Pipeline Executor with Delimiters

This project implements a small command-line utility in C that executes two programs connected via a pipeline, using a custom ;; delimiter to separate commands.

Features

• Runs two commands, connected with a pipe:
  • The first command’s output is sent to the second command’s input.
• Uses ;; as a custom delimiter to split commands.
• Forks and executes each command using execvp.
• Tracks process IDs and command names in a linked list.
• Prints the name of each command that terminates successfully (exit status 0).
• Cleans up dynamically allocated memory for process tracking.

How It Works

1. Parses command-line arguments and splits them into separate commands using ;; as a delimiter.
2. Creates a pipe before forking processes.
3. For the first process:
   • Closes the read end of the pipe.
   • Redirects stdout to the write end of the pipe.
4. For the second process:
   • Closes the write end of the pipe.
   • Redirects stdin to the read end of the pipe.
5. Executes commands via execvp.
6. Waits for all child processes to finish.
7. Prints the names of commands that exited with status 0.

Usage

Compile:

git clone https://git.scratko.xyz/parallel-progs-by-args
cd parallel-progs-by-args
gcc -o pipeline_exec parallel_progs_by_args.c

Run with two commands separated by ;;

Example

./pipeline_exec echo hello world ;; tr a-z A-Z

This will:

• Run echo hello world, sending its output into tr a-z A-Z.
• Print the names of commands that executed successfully.

Notes

• Requires at least one ;; delimiter to separate commands.
• Currently supports exactly two commands in the pipeline.
• Command names in output are taken from the original arguments, not from the executed binary name after execvp.