books/apue/setvbuf.c

   1 /*
   2  * setvbuf() usage example
   3  */
   4 #include <stdio.h>
   5 #include <string.h>
   6 #include <stdlib.h>
   7
   8 int main(void)
   9 {
  10         int err;
  11         FILE *file;
  12         char buf[BUFSIZ];
  13
  14         /* open the stream */
  15         file = fopen("./buf_test2.txt", "w+");
  16         if (!file) {
  17                 fprintf(stderr, "file cannot be openned\n");
  18                 exit(1);
  19         }
  20
  21         /* set the stream buffer and the it as fully-buffered */
  22         memset(buf, '\0', sizeof(buf));
  23         err = setvbuf(file, buf, _IOFBF, sizeof(buf));
  24         if (err) {
  25                 fprintf(stderr, "sevbuf() failed\n");
  26                 exit(1);
  27         }
  28
  29         /* write data and exit */
  30         fprintf(file, "Go, go! Goooooo Jhonny go, go! Goooooo Jhonny go, go!\n");
  31         fclose(file);
  32
  33         /* shows the contents of 'buf' */
  34         fprintf(stdout, "buf: %s", buf);
  35
  36         return 0;
  37 };