3. Parent to Child Communication

pravjot

3. Parent to Child Communication

Write a program where the parent process writes a message to the pipe, and the child process reads the message from the pipe and prints it.

gaurav133232

#include<stdio.h>
#include<stdlib.h>
#include<unistd.h>
int main()
{
   int pipefd[2];
   int data;
   char buf[BUFSIZ+1];
   if(pipe(pipefd)==0)
   {
   pid_t ret = fork();
   if(ret == (pid_t)-1)
   {
       perror("fork");
   }
   else if(ret == 0)
   {
       data = read(pipefd[0],buf,sizeof(buf));
       printf("Child process having pid:%d",getpid());
       printf("Read %d bytes:%s\n",data,buf);
       exit(EXIT_SUCCESS);
   }
   else
   {
       printf("Parent process having pid:%d",getpid());
       data = write(pipefd[1],"Hello world\n",14);
       printf("wrote %d bytes:%s\n",data,buf);
       exit(EXIT_SUCCESS);
   }
       printf("pipe created succesfully.\n");
       exit(EXIT_SUCCESS);
   }
   else if(pipe(pipefd)!=0)
   {
       perror("pipe");
       exit(EXIT_FAILURE);
   }
   return 0;
}

raj.kiran

   #include<stdio.h>
   #include<stdlib.h>
   #include<unistd.h>
   #include<string.h>

2 int main()

3 {
4         int *pipes;
5         int ret,fret,wret;
6         char wbuff[]="Live Let Live",rbuff[50];
7         printf("FILE: %s -> %s:Begins\n",__FILE__,__func__);
8         pipes=(int*)malloc(sizeof(int)*2);
9         if(!pipe)
10         {
11                 perror("malloc");
12                 exit(EXIT_FAILURE);
13         }
14         ret=pipe(pipes);
15         if(ret==-1)
16         {
17                 perror("pipe");
18                 exit(EXIT_FAILURE);
19         }
20         printf("Pipe created successfully\n");
21         fret=fork();
22         if(fret==-1)
23         {
24                 perror("fork");
25                 exit(EXIT_FAILURE);
26         }
27         else if(fret==0)
28         {
29                 printf("This is child process with pid:%d\n",getpid());
30                 wret=read(*(pipes),rbuff,50);
31                 if(wret==-1)
32                 {
33                         perror("write");
34                         exit(EXIT_FAILURE);
35                 }
36                 printf("Read successfully from the pipe:%s\n",rbuff);
37         }
38         else
39         {
40                 printf("This is Parent process with pid:%d\n",getpid());
41                 wret=write(*(pipes+1),wbuff,strlen(wbuff));
42                 if(wret==-1)
43                 {
44                         perror("write");
45                         exit(EXIT_FAILURE);
46                 }
47                 printf("String:%s, successfully written into the pipe\n",wbuff);
48         }
49         printf("FILE: %s -> %s:Ends\n",__FILE__,__func__);
50         return 0;
51 }

bhatnagarharsh37

#include"headers.h"

2 #include"declarations.h"

3

4 int main()

5 {

6 int fret,wret;

7 int *pret;

8 char r;

9 char buff[]="she sells she shell on the she shore";

10 char rbuf[50];

11 printf("%s: __BEGIN__\n", __func__);

12

13 pret=createpipe();

14 fret=fork();

15 switch(fret)

16 {

17 case -1:

18 perror("fork");

19 exit(EXIT_FAILURE);

20 case 0:

21 printf("hello i am child\n");

22 printf("pipe rfd:%d\n",*(pret+0));

23 printf("pipe wfd:%d\n",*(pret+1));

24 memset(rbuf,'\0',50);

25 r=read(*(pret+0),rbuf,50);

26 if(!r)

27 {

28 perror("read");

29 exit(EXIT_FAILURE);

30 }

31 printf("read by child:%s\n",rbuf);

32 break;

33 default:

34 printf("hello i am parent\n");

35 printf("pipe rfd:%d\n",*(pret+0));

36 printf("pipe wfd:%d\n",*(pret+1));

37 wret=write(*(pret+1),buff,strlen(buff));

38 if(!wret)

39 {

40 perror("write");

41 exit(EXIT_FAILURE);

42 }

43

44 break;

45 }

46

47

48 printf("%s: __END__\n", __func__);

49 return 0;

50 }

abhinandan2971verma

main.c

#include"../common/headers.h"

#include"declaration.h"

int main()

{

int fret,ret;

int *pipe;

char buff[]="hello to world of programming ";

printf("%s__begin__\n",__func__);

pipe=creat_pipe();

printf("pipe read file descriptor===%d\n",*(pipe+0));

printf("pipe write file descriptor===%d\n",*(pipe+1));

switch(fret)

fret=fork();

{

case -1:

perror("fork");

free(pipe);

exit(EXIT_FAILURE);

case 0:

printf("this is child process \n");

printf("pid==%d \n",getpid());

ret=read(*(pipe+0),buff,50);

if(ret==-1)

{

perror("read");

free(pipe);

exit(EXIT_FAILURE);

}

printf("read %d bytes from parent process \n",ret);

printf("contents are %s\n",buff);

break;

abhinandan2971verma

main(continue)

default:

printf("this is parent process \n");

printf("pid==%d \n",getpid());

ret=write(*(pipe+1),buff,strlen(buff));

if(ret==-1)

{

perror("write");

free(pipe);

exit(EXIT_FAILURE);

}

printf("write %d bytes to child process \n",ret);

break;

}

printf("%s__end__\n",__func__);

return 0;

}

abhinandan2971verma

creat_pipe.c

int* creat_pipe()

{

int ret;

int *arr;

printf("%s__begin__\n",__func__);

arr=(int*)malloc(sizeof(int)*2);

if(!arr)

{

perror("malloc");

exit(EXIT_FAILURE);

}

if(pipe(arr)==0)

printf("PIPE CREATED SUCCESFULLY \n");

else

{

perror("pipe");

free(arr);

exit(EXIT_FAILURE);

}

printf("%s__end__\n",__func__);

return arr;

}

3. Parent to Child Communication

3. Parent to Child Communication

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