Generic environment set/clear functions, file function to get app exe path

src/pya/pya/pya.cc

@@ -40,10 +40,6 @@
 #include "tlString.h"
 #include "tlInternational.h"
 
-#if defined(HAVE_QT)
-#  include <QCoreApplication>
-#endif
-
 //  For the installation path
 #ifdef _WIN32
 #  include <windows.h>
@@ -225,10 +221,7 @@ PythonInterpreter::PythonInterpreter (bool embedded)
 
   tl::SelfTimer timer (tl::verbosity () >= 21, "Initializing Python");
 
-  std::string app_path;
-#if defined(HAVE_QT)
-  app_path = tl::to_string (QCoreApplication::applicationFilePath ());
-#endif
+  std::string app_path = tl::get_exe_file ();
 
 #if PY_MAJOR_VERSION >= 3
 

src/tl/tl/tlEnv.cc

@@ -58,6 +58,28 @@ std::string get_env (const std::string &name, const std::string &def_value)
 #endif
 }
 
+void set_env (const std::string &name, const std::string &value)
+{
+#ifdef _WIN32
+  std::wstring wstr = tl::to_wstring (name + "=" + value);
+  _wputenv (wstr.c_str ());
+#else
+  char *str = strdup ((name + "=" + value).c_str ());
+  putenv (str);
+#endif
+}
+
+void unset_env (const std::string &name)
+{
+#ifdef _WIN32
+  std::wstring wstr = tl::to_wstring (name + "=");
+  _wputenv (wstr.c_str ());
+#else
+  char *str = strdup (name.c_str ());  //  TODO: needed?
+  putenv (str);
+#endif
+}
+
 bool has_env (const std::string &name)
 {
 #ifdef _WIN32

src/tl/tl/tlEnv.h

@@ -38,6 +38,18 @@ namespace tl
  */
 std::string TL_PUBLIC get_env (const std::string &name, const std::string &def_value = std::string ());
 
+/**
+ *  @brief Sets the value of the given environment variable
+ *
+ *  On Windows, the variable is removed when the value is an empty string.
+ */
+void TL_PUBLIC set_env (const std::string &name, const std::string &value);
+
+/**
+ *  @brief Unsets the given environment variable
+ */
+void TL_PUBLIC unset_env (const std::string &name);
+
 /**
  *  @brief Gets the value if the given environment variable is set
  */

src/tl/tl/tlFileUtils.cc

@@ -862,7 +862,7 @@ get_inst_path_internal ()
   wchar_t buffer[MAX_PATH];
   int len;
   if ((len = GetModuleFileNameW (NULL, buffer, MAX_PATH)) > 0) {
-    return tl::absolute_path (tl::to_string (std::wstring (buffer)));
+    return tl::to_string (std::wstring (buffer));
   }
 
 #elif __APPLE__
@@ -871,7 +871,7 @@ get_inst_path_internal ()
   int ret = proc_pidpath (getpid (), buffer, sizeof (buffer));
   if (ret > 0) {
     //  TODO: does this correctly translate paths? (MacOS uses UTF-8 encoding with D-like normalization)
-    return tl::absolute_path (buffer);
+    return std::string (buffer);
   }
 
 #elif defined (__FreeBSD__)
@@ -880,7 +880,7 @@ get_inst_path_internal ()
   size_t len = PATH_MAX;
   const int mib[4] = {CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1};
   if (sysctl(&mib[0], 4, &path, &len, NULL, 0) == 0) {
-    return tl::absolute_path(path);
+    return path;
   }
   return "";
 
@@ -888,7 +888,7 @@ get_inst_path_internal ()
 
   std::string pf = tl::sprintf ("/proc/%d/exe", getpid ());
   if (tl::file_exists (pf)) {
-    return tl::absolute_path (pf);
+    return pf;
   }
 
 #endif
@@ -900,7 +900,17 @@ get_inst_path ()
 {
   static std::string s_inst_path;
   if (s_inst_path.empty ()) {
-    s_inst_path = get_inst_path_internal ();
+    s_inst_path = tl::absolute_path (get_inst_path_internal ());
+  }
+  return s_inst_path;
+}
+
+std::string
+get_exe_file ()
+{
+  static std::string s_inst_path;
+  if (s_inst_path.empty ()) {
+    s_inst_path = tl::absolute_file_path (get_inst_path_internal ());
   }
   return s_inst_path;
 }

src/tl/tl/tlFileUtils.h

@@ -199,6 +199,11 @@ std::vector<std::string> TL_PUBLIC split_path (const std::string &p, bool keep_l
  */
 std::string TL_PUBLIC get_inst_path ();
 
+/**
+ *  @brief Gets the path of the binary executing
+ */
+std::string TL_PUBLIC get_exe_file ();
+
 /**
  *  @brief Gets the absolute path of the module (DLL/.so) which contains the given address
  *  "address" is supposed to be the address of a function inside the module.

src/tl/unit_tests/tlEnvTests.cpp

@@ -0,0 +1,44 @@
+
+/*
+
+  KLayout Layout Viewer
+  Copyright (C) 2006-2023 Matthias Koefferlein
+
+  This program is free software; you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation; either version 2 of the License, or
+  (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program; if not, write to the Free Software
+  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+
+*/
+
+
+#include "tlEnv.h"
+#include "tlUnitTest.h"
+
+TEST(1)
+{
+  const char *env_name = "$$$DOESNOTEXIST";
+
+  EXPECT_EQ (tl::has_env (env_name), false);
+  EXPECT_EQ (tl::has_env ("HOME"), true);
+
+  tl::set_env (env_name, "abc");
+  EXPECT_EQ (tl::has_env (env_name), true);
+  EXPECT_EQ (tl::get_env (env_name), "abc");
+
+  tl::set_env (env_name, "uvw");
+  EXPECT_EQ (tl::has_env (env_name), true);
+  EXPECT_EQ (tl::get_env (env_name), "uvw");
+
+  tl::unset_env (env_name);
+  EXPECT_EQ (tl::has_env (env_name), false);
+}

src/tl/unit_tests/unit_tests.pro

@@ -16,6 +16,7 @@ SOURCES = \
   tlDataMappingTests.cc \
   tlDeferredExecutionTests.cc \
   tlDeflateTests.cc \
+  tlEnvTests.cpp \
   tlEventsTests.cc \
   tlExpressionTests.cc \
   tlFileSystemWatcherTests.cc \