dish/exec.c

/*
 * @Author: 1ridic
 * @Date: 2022-09-18 14:14:23
 * @Last Modified by: 1ridic
 * @Last Modified time: 2022-09-18 23:31:39
 */
#include "builtin.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>

extern int (*builtin_func[])(char **);
extern char *builtin_cmd[];

int forkExec(char **args) {
  pid_t pid;
#ifdef DEBUG
  printf("debug: fork enter.\n");
#endif
  pid = fork();
  if (pid == 0) {
    /* child process */
    if (execvp(args[0], args) == -1) {
      perror("dish");
      exit(EXIT_FAILURE);
    }
  } else if (pid < 0) {
    /* fork error */
    perror("dish");
  } else {
    extern char volatile isWaiting;
    isWaiting = 1;
    /* parent process: wait child process*/
    int stat_val;
    waitpid(pid, &stat_val, 0);
    if (WIFEXITED(stat_val)) {
      isWaiting = 0;
      return WEXITSTATUS(stat_val);
    }
    else if (WIFSIGNALED(stat_val)) {
      isWaiting = 1;
      return WTERMSIG(stat_val);
    }
  }
  return -100;
}

int commandExec(char **args) {
  int i;

  if (args[0] == NULL) {
    /* empty command */
    return 1;
  }

  for (i = 0; i < getBuiltinNum(); i++) {
    if (strcmp(args[0], builtin_cmd[i]) == 0) {
      return (*builtin_func[i])(args);
    }
  }

  return forkExec(args);
}