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- // 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 <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);
- 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);
- 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);
- 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_
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