[SOLVED] IPC using pipes

Hey I was going through this code for IPC. The program creates three processes, in parent we create a pipe, in process A we take a string input and finally in process B we reverse that string.
I am stuck on the dup2 part. I know that dup2 is redirecting input and output to p_des[0] and p_des[1]. but I am not able to understand that how the rev_str part is using the same string taken input by get_str part.

************PARENT PROCESS**********************
#include <stdio.h>
#include <ctype.h>
main()
{
int p_des[2];
pipe( p_des ); /* The pipe descriptor */
printf("Input a string \n");
if ( fork () == 0 )
{
dup2(p_des[1], 1);
close(p_des[0]); /* process-A closing read end of the pipe */
execlp("./get_str", "get_str", 0);
/*** exit(1); ***/
}
else
if ( fork () == 0 )
{
dup2(p_des[0], 0);
close(p_des[1]); /* process-B closing write end of the pipe */
execlp("./rev_str", "rev_str", 0);
/*** exit(1); ****/
}
else
{
close(p_des[1]); /* parent closing both the ends of pipe */
close(p_des[0]);
wait(0);
wait(0);
}
fflush(stdout);
}

****PROCESS A*****************
get_str.c
#include <stdio.h>
#include <ctype.h>
void get_str(str)
char str[];
{
char c;
int ic;
c = getchar();
ic = 0;
while ( ic < 10 && ( c != EOF && c != '\n' && c != '\t' ))
{
str[ic] = c;
c = getchar();
ic++;
}
str[ic] = '\0';
return;
}

************PROCESS B*******************
rev_str.c
void rev_str(str1, str2)
char str1[];
char str2[];
{
char c;
int ic;
int rc;
ic = 0;
c = str1[0];
while( ic < 10 && (c != EOF && c != '\0' && c != '\n') )
{
ic++;
c = str1[ic];
}
str2[ic] = '\0';
rc = ic - 1;
ic = 0;
while (rc-ic > -1)
{
str2[rc-ic] = str1[ic];
ic++;
}
return;
}

int dup2(int fildes, int fildes2);
In dup2(), the value of the new descriptor fildes2 is specified. If this descriptor is already in use, the descriptor is first deallocated as if a close(2) call had been done first.
dup2() copies the file descriptor. In this case it is copying the file descriptor of stdout in p_des[1] and stdin in p_des[0].
get_str and rev_str are separate C programs lying in same directory.
In the program given above, we spawn a two child processes and populate their code segment with the programs get_str.c and rev_str.c .

please use [code][/code] to keep formatting.
dup will not redirect, but duplicate file descriptor.
process A will read the pipe by getchar and process B should send the string into the pipe, but I cannot find that part of the code (probably a putchar)

Process A is not reading the pipe...we have closed the reading end of pipe in
{
dup2(p_des[1], 1);
close(p_des[0]); /* process-A closing read end of the pipe */
execlp("./get_str", "get_str", 0);
/*** exit(1); ***/
}

ok, in process B there is no code to read or write the pipe or stdin/stdout.
in process A you have getchar which will read stdin, but actually stdout is duped (as you wrote), so there is no connection between A and B. Also there is no main (for A and B) posted, so something is missing....

Solved: In process A after getting input through getchar we can printf the same so that it gets duped and Process B can easily read it thru stdin.