1 // Copyright 2011 The Kyua Authors. 2 // All rights reserved. 3 // 4 // Redistribution and use in source and binary forms, with or without 5 // modification, are permitted provided that the following conditions are 6 // met: 7 // 8 // * Redistributions of source code must retain the above copyright 9 // notice, this list of conditions and the following disclaimer. 10 // * Redistributions in binary form must reproduce the above copyright 11 // notice, this list of conditions and the following disclaimer in the 12 // documentation and/or other materials provided with the distribution. 13 // * Neither the name of Google Inc. nor the names of its contributors 14 // may be used to endorse or promote products derived from this software 15 // without specific prior written permission. 16 // 17 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 18 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 19 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 20 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 21 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 22 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 23 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 27 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 29 #include "utils/stream.hpp" 30 31 #include <fstream> 32 #include <iostream> 33 #include <sstream> 34 #include <stdexcept> 35 36 #include "utils/format/macros.hpp" 37 #include "utils/fs/path.hpp" 38 #include "utils/sanity.hpp" 39 40 namespace fs = utils::fs; 41 42 43 namespace { 44 45 46 /// Constant that represents the path to stdout. 47 static const fs::path stdout_path("/dev/stdout"); 48 49 50 /// Constant that represents the path to stderr. 51 static const fs::path stderr_path("/dev/stderr"); 52 53 54 } // anonymous namespace 55 56 57 /// Opens a new file for output, respecting the stdout and stderr streams. 58 /// 59 /// \param path The path to the output file to be created. 60 /// 61 /// \return A pointer to a new output stream. 62 std::auto_ptr< std::ostream > 63 utils::open_ostream(const fs::path& path) 64 { 65 std::auto_ptr< std::ostream > out; 66 if (path == stdout_path) { 67 out.reset(new std::ofstream()); 68 out->copyfmt(std::cout); 69 out->clear(std::cout.rdstate()); 70 out->rdbuf(std::cout.rdbuf()); 71 } else if (path == stderr_path) { 72 out.reset(new std::ofstream()); 73 out->copyfmt(std::cerr); 74 out->clear(std::cerr.rdstate()); 75 out->rdbuf(std::cerr.rdbuf()); 76 } else { 77 out.reset(new std::ofstream(path.c_str())); 78 if (!(*out)) { 79 throw std::runtime_error(F("Cannot open output file %s") % path); 80 } 81 } 82 INV(out.get() != NULL); 83 return out; 84 } 85 86 87 /// Gets the length of a stream. 88 /// 89 /// \param is The input stream for which to calculate its length. 90 /// 91 /// \return The length of the stream. This is of size_t type instead of 92 /// directly std::streampos to simplify the caller. Some systems do not 93 /// support comparing a std::streampos directly to an integer (see 94 /// NetBSD 1.5.x), which is what we often want to do. 95 /// 96 /// \throw std::exception If calculating the length fails due to a stream error. 97 std::size_t 98 utils::stream_length(std::istream& is) 99 { 100 const std::streampos current_pos = is.tellg(); 101 try { 102 is.seekg(0, std::ios::end); 103 const std::streampos length = is.tellg(); 104 is.seekg(current_pos, std::ios::beg); 105 return static_cast< std::size_t >(length); 106 } catch (...) { 107 is.seekg(current_pos, std::ios::beg); 108 throw; 109 } 110 } 111 112 113 /// Reads a whole file into memory. 114 /// 115 /// \param path The file to read. 116 /// 117 /// \return A plain string containing the raw contents of the file. 118 /// 119 /// \throw std::runtime_error If the file cannot be opened. 120 std::string 121 utils::read_file(const fs::path& path) 122 { 123 std::ifstream input(path.c_str()); 124 if (!input) 125 throw std::runtime_error(F("Failed to open '%s' for read") % path); 126 return read_stream(input); 127 } 128 129 130 /// Reads the whole contents of a stream into memory. 131 /// 132 /// \param input The input stream from which to read. 133 /// 134 /// \return A plain string containing the raw contents of the file. 135 std::string 136 utils::read_stream(std::istream& input) 137 { 138 std::ostringstream buffer; 139 140 char tmp[1024]; 141 while (input.good()) { 142 input.read(tmp, sizeof(tmp)); 143 if (input.good() || input.eof()) { 144 buffer.write(tmp, input.gcount()); 145 } 146 } 147 148 return buffer.str(); 149 } 150