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   FILE* f = fdopen(fd, "w");
  17   if (f == NULL) err(EX_IOERR, "Couldn't open temporary file");
  18   reverse_file(input_file, f);
  19   if (fclose(f) == EOF) err(EX_IOERR, "Couldn't close temporary file");
  20   return temp_filename;
  21 }
  22
  23 void test_reverse_twice_is_the_same() {
  24   char* intermediate = reverse_to_temp_file(test_file);
  25   char* back_to_normal = reverse_to_temp_file(intermediate);
  26
  27   FILE* f1 = fopen(test_file, "r");
  28   if (f1 == NULL) err(EX_IOERR, "Couldn't open test file");
  29   FILE* f2 = fopen(back_to_normal, "r");
  30   if (f2 == NULL) err(EX_IOERR, "Couldn't open twice-reversed temp file");
  31
  32   for (int pos = 0; ; pos++) {
  33     int c1 = fgetc(f1);
  34     int c2 = fgetc(f2);
  35     if (c1 == EOF && ferror(f1)) err(EX_IOERR, "Error reading test file");
  36     if (c2 == EOF && ferror(f2)) err(EX_IOERR, "Error reading twice-reversed temp file");
  37     if (c1 != c2) {
  38       errx(EX_SOFTWARE, "Unexpected difference found at offset %d after reversing twice.  "
  39                         "Expected %d but found %d", pos, c1, c2);
  40     }
  41     if (c1 == EOF) break;
  42   }
  43
  44   if (fclose(f1) != 0) err(EX_IOERR, "Couldn't close test file");
  45   if (fclose(f2) != 0) err(EX_IOERR, "Couldn't close twice-reversed temp file");
  46   if (unlink(intermediate) == -1) err(EX_IOERR, "Couldn't remove intermediate temp file");
  47   if (unlink(back_to_normal) == -1) err(EX_IOERR, "Couldn't remove twice-reversed temp file");
  48   free(intermediate);
  49   free(back_to_normal);
  50 }
  51
  52 int main() {
  53   test_reverse_twice_is_the_same();
  54   puts("PASS");
  55   return 0;
  56 }