#include <limits.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/wait.h>
#define PROMPT_STRING "ush2>>"
#define QUIT_STRING "q"

void executecmd(char *incmd);

int main (void) {
   pid_t childpid;
   char inbuf[MAX_CANON];
   int len;

   for( ; ; ) {
      if (fputs(PROMPT_STRING, stdout) == EOF)
          continue;
      if (fgets(inbuf, MAX_CANON, stdin) == NULL)
          continue; 
      len = strlen(inbuf);
      if (inbuf[len - 1] == '\n')
          inbuf[len - 1] = 0;
      if (strcmp(inbuf, QUIT_STRING) == 0)
          break;
      if ((childpid = fork()) == -1)
          perror("Failed to fork child");
      else if (childpid == 0) {
          executecmd(inbuf);
          return 1; 
      } else 
         wait(NULL);
   }
   return 0; 
}