| // Copyright (c) 2016 Google Inc. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| #ifndef TOOLS_IO_H_ |
| #define TOOLS_IO_H_ |
| |
| #include <cstdint> |
| #include <cstdio> |
| #include <cstring> |
| #include <vector> |
| |
| // Appends the content from the file named as |filename| to |data|, assuming |
| // each element in the file is of type |T|. The file is opened with the given |
| // |mode|. If |filename| is nullptr or "-", reads from the standard input, but |
| // reopened with the given mode. If any error occurs, writes error messages to |
| // standard error and returns false. |
| template <typename T> |
| bool ReadFile(const char* filename, const char* mode, std::vector<T>* data) { |
| const int buf_size = 1024; |
| const bool use_file = filename && strcmp("-", filename); |
| if (FILE* fp = |
| (use_file ? fopen(filename, mode) : freopen(nullptr, mode, stdin))) { |
| T buf[buf_size]; |
| while (size_t len = fread(buf, sizeof(T), buf_size, fp)) { |
| data->insert(data->end(), buf, buf + len); |
| } |
| if (ftell(fp) == -1L) { |
| if (ferror(fp)) { |
| fprintf(stderr, "error: error reading file '%s'\n", filename); |
| if (use_file) fclose(fp); |
| return false; |
| } |
| } else { |
| if (sizeof(T) != 1 && (ftell(fp) % sizeof(T))) { |
| fprintf( |
| stderr, |
| "error: file size should be a multiple of %zd; file '%s' corrupt\n", |
| sizeof(T), filename); |
| if (use_file) fclose(fp); |
| return false; |
| } |
| } |
| if (use_file) fclose(fp); |
| } else { |
| fprintf(stderr, "error: file does not exist '%s'\n", filename); |
| return false; |
| } |
| return true; |
| } |
| |
| // Writes the given |data| into the file named as |filename| using the given |
| // |mode|, assuming |data| is an array of |count| elements of type |T|. If |
| // |filename| is nullptr or "-", writes to standard output. If any error occurs, |
| // returns false and outputs error message to standard error. |
| template <typename T> |
| bool WriteFile(const char* filename, const char* mode, const T* data, |
| size_t count) { |
| const bool use_stdout = |
| !filename || (filename[0] == '-' && filename[1] == '\0'); |
| if (FILE* fp = (use_stdout ? stdout : fopen(filename, mode))) { |
| size_t written = fwrite(data, sizeof(T), count, fp); |
| if (count != written) { |
| fprintf(stderr, "error: could not write to file '%s'\n", filename); |
| if (!use_stdout) fclose(fp); |
| return false; |
| } |
| if (!use_stdout) fclose(fp); |
| } else { |
| fprintf(stderr, "error: could not open file '%s'\n", filename); |
| return false; |
| } |
| return true; |
| } |
| |
| #endif // TOOLS_IO_H_ |