021.c

/*
..........................................................................................................................................
Name : 030.c
Author : SHRUTI VERMA
Description : Write two programs so that both can communicate by FIFO -Use two way communications.
Date : 17 Sep 2025
..........................................................................................................................................
*/

#include<unistd.h>
#include<stdlib.h>
#include<stdio.h>
#include<sys/types.h>
#include<fcntl.h>
#include<sys/stat.h>

#define FIFO1 "fifo1"
#define FIFO2 "fifo2"

void reader(const char* fifo1, const char* fifo2) {
    int fd1, fd2;
      
    fd1 = open(fifo1, O_RDONLY);
    fd2 = open(fifo2, O_WRONLY);

    char msg[100];
    char buf[100];
    while(1) {
        int n = read(fd1, buf, sizeof(buf));
        buf[n] = '\0';
        printf("Data from writer : %s\n", buf);
        
        printf("Reader process : ");

        scanf(" %[^\n]", msg);
        write(fd2, msg, sizeof(msg));
    }
    
    close(fd1);         
    close(fd2);
}

void writer(const char* fifo1, const char* fifo2) {
   
    int fd1, fd2;
    fd2 = open(fifo1, O_WRONLY);
    fd1 = open(fifo2, O_RDONLY);
    

    char msg[100];
    char buf[100];
    while(1) {
        printf("Writer process : ");
        fflush(stdout);
        scanf(" %[^\n]", msg);
        write(fd2, msg, sizeof(msg));
        
        read(fd1, buf, sizeof(buf));
        buf[99] = '\0';
        printf("Data from reader : %s\n", buf);
    }
    
    close(fd1);     
    close(fd2);
}

int main() {

    int choice = 0;
    int fd1, fd2;
    mkfifo(FIFO1, 0666);
    mkfifo(FIFO2, 0666);
    printf("1. Writer process\n2. Reader process\nEnter your choice : ");
    scanf("%d", &choice);
    if(choice == 1) {
        writer(FIFO1, FIFO2);
    } else {
        reader(FIFO1, FIFO2);
    }
}

/*-----------------------------------------------OUTPUT-----------------------------------------------
terminal 1
vumma@vumma-VivoBook-15-ASUS-Laptop-X507UF:~/Desktop/SS/HOL2$ ./021.out
1. Writer process
2. Reader process
Enter your choice : 2
Data from writer : hello reader
Reader process : hi writer
Data from writer : what's the status?
Reader process : just doing some FIFO problem

terminal2
vumma@vumma-VivoBook-15-ASUS-Laptop-X507UF:~/Desktop/SS/HOL2$ ./021.out
1. Writer process
2. Reader process
Enter your choice : 1
Writer process : hello reader
Data from reader : hi writer
Writer process : what's the status?
Data from reader : just doing some FIFO problem
Writer process : 
*/