https://github.com/nabilac27/42-pipex
pipex is a C program that simulates a shell pipeline, using pipes and process management to execute commands, handle file redirection, and facilitate inter-process communication.
https://github.com/nabilac27/42-pipex
command-execution concurency environment-variables error-handling file-descriptor file-handling input-output inter-process-communication memory-management pipeline pipes process-management redirection string-manipulation
Last synced: about 1 month ago
JSON representation
pipex is a C program that simulates a shell pipeline, using pipes and process management to execute commands, handle file redirection, and facilitate inter-process communication.
- Host: GitHub
- URL: https://github.com/nabilac27/42-pipex
- Owner: nabilac27
- Created: 2025-01-19T10:06:13.000Z (5 months ago)
- Default Branch: main
- Last Pushed: 2025-04-10T02:15:23.000Z (2 months ago)
- Last Synced: 2025-04-10T03:24:31.619Z (2 months ago)
- Topics: command-execution, concurency, environment-variables, error-handling, file-descriptor, file-handling, input-output, inter-process-communication, memory-management, pipeline, pipes, process-management, redirection, string-manipulation
- Language: C
- Homepage:
- Size: 1.49 MB
- Stars: 0
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: docs/README.md
Awesome Lists containing this project
README
# **pipex**
The **pipex** project is a C program that simulates a shell pipeline.
It uses pipes to connect commands, handles file redirection, and manages multiple processes.
The program takes two input files and a set of commands, then pipes the commands together and outputs the result.
## **Key Concepts**
- **Pipes**: Used to pass the output of one command as input to another.
- **Process Management**: The program uses `fork()` to create child processes to execute commands, with communication happening through pipes.
- **File Redirection**: Reads from or writes to files by redirecting input/output.
- **Environment Variables**: Uses the `PATH` variable to locate commands in system directories.
- **Error Handling**: Displays an error message and exits the program if something goes wrong (e.g., invalid commands or failure to create pipes).
## How to Run
#### **Make the project**:
To compile the `pipex` project, run the following command:
```bash
$ make
```
#### **Run the program**:
To run the program, use the following format:
```bash
$ ./pipex file1 cmd1 cmd2 file2
```
- file1 is the input file for the first command.
- cmd1 is the first command to execute.
- cmd2 is the second command to execute.
- file2 is the output file where the result of the pipeline will be written.
#### **Example**:
```bash
$ ./pipex input.txt "cat" "grep keyword" output.txt
```
#### **Rebuild**:
To rebuild the project from scratch (after using fclean), run:
```bash
$ make re
```
---
## **Functions Overview**
| **Function** | **Description** |
|-----------------------------------------|-----------------|
| `left_process(char *argv[], char *envp[], int fd[])` | Executes the first command in the pipeline and manages its redirection. |
| `right_process(char *argv[], char *envp[], int fd[])` | Executes the second command in the pipeline and manages its redirection. |
| `execute_cmd(char *cmd, char *envp[])` | Finds and runs a command by checking the system's `PATH`. |
| `get_path(char *cmd, char *envp[])` | Finds the full path of a command in the `PATH` directories. |
| `error_message(char *message)` | Displays an error message and exits the program if something goes wrong. |