c - 如何定义系统()

Question

所以我要定义system()函数!这是我的功能:

#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>

void mySystem (char *command)
{    
    execlp (command, command, (char*) 0);
}

int main (int argc, char* argv[])
{    
    for (int i = 1; i < argc; i++) 
    {
        char command[50];
        strcpy(command, argv[i]);
        mySystem(command);
    }

    return 0;
}

然后我试了一下，结果是这样的:

gcc exe6.c;
./a.out ls ls

在这种情况下，它只执行一次 ls。

./a.out "ls -l"

在这种情况下不做任何事情。我做错了什么？

Answer 1

man page实际上告诉你怎么做:

The system() library function uses fork(2) to create a child process that executes the shell command specified in command using execl(3) as follows:

execl("/bin/sh", "sh", "-c", command, (char *) 0);

system() returns after the command has been completed.