c - 在C中更改子进程中的当前工作目录

Question

我必须编写一个程序来生成子进程而不是结束父进程，然后创建的子进程必须要求用户输入新的工作目录，更改它并打印到其新工作目录的路径。我写了这个，但是 scanf 不起作用（“它没有要求用户输入内容，程序刚刚结束）并且路径没有改变......我试图将新目录设置为char *newdirectory="home/usr/desktop"并且也没有改变工作目录

#include <unistd.h>
#include <stdio.h>
#include <errno.h>
#include <stdlib.h>
#include <sys/stat.h>

int main()
{
    int pid;
    char directory[1024];
    char newdirectory[1024];        
    pid=fork(); 
    if(pid<0)
    {
        printf("\n Error ");
        exit(1);
    }
    else if(pid==0)
    {
        printf("I'm child \n ");
        printf(" My PID: %d \n",getpid());
        getcwd(directory, sizeof(directory));
        printf(" My current working directory is: %s\n", directory);
        printf(" Enter the new path\n");
        scanf("%s", &newdirectory);
        chdir(newdirectory);
        getcwd(directory, sizeof(directory));
        printf(" Path changed to: %s\n", directory);
        exit(0);
    }
    else
    {
        printf("I'm a parent \n ");
        printf("My PID is %d \n ",getpid());
        printf("Bye bye \n");
        exit(1);
    }
    return 0;
}

感谢您的时间、精力和所有帮助理解 :)

Answer 1

你有两个错误，

• 的使用scanf()
• 不等待孩子完成其作为父母的任务。

以下作品。

#include <unistd.h>
#include <stdio.h>
#include <errno.h>
#include <stdlib.h>
#include <sys/stat.h>

int main()
{
    int pid;
    char directory[1024];
    char newdirectory[1024];
    pid=fork();
    if(pid<0)
    {
        printf("\n Error ");
        exit(1);
    }
    else if(pid==0)
    {
        printf("I'm child \n ");
        printf(" My PID: %d \n",getpid());
        getcwd(directory, sizeof(directory));
        printf(" My current working directory is: %s\n", directory);
        printf(" Enter the new path\n");
        scanf("%1023s", newdirectory);
        chdir(newdirectory);
        getcwd(directory, sizeof(directory));
        printf(" Path changed to: %s\n", directory);
        exit(0);
    }
    else
    {
        wait(0);
        printf("I'm a parent \n ");
        printf("My PID is %d \n ",getpid());
        printf("Bye bye \n");
        exit(1);
    }
}