I am trying to implement a linux shell that supports piping. I have already done simple commands, commands running in background, redirections, but piping is still missing.

I have already read about it and seen some snippets of code, but still haven't been able to sort out a working solution.

What I have so far:

int fd[2];

pid_t pid = fork();

if (pid == -1)  
   return -1;  

if (pid == 0)  
{  
   dup2(0, fd[0]);
   execlp("sort", "sort", NULL);
}  

I am a novice programmer, as you can probably tell, and when I am programming something I don't know much about, this being obviously the case, I like to start with something really easy and concrete and then build from there.

So, before being able to implement three and more different commands in pipeline, I would like to be able to compute "ls names.txt | sort" or something similiar, in which names.txt is a file of names alfabetically unordered.

Thanks.