Function WriteToShardStatusFileIfNeeded

tests/gtest/gtest-all.cc:6823–6837

Reads the GTEST_SHARD_STATUS_FILE environment variable, and creates the file if the variable is present. If a file already exists at this location, this function will write over it. If the variable is present, but the file cannot be created, prints an error and exits.

// function will write over it. If the variable is present, but the file cannot
// be created, prints an error and exits.
void WriteToShardStatusFileIfNeeded() {
  const char* const test_shard_file = posix::GetEnv(kTestShardStatusFile);
  if (test_shard_file != nullptr) {
    FILE* const file = posix::FOpen(test_shard_file, "w");
    if (file == nullptr) {
      ColoredPrintf(COLOR_RED,
                    "Could not write to the test shard status file \"%s\" "
                    "specified by the %s environment variable.\n",
                    test_shard_file, kTestShardStatusFile);
      fflush(stdout);
      exit(EXIT_FAILURE);
    }
    fclose(file);
  }
}

// Checks whether sharding is enabled by examining the relevant
// environment variable values. If the variables are present,