git.scottworley.com Git - overonion/blob - reverse_test.c

   1 #include "reverse_lib.h"
   2
   3 #include <err.h>
   4 #include <stdio.h>
   5 #include <stdlib.h>
   6 #include <string.h>
   7 #include <sysexits.h>
   8 #include <unistd.h>
   9
  10 static const char test_file[] = "reverse.c";
  11
  12 char* reverse_to_temp_file(const char* input_file) {
  13   char* temp_filename = strdup("/tmp/reverse_test.XXXXXX");
  14   int fd = mkstemp(temp_filename);
  15   if (fd == -1) err(EX_IOERR, "Couldn't make a temporary file");
  16   reverse_file(input_file, fd);
  17   if (close(fd) == -1) err(EX_IOERR, "Couldn't close temporary file");
  18   return temp_filename;
  19 }
  20
  21 void test_reverse_twice_is_the_same() {
  22   char* intermediate = reverse_to_temp_file(test_file);
  23   char* back_to_normal = reverse_to_temp_file(intermediate);
  24
  25   FILE* f1 = fopen(test_file, "r");
  26   if (f1 == NULL) err(EX_IOERR, "Couldn't open test file");
  27   FILE* f2 = fopen(back_to_normal, "r");
  28   if (f2 == NULL) err(EX_IOERR, "Couldn't open twice-reversed temp file");
  29
  30   for (int pos = 0; ; pos++) {
  31     int c1 = fgetc(f1);
  32     int c2 = fgetc(f2);
  33     if (c1 == EOF && ferror(f1)) err(EX_IOERR, "Error reading test file");
  34     if (c2 == EOF && ferror(f2)) err(EX_IOERR, "Error reading twice-reversed temp file");
  35     if (c1 != c2) {
  36       errx(EX_SOFTWARE, "Unexpected difference found at offset %d after reversing twice.  "
  37                         "Expected %d but found %d", pos, c1, c2);
  38     }
  39     if (c1 == EOF) break;
  40   }
  41
  42   if (fclose(f1) != 0) err(EX_IOERR, "Couldn't close test file");
  43   if (fclose(f2) != 0) err(EX_IOERR, "Couldn't close twice-reversed temp file");
  44   if (unlink(intermediate) == -1) err(EX_IOERR, "Couldn't remove intermediate temp file");
  45   if (unlink(back_to_normal) == -1) err(EX_IOERR, "Couldn't remove twice-reversed temp file");
  46   free(intermediate);
  47   free(back_to_normal);
  48 }
  49
  50 int main() {
  51   test_reverse_twice_is_the_same();
  52   puts("PASS");
  53   return 0;
  54 }