Add support for specifying child process cwd and env to wxExecute().

Add an optional wxExecuteEnv parameter to wxExecute() which allows to specify
the initial working directory and custom environment for the child process.

Closes #12163.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@65896 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/unix/utilsunx.cpp

@@ -442,27 +442,30 @@ private:
 bool wxMacLaunch(char **argv);
 #endif
 
-long wxExecute(const wxString& command, int flags, wxProcess *process)
+long wxExecute(const wxString& command, int flags, wxProcess *process,
+        const wxExecuteEnv *env)
 {
     ArgsArray argv(wxCmdLineParser::ConvertStringToArgs(command,
                                                         wxCMD_LINE_SPLIT_UNIX));
 
-    return wxExecute(argv, flags, process);
+    return wxExecute(argv, flags, process, env);
 }
 
 #if wxUSE_UNICODE
 
-long wxExecute(wchar_t **wargv, int flags, wxProcess *process)
+long wxExecute(wchar_t **wargv, int flags, wxProcess *process,
+        const wxExecuteEnv *env)
 {
     ArgsArray argv(wargv);
 
-    return wxExecute(argv, flags, process);
+    return wxExecute(argv, flags, process, env);
 }
 
 #endif // wxUSE_UNICODE
 
 // wxExecute: the real worker function
-long wxExecute(char **argv, int flags, wxProcess *process)
+long wxExecute(char **argv, int flags, wxProcess *process,
+        const wxExecuteEnv *env)
 {
     // for the sync execution, we return -1 to indicate failure, but for async
     // case we return 0 which is never a valid PID
@@ -577,6 +580,40 @@ long wxExecute(char **argv, int flags, wxProcess *process)
             pipeErr.Close();
         }
 
+        // Process additional options if we have any
+        if ( env )
+        {
+            // Change working directory if it is specified
+            if ( !env->cwd.empty() )
+                wxSetWorkingDirectory(env->cwd);
+
+            // Change environment if needed.
+            //
+            // NB: We can't use execve() currently because we allow using
+            //     non full paths to wxExecute(), i.e. we want to search for
+            //     the program in PATH. However it just might be simpler/better
+            //     to do the search manually and use execve() envp parameter to
+            //     set up the environment of the child process explicitly
+            //     instead of doing what we do below.
+            if ( !env->env.empty() )
+            {
+                wxEnvVariableHashMap oldenv;
+                wxGetEnvMap(&oldenv);
+
+                // Remove unwanted variables
+                wxEnvVariableHashMap::const_iterator it;
+                for ( it = oldenv.begin(); it != oldenv.end(); ++it )
+                {
+                    if ( env->env.find(it->first) == env->env.end() )
+                        wxUnsetEnv(it->first);
+                }
+
+                // And add the new ones (possibly replacing the old values)
+                for ( it = env->env.begin(); it != env->env.end(); ++it )
+                    wxSetEnv(it->first, it->second);
+            }
+        }
+
         execvp(*argv, argv);
 
         fprintf(stderr, "execvp(");