src/process3.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <string.h>
   4
   5 /* open/read/write/close */
   6 #include <fcntl.h>
   7
   8 /** If buffer is too small to hold entire string, it is incremented by this value */
   9 #define BUFFER_STEP 16
  10
  11 /**
  12  * Program grabs data from process1, calculates number of characters in each line
  13  * and pass the value to process3.
  14  */
  15 int main(void) {
  16         /** Named pipe used to communicate with process1 */
  17         char * read_pipe = "/tmp/process2pipe";
  18
  19         int read_descriptor;
  20
  21         int buffer = 0;
  22
  23         int i = 0;
  24         ssize_t count = 0;
  25
  26         /* Reading from process2 */
  27         read_descriptor = open(read_pipe, O_RDONLY);
  28
  29         int number_of_characters = 0;
  30
  31         while(1) {
  32                 /* Read data from input pipe */
  33                 count = read(read_descriptor, &buffer, sizeof(int));
  34
  35                 fprintf(stderr, "[%s] Fetched: %d bytes\n", "process3", count);
  36
  37                 if (count > 0) {
  38                         fprintf(stderr, "[%s] Process2 send: %d\n", "process3", buffer);
  39                 }
  40                 else {
  41                         break;
  42                 }
  43         }
  44
  45         close(read_descriptor);
  46
  47         return 0;
  48 }