4. Bidirectional Communication

pravjot

4. Bidirectional Communication

Extend the program to create two pipes: one for parent-to-child communication and another for child-to-parent communication. The parent sends a message to the child, the child modifies the message, and sends it back to the parent.

gaurav133232

#include<stdio.h>
#include<stdlib.h>
#include<unistd.h>
int main()
{
   int pipefd[2];
   int pipefd1[2];
   int data;
   int data1;
   char buf[BUFSIZ+1];
   char buf1[BUFSIZ+1];
   if(pipe(pipefd)==0 && pipe(pipefd1)==0)
   {
   pid_t ret = fork();
   pid_t ret1 = fork();
   if(ret == (pid_t)-1 || ret1 == (pid_t)-1)
   {
       perror("fork");
   }
   else if(ret == 0 || ret1 == 0)
   {
       data = read(pipefd[0],buf,sizeof(buf));
       data1 = write(pipefd1[1],"Bye",3);
       printf("Child process having pid:%d",getpid());
       printf("Read %d bytes:%s\n",data,buf);
       printf("wrote %d bytes:%s\n",data,buf1);
       exit(EXIT_SUCCESS);
   }
   else
   {
       printf("Parent process having pid:%d",getpid());
       data = write(pipefd[1],"Hello world\n",14);
       data1 = read(pipefd1[0],buf1,sizeof(buf1));
       printf("Read %d bytes:%s\n",data,buf1);
       printf("wrote %d bytes:%s\n",data,buf);
       exit(EXIT_SUCCESS);
   }
       printf("pipe created succesfully.\n");
       exit(EXIT_SUCCESS);
   }
   else if((pipe(pipefd) ||pipe(pipefd1))!=0)
   {
       perror("pipe");
       exit(EXIT_FAILURE);
   }
   return 0;
}

raj.kiran

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

#include<string.h>

int main()

{
       int *pipe1,*pipe2;
       int ret,fret,wret;
       char wbuff[]="Live Let Live",rbuff[50];
       char* res;
       res=(char*)malloc(sizeof(50));
       pipe1=(int*)malloc(sizeof(int)*2);
       pipe2=(int*)malloc(sizeof(int)*2);
       ret=pipe(pipe1);
       ret=pipe(pipe2);
       printf("Pipe created successfully\n");
       fret=fork();
       if(fret==-1)
        {
              perror("fork");
              exit(EXIT_FAILURE);
        }
       else if(fret==0)
        {
               printf("This is child process with pid:%d\n",getpid());
               wret=read(*(pipe1),rbuff,50);
               printf("parent:%s\n",rbuff);
               res=toUpper(rbuff);
               wret=write(*(pipe2+1),rbuff,strlen(rbuff));
        }
    else
        {
                printf("This is Parent process with pid:%d\n",getpid());
                wret=write(*(pipe1+1),wbuff,strlen(wbuff));

wret=read(*(pipe2),wbuff,strlen(wbuff));

                printf("child:%s\n",wbuff);
          }
          return 0;
}

message modification fucntion:

2 char* toUpper(char s[])
3 {
4         for(int i=0;i<strlen(s);i++)
5         {
6           if(s[i]>=97)
7           s[i]=s[i]-32;
8         }
9         return s;
10 }

PS:Removed all the error handling verifications.

abhinandan2971verma

FILENO 1 CONTAIN CREAT_PIPE FUNCTION

CREAT_PIPE()

#include"headers.h"

#include"declaration.h"

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;

}

abhinandan2971verma

FILE NO 2 CONTAIN MAIN FUNCTION

main()

#include"headers.h"

#include"declaration.h"

int main()

{

int fret,ret;

int *pipe1,*pipe2;

char Wbuff[50]="hello parent ";

char Rbuff[50];

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

pipe1=creat_pipe();

pipe2=creat_pipe();

printf("pipe read file descriptor for pipe1 ===%d\n",*(pipe1+0));

printf("pipe write file descriptor for pipe1===%d\n",*(pipe1+1));

printf("pipe read file descriptor for pipe2 ===%d\n",*(pipe2+0));

fret=fork();

switch(fret)

{

case -1:

perror("fork");

free(pipe1);

free(pipe2);

exit(EXIT_FAILURE);

case 0:

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

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

ret=read(*(pipe1+0),&Rbuff,50);

if(ret==-1)

{

perror("read");

free(pipe1);

free(pipe2);

exit(EXIT_FAILURE);

}

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

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

strcpy(Wbuff,"hello child");

ret=write(*(pipe2+1),&Wbuff,strlen(Wbuff));

if(ret==-1)

{

perror("write");

free(pipe1);

free(pipe2);

exit(EXIT_FAILURE);

}

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

break;

}

abhinandan2971verma

FILE2 CONTINUE

default:

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

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

ret=write(*(pipe1+1),&Wbuff,strlen(Wbuff));

if(ret==-1)

{

perror("write");

free(pipe1);

free(pipe2);

exit(EXIT_FAILURE);

}

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

ret=read(*(pipe2+0),&Rbuff,50);

if(ret==-1)

{

perror("read");

free(pipe2);

free(pipe1);

exit(EXIT_FAILURE);

}

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

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

break;

}

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

return 0;

}

bhatnagarharsh37

1 #include<stdio.h>
2 #include<stdlib.h>
3 #include<string.h>
4 #include<unistd.h>
5 #include<fcntl.h>
6
7 int* createpipe();
8
9 int main()
10 {
11 int fret,wret,rret,i,l;
12 int *p1,*p2;
13 char buff[]="she sell ";
14 char rbuff[50];
15 printf("%s: %s __BEGIN__\n ",__FILE__,__func__);
16 memset(rbuff,'\0',50);
17 p1=createpipe(); //createpipe()
18 p2=createpipe(); //createpipe()
19 fret=fork();
20 switch(fret)
21 {
22 case -1:
23 perror("fork failure");
24 exit(EXIT_FAILURE);
25 case 0:
26 printf("%s:%s:__Hello i am child__\n",__FILE__,__func__);
27 printf("rfd:%d\n",*(p2+0));
28 printf("wfd:%d\n",*(p2+1));
29 rret=read(*(p1+0),rbuff,50);
30 if(!rret)
31 {
32 perror("read");
33 exit(EXIT_FAILURE);
34 }
35 printf("successfully read from 1 pipe :%s\n",rbuff);
36 l=strlen(rbuff);
37 i=l;
38 printf("enter the modify message\n");
39 do{
40 *(rbuff+i) = getchar();
41 if(*(rbuff+i) == '\n')
42 break;
43 i++;
44 }while(1);
45 *(rbuff+i)='\0';
46 wret=write(*(p2+1),rbuff,50);
47 if(!wret)
48 {
49 perror("write");
50 exit(EXIT_FAILURE);
51 }
52 break;
53 default:
54 printf("%s:%s:__Hello i am parent__\n",__FILE__,__func__);
55 printf("rfd:%d\n",*(p1+0));
56 printf("wfd:%d\n",*(p1+1));
57 wret=write(*(p1+1),buff,strlen(buff));
58 if(!wret)
59 {
60 perror("write");
61 exit(EXIT_FAILURE);
62 }
63 printf("successfully write into 1 pipe\n");
64 rret=read(*(p2+0),rbuff,50);
65 if(!rret)
66 {
67 perror("read");
68 exit(EXIT_FAILURE);
69 }
70 printf("Successfully read from 2 pipe:%s\n",rbuff);
71 break;
72 }
73 printf("%s: %s __END__\n ",__FILE__,__func__);
74 return 0;
75 }

bhatnagarharsh37

1 #include<stdio.h>

2 #include<stdlib.h>

3 #include<unistd.h>

4

5 int* createpipe()

6 {

7 int ret;

8 int *p;

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

10 p=(int*)malloc(sizeof(int)*2);

11 if(!p)

12 {

13 perror("malloc");

14 exit(EXIT_FAILURE);

15 }

16

17 ret=pipe(p);

18 if(ret == -1)

19 {

20 perror("malloc");

21 exit(EXIT_FAILURE);

22 }

23

24

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

26 return p;

27 }

4. Bidirectional Communication

4. Bidirectional Communication

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