Ported PlaceholderParser::apply_env_variables() to XS

xs/src/libslic3r/PlaceholderParser.cpp

@@ -2,14 +2,16 @@
 #include <ctime>
 #include <iomanip>
 #include <sstream>
+#include <unistd.h>  // provides **environ
+
+extern char **environ;
 
 namespace Slic3r {
 
 PlaceholderParser::PlaceholderParser()
 {
     this->_single["version"] = SLIC3R_VERSION;
-    // TODO: port these methods to C++, then call them here
-    // this->apply_env_variables();
+    this->apply_env_variables();
     this->update_timestamp();
 }
 
@@ -76,6 +78,21 @@ void PlaceholderParser::apply_config(DynamicPrintConfig &config)
     }
 }
 
+void
+PlaceholderParser::apply_env_variables()
+{
+    for (char** env = environ; *env; env++) {
+        if (strncmp(*env, "SLIC3R_", 7) == 0) {
+            std::stringstream ss(*env);
+            std::string key, value;
+            std::getline(ss, key, '=');
+            ss >> value;
+            
+            this->set(key, value);
+        }
+    }
+}
+
 void
 PlaceholderParser::set(const std::string &key, const std::string &value)
 {

xs/src/libslic3r/PlaceholderParser.hpp

@@ -20,6 +20,7 @@ class PlaceholderParser
     PlaceholderParser();
     void update_timestamp();
     void apply_config(DynamicPrintConfig &config);
+    void apply_env_variables();
     void set(const std::string &key, const std::string &value);
     void set(const std::string &key, int value);
     void set(const std::string &key, const std::vector<std::string> &values);