[SOLVED] I can't run second child in C (Fork Problem)

[ertan2002]

Hi everyone, I'm ertan and Im in new cpp programming in linux. I have one problem in my task.
Now,I created one parent and two children. I must create some value as random in child1 and child1 has to send these values to child2.Child2 must read them..
now,I cant create some random values and i can send them.But child2 doesnt work. I have two functions. One them is writing, another one is reading. Child2 uses reading function,but it doesnt work (child2 cant call it, because writing function in endless loop)
What i must do? I used wait,usleep... No way..
I attached my file and also there is code..
I'm waiting for your help..
Thank you..

 #include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <signal.h>
#include <stdarg.h>
#include <sys/types.h>
#include <string.h>
#include <iostream>
#include <sstream>
#include <string>
using std::ostringstream;
 
using namespace std;
 
 
void producer( int handle )
{
  int count = 0, total = 0;
  char buf[ 128 ];
int myVal=0;
  while ( 1 )
  {
 
    myVal=rand()%100;
 
      sprintf( buf, "%d\n",myVal );
 
      int ret = write( handle, buf, strlen( buf ) );
printf("handle %d  buf:  %s \n",handle,buf);
//getchar();
          if ( ret < 0 )
          {
               printf( "Writing Error in Pipe!" );
          exit( 1 );
          }
 
 
 
      printf( "Sending Number: %s\n", buf );
  }
}
 
 
void consumer( int handle )
{
//  int total = 0;
  char buf[ 128 ];
  int tmp=0;
  while ( 1 )
  {
      int ret = read( handle, buf, sizeof( buf ) );
      if ( ret < 0 )
      {
                printf( "Reading Error in pipe!" );
          exit( 1 );
      }
      buf[ ret ] = 0;
 
 
  }
   string str=(char*)buf;
 
   size_t found=0;
 
 
  int tmp1=0;
  int total=0;
  
  string str2;
 
 
    do{
      
     found=str.find_first_of("\n",found+1);
 
          str2 = str.substr(tmp1,found-tmp1);
    total += atoi(str2.c_str());
      cout<<"Recieved Number: " <<str2<< "\n"<<"Sum of Numbers: "<<total<<"\n";
      tmp1=found+1;
          
 
    }  while (found!=string::npos);
 
//semaphor
 
  }
main()
{ 
    
 int mypipe[ 2 ];
 
if ( pipe( mypipe ) < 0 )
{
   printf("Creating pipe Error!" );
     exit( 1 );
  }
  
  int myChild;
  int myChild2;
  
  myChild = fork();
  
 
  if (myChild <0) 
  {
     printf("can't fork"); 
     exit(1);
  } 
  
  else if (myChild == 0)
   {  // Child 1
   printf("child1\n");
     close( mypipe[ 0 ] );
      producer( mypipe[ 1] );
      
    }
    
    else  
    
    {
    
    printf("Parent: my pid = %d, parent pid = %d \n ", getpid(), getppid());
 
    myChild= fork();
        if (myChild == 0)
       { // Child2
       printf("child2\n");
     close( mypipe[ 1 ] );
      consumer( mypipe[ 0] );
 
            }           
    }
  return 0;
 
 
} 
  

[Rubberman]

In your consumer() function, you aren't breaking out of the read loop, so you never get to the data processing part.

void consumer( int handle ) 
{ 
//  int total = 0; 
  char buf[ 128 ]; 
  int tmp=0; 
  while ( 1 ) 
  { 
      int ret = read( handle, buf, sizeof( buf ) ); 
      if ( ret < 0 ) 
      { 
                printf( "Reading Error in pipe!" ); 
          exit( 1 ); 
      } 
      buf[ ret ] = 0; 
  }
// You never get here
.
.
.

[ertan2002]

Hi,Thank you for your reply. I already have solve this problem. I made mistake and i realized it later. I have just edited "while loop" and it works now..
Thank you for your attention..
Have a nice days..