重定向execvp的输出转换成在C文件 [英] redirecting output of execvp into a file in C

问题描述

我不知道我做错了......但这里是正在执行的code的片段：

I don't know what I am doing wrong... but here is the snippet of code that is being executed:

if (fork() == 0)
    {       
             // child
        int fd = open(fileName, O_RDWR | O_CREAT, S_IRUSR | S_IWUSR);

        dup2(fd, 1);   // make stdout go to file

        execvp("ls","ls");
        close(fd);
            exit(0);
    }
if(wait(&status) == -1)
    {
        printf("ERROR REDIRECT\n");
    }

文件名获取创建，但没有什么inside.What我做错了？

fileName gets created but there is nothing inside.What am I doing wrong?

推荐答案

我的猜测是，execvp不工作，但因为你没有处理程序错误，你看不到它。

My guess is that the execvp doesn't work but since you don't handler errors you don't see it.

试试这个：

char *const args[] = {"ls", NULL};
execvp(args[0], args);

/* If this is reached execvp failed. */

perror("execvp");

另外，您可以使用复合文字：

Alternatively you can use compound literals:

execvp("ls", (char *[]){"ls", NULL});

设想二：尽量正常运行的东西，没有重定向，看看它是如何工作的。

Second idea: try to run things normally, without redirect and see how it works.

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