compiler-rt/test/sanitizer_common/TestCases/Posix/fgetc_ungetc_getc.cpp

   1 // RUN: %clangxx -g %s -o %t && %run %t
   2
   3 #include <assert.h>
   4 #include <stdio.h>
   5
   6 int main(int argc, char **argv) {
   7   FILE *fp = fopen(argv[0], "r");
   8   assert(fp);
   9
  10   // the file should be at least one character long, always
  11   assert(fgetc(fp) != EOF);
  12   // POSIX guarantees being able to ungetc() at least one character
  13   assert(ungetc('X', fp) != EOF);
  14   // check whether ungetc() worked
  15   assert(getc(fp) == 'X');
  16
  17   assert(!fclose(fp));
  18   return 0;
  19 }