git.scottworley.com Git - tl-append/blob - tl-append.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3
   4 #include "common.h"
   5
   6 const size_t BUF_SIZE = 1024;
   7
   8 static void read_line(char *buf) {
   9   if (fgets(buf, BUF_SIZE, stdin) == NULL) {
  10     if (ferror(stdin))
  11       die("I/O error reading line");
  12     if (feof(stdin)) {
  13       buf[0] = '\0'; /* Unclear if fgets does this already */
  14       return;
  15     }
  16     die("Unexpected error reading line");
  17   }
  18 }
  19
  20 static void write_line(const char *line) {
  21   FILE *f = fopen(FILENAME, "a");
  22   if (f == NULL)
  23     die_err("Error opening output file");
  24   if (fputs(line, f) == EOF)
  25     die("Error writing to output file");
  26   if (fclose(f) != 0)
  27     die_err("Error closing output file");
  28 }
  29
  30 int main() {
  31   char buf[BUF_SIZE];
  32   for (read_line(buf); buf[0]; read_line(buf)) {
  33     write_line(buf);
  34   }
  35   return 0;
  36 }