write a program to create a child process. Send the command to child process and execute there and return the result to the parent by using IPC using pipes.

write a program  to create a child process. Send the command to child process and execute there and return the result to the parent by using IPC using pipes.

main()

{

   char *one[3],*two[2];

   int ret;

   one[0]=”ls”;

   one[1]=”-il”;

   one[2]=(char*)0;

   two[0]=”sort”;

   two[1]=(char*)0;

   ret=join(one,two);

    printf(“ join returned %d\n”,ret);

     exit(0);

}

  int join (com1,com2)

   char *com1[],*com2[]

{

  int p[2],status;

   switch(fork())

  {

 case -1:

   perror(“error”);

case 0:

     break;

default:

    wait(&status);

  return (status);

}

if (pipe(p) < 0)

   perror(“pipe call in join “);

switch(fork())

  {

   case -1:

   perror(“ 2^nd fork call in join “);

 case 0:

   close(1);

  dup(p[1]);

 close(p[0]);

close(p[1]);

execl(“/bin/ls”,com1[0],com1[1],com1[2]);

perror(“ 1^st execvp call in join”);

default:

    close(0);

    dup(p[0]);

   close(p[0]);

close(p[1]);

execl(“/bin/sort”,com2[0],com2[1]);

perror(“2^nd execvp call in join”);

}

}

6. Write a program to establish the message communication between the child and parent process using pipes.

#include<stdio.h>

main()

{

  int pp[2],pc[2],j,pid;

  char msg1[20];

  char msg2[20];

  char msg3[20];

pipe(pp);

pipe(pc);

pid=fork();

if (pid==0)

{

  close(pp[1]);

  close(pc[0]);

  write(pc[1],”hello daddy”,12);

  read (pp[0],msg2,12);

  printf(“%s\n”,msg2);

write(pc[1],”Thank you papa”,14);

}

else

{

  close(pp[0]);

close(pc[1]);

read(pc[0],msg1,12);

printf(“%s\n”,msg1);

write(pp[1],”hello baby”,12);

read(pc[0],msg3,14);

printf(“%s\n”,msg3);

}

}