[SOLVED] redirecting output of execvp into a file in C

redirecting output of execvp into a file in C

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");
}

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

Solution

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

Try this:

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

/* If this is reached execvp failed. */

perror("execvp");

Alternatively you can use compound literals:

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

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