diff options
| -rw-r--r-- | libbutl/process.cxx | 102 | ||||
| -rw-r--r-- | libbutl/process.hxx | 3 | ||||
| -rw-r--r-- | tests/process/driver.cxx | 11 |
3 files changed, 91 insertions, 25 deletions
diff --git a/libbutl/process.cxx b/libbutl/process.cxx index 6f4fd30..ed01ca1 100644 --- a/libbutl/process.cxx +++ b/libbutl/process.cxx @@ -23,10 +23,12 @@ # pragma warning (pop) # endif -# include <io.h> // _get_osfhandle(), _close() -# include <stdlib.h> // _MAX_PATH -# include <sys/types.h> // stat -# include <sys/stat.h> // stat(), S_IS* +# include <io.h> // _get_osfhandle(), _close() +# include <stdlib.h> // _MAX_PATH +# include <sys/types.h> // stat +# include <sys/stat.h> // stat(), S_IS* +# include <processenv.h> // GetEnvironmentStringsA(), + // FreeEnvironmentStringsA() # ifdef _MSC_VER // Unlikely to be fixed in newer versions. # define S_ISREG(m) (((m) & S_IFMT) == S_IFREG) @@ -47,7 +49,7 @@ #include <ios> // ios_base::failure #include <cassert> #include <cstddef> // size_t -#include <cstring> // strlen(), strchr() +#include <cstring> // strlen(), strchr(), strncmp() #include <utility> // move() #include <ostream> @@ -944,10 +946,87 @@ namespace butl const char* cwd, const char* const* envvars) { - // Currently we don't support (un)setting environment variables for the - // child process. + auto fail = [] (const char* m = nullptr) + { + throw process_error (m == nullptr ? last_error_msg () : m); + }; + + // (Un)set the environment variables for the child process. + // + // Note that we can not do it incrementally, as for POSIX implementation. + // Instead we need to create the full environment block and pass it to the + // CreateProcess() function call. So we will copy variables from the + // environment block of the current process, but only those that are not + // requested to be (un)set. After that we will additionally copy variables + // that need to be set. // - assert (envvars == nullptr); + vector<char> new_env; + + if (envvars != nullptr) + { + // The environment block contains the variables in the following format: + // + // name=value\0...\0 + // + // Note the trailing NULL character that follows the last variable + // (null-terminated) string. + // + unique_ptr<char, void (*)(char*)> cvars ( + GetEnvironmentStringsA (), + [] (char* p) + { + // We should be able to successfully free the valid environment + // variables memory block, unless something is severely damaged. + // + if (p != nullptr && !FreeEnvironmentStringsA (p)) + assert (false); + }); + + if (cvars.get () == nullptr) + fail (); + + const char* cv (cvars.get ()); + + // Copy the current environment variables. + // + while (*cv != '\0') + { + // Lookup the existing variable among those that are requested to be + // (un)set. If not present, than copy it to the new block. + // + // Note that we don't expect the number of variables to (un)set to be + // large, so the linear search is OK. + // + size_t n (strlen (cv) + 1); // Includes NULL character. + + const char* eq (strchr (cv, '=')); + size_t nn (eq != nullptr ? eq - cv : n - 1); + const char* const* ev (envvars); + + for (; *ev != nullptr; ++ev) + { + const char* v (*ev); + if (strncmp (cv, v, nn) == 0 && (v[nn] == '=' || v[nn] == '\0')) + break; + } + + if (*ev == nullptr) + new_env.insert (new_env.end (), cv, cv + n); + + cv += n; + } + + // Copy the environment variables that are requested to be set. + // + for (const char* const* ev (envvars); *ev != nullptr; ++ev) + { + const char* v (*ev); + if (strchr (v, '=') != nullptr) + new_env.insert (new_env.end (), v, v + strlen (v) + 1); + } + + new_env.push_back ('\0'); // Terminate the new environment block. + } // Figure out if this is a batch file since running them requires starting // cmd.exe and passing the batch file as an argument (see CreateProcess() @@ -991,11 +1070,6 @@ namespace butl } }; - auto fail = [](const char* m = nullptr) - { - throw process_error (m == nullptr ? last_error_msg () : m); - }; - auto open_null = [] () -> auto_fd { // Note that we are using a faster, temporary file-based emulation of @@ -1315,7 +1389,7 @@ namespace butl 0, // Primary thread security attributes. true, // Inherit handles. 0, // Creation flags. - 0, // Use our environment. + envvars != nullptr ? new_env.data () : nullptr, cwd != nullptr && *cwd != '\0' ? cwd : nullptr, &si, &pi)) diff --git a/libbutl/process.hxx b/libbutl/process.hxx index ca49369..ee17207 100644 --- a/libbutl/process.hxx +++ b/libbutl/process.hxx @@ -222,8 +222,7 @@ namespace butl // the child process. If not NULL, it must contain strings in the // "name=value" (set) or "name" (unset) forms and be terminated with // NULL. Note that all other variables are inherited from the parent - // process. Also note that currently is not supported on Windows so must be - // NULL. + // process. // // Throw process_error if anything goes wrong. Note that some of the // exceptions (e.g., if exec() failed) can be thrown in the child diff --git a/tests/process/driver.cxx b/tests/process/driver.cxx index 8e0ad36..0338af2 100644 --- a/tests/process/driver.cxx +++ b/tests/process/driver.cxx @@ -51,14 +51,12 @@ exec (const path& p, // sure that the child process will not see the variable that is requested // to be unset, and will see the other one unaffected. // - // Note that we don't support (un)setting environment variables for the - // child process on Windows. - // #ifndef _WIN32 assert (setenv ("DEF", "2", 1) == 0); assert (setenv ("XYZ", "3", 1) == 0); #else - assert (false); + assert (_putenv ("DEF=2") == 0); + assert (_putenv ("XYZ=3") == 0); #endif } @@ -328,12 +326,7 @@ main (int argc, const char* argv[]) // Passing environment variables to the child process. // - // Note that we don't support (un)setting environment variables for the - // child process on Windows. - // -#ifndef _WIN32 assert (exec (p, string (), false, false, false, dir_path (), true)); -#endif // Transmit large binary data through the child. // |