From d20431e11290320f04d62e26b9a7cbcefaf5480c Mon Sep 17 00:00:00 2001 From: Boris Kolpackov Date: Wed, 27 Apr 2016 19:05:23 +0200 Subject: Add temp_directory(), temp_path() --- NEWS | 2 + butl/path | 32 +++++++++++++ butl/path.cxx | 147 +++++++++++++++++++++++++++++++++++++++++++++++++++++++--- 3 files changed, 175 insertions(+), 6 deletions(-) diff --git a/NEWS b/NEWS index dfcbd6c..c459750 100644 --- a/NEWS +++ b/NEWS @@ -2,6 +2,8 @@ Version 0.4.0 * Add process::current_id(). + * Add temp_directory(), temp_path() utility functions. + Version 0.3.0 * Add SHA256 hash calculator based on code from the FreeBSD project. That diff --git a/butl/path b/butl/path index 07b05ca..df76f99 100644 --- a/butl/path +++ b/butl/path @@ -159,6 +159,20 @@ namespace butl static void current (string_type const&); + // Return the temporary directory. Throw std::system_error to report the + // underlying OS errors. + // + static string_type + temp_directory (); + + // Return a temporary name. The name is constructed by starting with the + // prefix followed by the process id following by a unique counter value + // inside the process. Throw std::system_error to report the underlying OS + // errors. + // + static string_type + temp_name (string_type const& prefix); + // Make the path real (by calling realpath(3)). Throw invalid_basic_path // if the path is invalid (e.g., some components do not exist) and // std::system_error to report other underlying OS errors. @@ -302,6 +316,24 @@ namespace butl static void current (basic_path const&); + // Return the temporary directory. Throw std::system_error to report the + // underlying OS errors. + // + static dir_type + temp_directory () {return dir_type (traits::temp_directory ());} + + // Return a temporary path. The path is constructed by starting with the + // temporary directory and then appending a path component consisting of + // the prefix followed by the process id following by a unique counter + // value inside the process. Throw std::system_error to report the + // underlying OS errors. + // + static basic_path + temp_path (const string_type& prefix) + { + return temp_directory () / basic_path (traits::temp_name (prefix)); + } + public: bool empty () const diff --git a/butl/path.cxx b/butl/path.cxx index 3e82190..1f8f195 100644 --- a/butl/path.cxx +++ b/butl/path.cxx @@ -5,18 +5,29 @@ #include #ifdef _WIN32 -# include // _MAX_PATH -# include // _[w]getcwd(), _[w]chdir() +# include // _MAX_PATH +# include // _[w]getcwd(), _[w]chdir() +# ifndef WIN32_LEAN_AND_MEAN +# define WIN32_LEAN_AND_MEAN +# endif +# include // GetTempPath*() +# include // unique_ptr #else -# include // EINVAL -# include // mbstowcs(), wcstombs(), realpath() -# include // PATH_MAX -# include // getcwd(), chdir() +# include // EINVAL +# include // mbstowcs(), wcstombs(), realpath(), getenv() +# include // PATH_MAX +# include // getcwd(), chdir() +# include // strlen(), strcpy() +# include // stat(), S_IS* +# include // stat #endif +#include #include #include +#include + #ifndef _WIN32 # ifndef PATH_MAX # define PATH_MAX 4096 @@ -69,6 +80,88 @@ namespace butl #endif } +#ifdef _WIN32 + struct msg_deleter + { + void operator() (char* p) const {LocalFree (p);} + }; + + static string + last_error () + { + DWORD e (GetLastError ()); + char* msg; + if (!FormatMessageA ( + FORMAT_MESSAGE_ALLOCATE_BUFFER | + FORMAT_MESSAGE_FROM_SYSTEM | + FORMAT_MESSAGE_IGNORE_INSERTS | + FORMAT_MESSAGE_MAX_WIDTH_MASK, + 0, + e, + MAKELANGID (LANG_NEUTRAL, SUBLANG_DEFAULT), + (char*)&msg, + 0, + 0)) + return "unknown error code " + to_string (e); + + unique_ptr m (msg); + return msg; + } +#else + static const char* + temp_directory () + { + const char* dir (nullptr); + const char* env[] = {"TMPDIR", "TMP", "TEMP", "TEMPDIR", nullptr}; + + for (auto e (env); dir == nullptr && *e != nullptr; ++e) + dir = getenv (*e); + + if (dir == nullptr) + dir = "/tmp"; + + struct stat s; + if (stat (dir, &s) != 0) + throw system_error (errno, system_category ()); + + if (!S_ISDIR (s.st_mode)) + throw system_error (ENOTDIR, system_category ()); + + return dir; + } +#endif + + template <> + path_traits::string_type path_traits:: + temp_directory () + { +#ifdef _WIN32 + char d[_MAX_PATH + 1]; + DWORD r (GetTempPathA (_MAX_PATH + 1, d)); + + if (r == 0) + { + string e (last_error ()); + throw system_error (ENOTDIR, system_category (), e); + } + + return string_type (d); +#else + return string_type (butl::temp_directory ()); +#endif + } + + static atomic temp_name_count; + + template <> + path_traits::string_type path_traits:: + temp_name (string_type const& prefix) + { + return prefix + + "-" + to_string (process::current_id ()) + + "-" + to_string (temp_name_count++); + } + #ifndef _WIN32 template <> void path_traits:: @@ -135,6 +228,48 @@ namespace butl #endif } + template <> + path_traits::string_type path_traits:: + temp_directory () + { +#ifdef _WIN32 + wchar_t d[_MAX_PATH + 1]; + DWORD r (GetTempPathW (_MAX_PATH + 1, d)); + + if (r == 0) + { + string e (last_error ()); + throw system_error (ENOTDIR, system_category (), e); + } +#else + wchar_t d[PATH_MAX]; + + // The usage of mbstowcs() supposes the program's C-locale is set to the + // proper locale before the call (can be done with setlocale(LC_ALL, "...") + // call). Otherwise mbstowcs() fails with EILSEQ errno for non-ASCII + // directory paths. + // + size_t r (mbstowcs (d, butl::temp_directory (), PATH_MAX)); + + if (r == size_t (-1)) + throw system_error (EINVAL, system_category ()); + + if (r == PATH_MAX) + throw system_error (ENOTSUP, system_category ()); +#endif + + return string_type (d); + } + + template <> + path_traits::string_type path_traits:: + temp_name (string_type const& prefix) + { + return prefix + + L"-" + to_wstring (process::current_id ()) + + L"-" + to_wstring (temp_name_count++); + } + #ifndef _WIN32 template <> void path_traits:: -- cgit v1.1