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Using pipes as file streams, fdopen()



Using pipes as file streams, fdopen()

#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>

#define MAXLINE         512

int main(void) {
 char line[MAXLINE];
 FILE *fpin  = {0};
 FILE *fpout = {0};
 pid_t child = -1;
 int fd[2] = {0};
 int i = 0;

 pipe(fd);

 if((child = fork()) == -1) {
  perror("fork");
  return 1;
 }

 if(child == 0) {
  close(fd[0]);

  fpout = fdopen(fd[1], "w");
  if(fpout == NULL) {
   fprintf(stderr, "Error - fdopen(child)\n");
   return 1;
  }

  for(i = 0; i < 10; i++)
   fprintf(fpout, "%s\n", "jeronimooo...");

  fclose(fpout);
  return 0;
 } else {
  close(fd[1]);

  fpin = fdopen(fd[0], "r");
  if(fpin == NULL) {
   fprintf(stderr, "Error - fdopen(parent)\n");
   return 1;
  }

  while(fgets(line, MAXLINE, fpin) != NULL)
   printf("%d: %s", i++, line);

  fclose(fpin);
 }

 return 0;
}