Error in reading from the pipe - linux

Question

I am getting unusual results while writing and reading from a pipe. The runtime error is Program terminated by signal: 13. I searched about this error and found that this error is due to there are no readers to read from pipe while i am reading from the pipe in the child process. Here is my code:
#include <sys/types.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#define BUFFER_SIZE 50
#define READ_END 0
#define WRITE_END 1
int main()
{
int pipe_fd[2];
pid_t pid;
pid = fork();
char message[BUFFER_SIZE] = "Greetings";
char read_message[BUFFER_SIZE];
if( pipe(pipe_fd) == -1)
{
perror("Error in creating the pipe \n");
exit(-1);
}
if(pid==-1)
{
perror("Error in creating the child! \n");
exit(-1);
}
if(pid==0) // Child process
{
close(pipe_fd[WRITE_END]);
read(pipe_fd[READ_END], read_message , BUFFER_SIZE);
printf("The message read by the child is: %s", read_message);
close(pipe_fd[READ_END]);
}
if(pid>0) // Parent process
{
close(pipe_fd[READ_END]); //Closing the read end of the pipe
write(pipe_fd[WRITE_END], message, BUFFER_SIZE); // Writing to pipe on write_end
close(pipe_fd[WRITE_END]);
}
return 0;
}
Any suggestions how to solve this runtime error?

Answer 1

You need to open your pipe before you fork a child process. Otherwise your processes aren't talking to the same pipe.
Thus move your pipe creation code above the fork() call as follows:
if( pipe(pipe_fd) == -1)
{
perror("Error in creating the pipe \n");
exit(-1);
}
pid_t pid;
pid = fork();
char message[BUFFER_SIZE] = "Greetings";
char read_message[BUFFER_SIZE];
if(pid==-1)
{
perror("Error in creating the child! \n");
exit(-1);
}