Use grep on stdin

Question

So, I have used fork() where the parent is opening a file and reading its contents into a buffer and sending the buffer from the write-end (fd[1]) to the read end (fd[0])

The child process is responsible for reading in the buffer. I want to redirect whatever is in fd[0] to stdin, so I can use Unix commands on it. To give an example:

// in child process
dup2(fd[0], 0); // 0 is STDIN 

// Don't know what to do here

execl("/bin/grep/", "grep", "hello", NULL); // find the string 'hello' and operate on the content coming from stdin

Any help would be appreciated.

Answer 1

It seems to be quite OK. Maybe you could close some fds after dup2:

// in child process
dup2(fd[0], STDIN_FILENO);
close(fd[0]);
close(fd[1]);

EDIT:

There seems to be typo: "/bin/grep/"

It should be: "/bin/grep"