Question

How to Write a C program (for Linux/Unix) that:

–Creates a struct, where each instance can store one message.

–Forks a process.

–Creates 2+ messages, with contents of your choice, in the parent and sends them to the child via a named or anonymous pipe.

–Prints the contents of all received messages in the child process.

–If necessary, cleans up after the pipe.

Note (the subjects about signal and Pipes )

Answer 1

Code:

#include<stdio.h>
#include <unistd.h>
#include<malloc.h>
typedef struct pro
{
char *mes;
}proone;
int main()
{
char *message[3];
int fade[2];
proone one; //creating struct instance
proone two;
proone three;
one.mes="Welcome";
message[0]=one.mes;
two.mes="to";
message[1]=two.mes;
three.mes="Chegg";
message[2]=three.mes;
fork(); //for a process
pipe(fade); // creating a pipe with reading and writing end
int i;
if(fork()!=0)
{
close(fade[0]); //close reading end before writing
for(i=0;i<3;i++)
{
write(fade[1],&message[i],sizeof(message[i]));
printf("parent(%d) sends %s\n",getpid(),message[i]);
}
close(fade[1]); //close writing end of the pipe
}
else
{
close(fade[1]); //close writing end of the pipe
for(i=0;i<3;i++)
{
read(fade[0],&message[i],sizeof(message[i])); // read by reading end of the pipe
printf("child(%d) receives %s\n",getpid(),message[i]);
}
close(fade[0]); //close reading end of the pipe
}
return 0;
}

Output:

parent(18) sends Welcome
parent(18) sends to
parent(18) sends Chegg
child(20) receives Welcome
child(20) receives to
child(20) receives Chegg
parent(19) sends Welcome
parent(19) sends to
parent(19) sends Chegg
child(21) receives Welcome
child(21) receives to
child(21) receives Chegg