使用execvp（）执行shell命令(Executing shell commands with execvp())

 我想编写一个类似于Linux shell的程序。 我开始编写一个小程序来执行“ls”命令。 我无法弄清楚的是我应该如何进行以使我的程序响应像shell这样的任何命令。 （例如cat，cd，dir）。 
 
#include <iostream>
#include <unistd.h>
#include <sys/types.h>
#include <stdlib.h>
#define MAX 32
using namespace std;

int main() {
    pid_t c; 
    char s[MAX];
    int fd[2];
    int n;

    pipe(fd);
    c = fork();

    if(c == 0) {
        close(fd[0]);
        dup2(fd[1], 1);
        execlp("ls", "ls", "-l", NULL);
        return 0;
    } else {
        close(fd[1]);
        while( (n = read(fd[0], s, MAX-1)) > 0 ) {
            s[n] = '\0';
            cout<<s;
        }
        close(fd[0]);
        return 0;
    }

    return 0;
}
 
 如何让我的程序读取用户键入的内容并将其传递给execlp （或类似的东西）？ 

I want to write a program which acts like a Linux shell. I started with writing a small program to execute the "ls" command. What I can't figure out is how should I proceed in order to make my program respond to any command like the shell does. ( e.g cat, cd, dir).
 
#include <iostream>
#include <unistd.h>
#include <sys/types.h>
#include <stdlib.h>
#define MAX 32
using namespace std;

int main() {
    pid_t c; 
    char s[MAX];
    int fd[2];
    int n;

    pipe(fd);
    c = fork();

    if(c == 0) {
        close(fd[0]);
        dup2(fd[1], 1);
        execlp("ls", "ls", "-l", NULL);
        return 0;
    } else {
        close(fd[1]);
        while( (n = read(fd[0], s, MAX-1)) > 0 ) {
            s[n] = '\0';
            cout<<s;
        }
        close(fd[0]);
        return 0;
    }

    return 0;
}
 
How can I make my program read what the user types in and passes it to execlp (or something similar that does the same thing)?

原文：https://stackoverflow.com/questions/27491669