A simple example demonstratin piping in C

pipe.c

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sys/wait.h>  

int main() {
    int pipefd[2]; // File descriptors for the pipe

    // Create the pipe
    if (pipe(pipefd) == -1) {
        perror("Pipe creation failed");
        exit(EXIT_FAILURE);
    }

    // Fork a child process
    pid_t pid = fork();

    if (pid == -1) {
        perror("Fork failed");
        exit(EXIT_FAILURE);
    }

    if (pid == 0) {
        // Child process (writer)

        // Close the read end of the pipe
        close(pipefd[0]);

        // Data to be sent
        const char *message = "Hello, Parent!";

        // Write data to the pipe
        write(pipefd[1], message, strlen(message));

        // Close the write end of the pipe
        close(pipefd[1]);

        exit(EXIT_SUCCESS);
    } else {
        // Parent process (reader)

        // Close the write end of the pipe
        close(pipefd[1]);

        // Buffer to store the received data
        char buffer[100];

        // Read data from the pipe
        ssize_t bytesRead = read(pipefd[0], buffer, sizeof(buffer));

        if (bytesRead == -1) {
            perror("Read failed");
            exit(EXIT_FAILURE);
        }

        // Close the read end of the pipe
        close(pipefd[0]);

        // Null-terminate the received data
        buffer[bytesRead] = '\0';

        printf("Received message from child: %s\n", buffer);

        // Wait for the child process to finish
        wait(NULL);

        exit(EXIT_SUCCESS);
    }

    return 0;
}