Exer4.6.c(undone)

//程序可以正常运行，但file.nohole始终没有东西写进去，为什么？

 

#include "apue.h"

#include <sys/types.h>

#include <sys/stat.h>

#include <fcntl.h>

 

 

int main(int argc, char *argv[]){

  FILE *fp1, *fp2; 

  char chr;

  int fd, count = 0;

 

  if(argc != 3)

    err_quit("Usage: %s <src> <dest>", argv[0]);

 

  if((fp1 = fopen(argv[1], "r")) == NULL)

    err_sys("fopen %s error", argv[1]);

  if((fd = open(argv[2], O_CREAT|O_EXCL|O_TRUNC, S_IRWXU|S_IRGRP)) < 0)

    err_sys("create %s error", argv[2]);

  if((fp2 = fdopen(fd, "rw")) == NULL)

    err_sys("transfer from filedes to file stream error");

  while((chr = getc(fp1)) != EOF){

    count++;

    if(!chr){

      continue;

    }

 

    putc(chr, stdout);

    printf("\ncount: %d\n", count);   

    putc(chr, fp2);

  }

  //  putc(EOF, stdout); // '?' printed

  putc(EOF, fp2);

  fflush(fp2);

  if(fclose(fp2) == EOF)

    err_sys("fclose fp2 error");

  exit(0);

}