xref: /aosp_15_r20/external/openscreen/testing/util/read_file.cc (revision 3f982cf4871df8771c9d4abe6e9a6f8d829b2736)
1*3f982cf4SFabien Sanglard // Copyright 2019 The Chromium Authors. All rights reserved.
2*3f982cf4SFabien Sanglard // Use of this source code is governed by a BSD-style license that can be
3*3f982cf4SFabien Sanglard // found in the LICENSE file.
4*3f982cf4SFabien Sanglard 
5*3f982cf4SFabien Sanglard #include "testing/util/read_file.h"
6*3f982cf4SFabien Sanglard 
7*3f982cf4SFabien Sanglard #include <stdio.h>
8*3f982cf4SFabien Sanglard 
9*3f982cf4SFabien Sanglard namespace openscreen {
10*3f982cf4SFabien Sanglard 
ReadEntireFileToString(absl::string_view filename)11*3f982cf4SFabien Sanglard std::string ReadEntireFileToString(absl::string_view filename) {
12*3f982cf4SFabien Sanglard   FILE* file = fopen(filename.data(), "r");
13*3f982cf4SFabien Sanglard   if (file == nullptr) {
14*3f982cf4SFabien Sanglard     return {};
15*3f982cf4SFabien Sanglard   }
16*3f982cf4SFabien Sanglard   fseek(file, 0, SEEK_END);
17*3f982cf4SFabien Sanglard   long file_size = ftell(file);
18*3f982cf4SFabien Sanglard   fseek(file, 0, SEEK_SET);
19*3f982cf4SFabien Sanglard   std::string contents(file_size, 0);
20*3f982cf4SFabien Sanglard   int bytes_read = 0;
21*3f982cf4SFabien Sanglard   while (bytes_read < file_size) {
22*3f982cf4SFabien Sanglard     size_t ret = fread(&contents[bytes_read], 1, file_size - bytes_read, file);
23*3f982cf4SFabien Sanglard     if (ret == 0 && ferror(file)) {
24*3f982cf4SFabien Sanglard       return {};
25*3f982cf4SFabien Sanglard     } else {
26*3f982cf4SFabien Sanglard       bytes_read += ret;
27*3f982cf4SFabien Sanglard     }
28*3f982cf4SFabien Sanglard   }
29*3f982cf4SFabien Sanglard   fclose(file);
30*3f982cf4SFabien Sanglard 
31*3f982cf4SFabien Sanglard   return contents;
32*3f982cf4SFabien Sanglard }
33*3f982cf4SFabien Sanglard 
34*3f982cf4SFabien Sanglard }  // namespace openscreen
35