] = "-c";
               argv[2] = command;
               argv[3] = 0;
               execve("/bin/sh", argv, environ);
           do {
               if (waitpid(pid, &status, 0) == -1) {
                   if (errno != EINTR)
                       return -1;
           do {
               if (waitpid(pid, &status, 0) == -1) {
                   if (errno != EINTR)
                       return -1;
               } else
                   return status;
           } while(1);
       Do  not  use  system()  from  a  program  with  suid  or  sgid privileges, because strange values for some environment variables might be used to subvert system
       integrity.  Use the exec(3) family of functions instead, but not execlp(3) or execvp(3).  system() will not, in fact, work properly from programs with  suid  or
       sgid  privileges  on  systems on which /bin/sh is bash version 2, since bash 2 drops privileges on startup.  (Debian uses a modified bash which does not do this
       when invoked as sh.)
       The check for the availability of /bin/sh is not actually performed; it is always assumed to be available.  ISO C specifies the  check,  but  POSIX.2  specifies
       that the return shall always be non-zero, since a system without the shell is not conforming, and it is this that is implemented.
       It is possible for the shell command to return 127, so that code is not a sure indication that the execve() call failed; check errno to make sure.

Edited by pyTony: fixed formatting

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