Pipes, dup2 and exec()

Question

I have to write a shell that can run pipes. For example commands like ls -l | wc -l\". I have successfully parsed the command given by the user as below:

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Answer 1

Well, a simple and efficient work arund for something like this is making a script with the pipe stuff and then calling the script with some exec command from your C code.

script.sh

#!/bin/sh
ls -l | wc -l

And the you just do in your C program something like this

char *argv[] = {"script.sh", NULL};
execv(argv[0], argv);

Note that you'll have to have the script.sh in the same directory of your C program.