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为什么改变C区Stdin方向不起作用?
原标题:Why does redirecting stdin in C not work?

我试图通过管道“我的管道” 将标准从父母转到孩子身上, 但是当我运行我的程序时, 我看不到预期的结果。

当我执行程序时, 它会期待从标准输入, 那么为什么它不将标准转换到 dup2 中?

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <unistd.h>
#include <string.h>



int main(int argc, char* argv[])
{
    char* arguments[] = {"sort", NULL};

    int my_pipe[2];
    if(pipe(my_pipe) == -1)
    {
        fprintf(stderr, "Error creating pipe
");
    }

    pid_t child_id;
    child_id = fork();
    if(child_id == -1)
    {
        fprintf(stderr, "Fork error
");
    }
    if(child_id == 0) // child process
    {
        close(my_pipe[1]); // child doesn t write
        dup2(0, my_pipe[0]); // redirect stdin

        execvp(argv[0], arguments);

        fprintf(stderr, "Exec failed
");
    }
    else
    {
        close(my_pipe[0]); // parent doesn t read

        char reading_buf[1];
        write(my_pipe[1], "hello", strlen("hello"));
        write(my_pipe[1], "friend", strlen("friend"));
        close(my_pipe[1]);
        wait();
    }
}
最佳回答

您对 dup2 的参数向后退 。 请尝试 < code> dup2( my_ ippub [0], STDIN_ FILENO)

问题回答

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