From f804a61c1c58529e7c98555a921b56bc05059d5e Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Mon, 30 Aug 2021 02:15:57 +0300
Subject: [PATCH] Add wrappers for environment manipulation functions

---
 source/core/environ.h           | 14 +++++++++++
 source/core/unix/environ.cpp    | 34 ++++++++++++++++++++++++++
 source/core/windows/environ.cpp | 42 +++++++++++++++++++++++++++++++++
 source/fs/dir.cpp               | 10 ++++----
 source/fs/osx/dir_location.cpp  |  5 ++--
 source/fs/unix/dir_location.cpp |  6 ++---
 6 files changed, 102 insertions(+), 9 deletions(-)
 create mode 100644 source/core/environ.h
 create mode 100644 source/core/unix/environ.cpp
 create mode 100644 source/core/windows/environ.cpp

diff --git a/source/core/environ.h b/source/core/environ.h
new file mode 100644
index 0000000..67fde05
--- /dev/null
+++ b/source/core/environ.h
@@ -0,0 +1,14 @@
+#ifndef ENVIRON_H_
+#define ENVIRON_H_
+
+#include <string>
+
+namespace Msp {
+
+std::string getenv(const std::string &);
+void setenv(const std::string &, const std::string &);
+void unsetenv(const std::string &);
+
+} // namespace Msp
+
+#endif
diff --git a/source/core/unix/environ.cpp b/source/core/unix/environ.cpp
new file mode 100644
index 0000000..037a0e9
--- /dev/null
+++ b/source/core/unix/environ.cpp
@@ -0,0 +1,34 @@
+#include <cstdlib>
+#include "environ.h"
+#include "mutex.h"
+
+using namespace std;
+
+namespace Msp {
+
+static Mutex &env_mutex()
+{
+	static Mutex mutex;
+	return mutex;
+}
+
+string getenv(const string &name)
+{
+	MutexLock _lock(env_mutex());
+	const char *value = std::getenv(name.c_str());
+	return (value ? string(value) : string());
+}
+
+void setenv(const string &name, const string &value)
+{
+	MutexLock _lock(env_mutex());
+	::setenv(name.c_str(), value.c_str(), true);
+}
+
+void unsetenv(const string &name)
+{
+	MutexLock _lock(env_mutex());
+	::unsetenv(name.c_str());
+}
+
+}
diff --git a/source/core/windows/environ.cpp b/source/core/windows/environ.cpp
new file mode 100644
index 0000000..ff5c2b0
--- /dev/null
+++ b/source/core/windows/environ.cpp
@@ -0,0 +1,42 @@
+#include <stdlib.h>
+#include "environ.h"
+#include "mutex.h"
+
+#ifdef __GNUC__
+extern "C" errno_t getenv_s(size_t *, char *, size_t, const char *);
+#endif
+
+using namespace std;
+
+namespace Msp {
+
+static Mutex &env_mutex()
+{
+	static Mutex mutex;
+	return mutex;
+}
+
+string getenv(const string &name)
+{
+	MutexLock _lock(env_mutex());
+	char buffer[1024];
+	size_t result;
+	if(!getenv_s(&result, buffer, sizeof(buffer), name.c_str()))
+		return buffer;
+	else
+		return string();
+}
+
+void setenv(const string &name, const string &value)
+{
+	MutexLock _lock(env_mutex());
+	_putenv_s(name.c_str(), value.c_str());
+}
+
+void unsetenv(const string &name)
+{
+	MutexLock _lock(env_mutex());
+	_putenv_s(name.c_str(), "");
+}
+
+}
diff --git a/source/fs/dir.cpp b/source/fs/dir.cpp
index 0980203..218a7a5 100644
--- a/source/fs/dir.cpp
+++ b/source/fs/dir.cpp
@@ -1,7 +1,6 @@
-#include <cstdlib>
-#include <unistd.h>
 #include <dirent.h>
 #include <msp/core/application.h>
+#include <msp/core/environ.h>
 #include <msp/core/systemerror.h>
 #include <msp/strings/regex.h>
 #include <msp/strings/utils.h>
@@ -38,7 +37,9 @@ const Path &get_bin_dir(const string &argv0)
 	{
 		Path exe;
 		if(argv0.find(DIRSEP)==string::npos)
-			if(const char *path = getenv("PATH"))
+		{
+			string path = getenv("PATH");
+			if(!path.empty())
 			{
 				for(const string &d: split(path, ITEMSEP))
 					if(exists(Path(d)/argv0))
@@ -47,6 +48,7 @@ const Path &get_bin_dir(const string &argv0)
 						break;
 					}
 			}
+		}
 
 		if(exe.empty())
 			exe = realpath(argv0);
@@ -191,7 +193,7 @@ Path path_lookup(const string &name, const vector<Path> &paths)
 
 Path path_lookup(const string &name)
 {
-	const char *path = getenv("PATH");
+	string path = getenv("PATH");
 	vector<string> dirs = split(path, ITEMSEP);
 	return path_lookup(name, vector<Path>(dirs.begin(), dirs.end()));
 }
diff --git a/source/fs/osx/dir_location.cpp b/source/fs/osx/dir_location.cpp
index 89d6f57..b58b971 100644
--- a/source/fs/osx/dir_location.cpp
+++ b/source/fs/osx/dir_location.cpp
@@ -1,4 +1,5 @@
 #include <msp/core/application.h>
+#include <msp/core/environ.h>
 #include "dir.h"
 
 using namespace std;
@@ -16,8 +17,8 @@ Path get_home_dir()
 	if(len)
 		return string(buf, len);
 
-	const char *home = getenv("HOME");
-	if(home)
+	string home = getenv("HOME");
+	if(!home.empty())
 		return home;
 
 	return ".";
diff --git a/source/fs/unix/dir_location.cpp b/source/fs/unix/dir_location.cpp
index c980bb2..7382587 100644
--- a/source/fs/unix/dir_location.cpp
+++ b/source/fs/unix/dir_location.cpp
@@ -1,5 +1,5 @@
-#include <cstdlib>
 #include <msp/core/application.h>
+#include <msp/core/environ.h>
 #include "dir.h"
 
 using namespace std;
@@ -9,8 +9,8 @@ namespace FS {
 
 Path get_home_dir()
 {
-	const char *home = getenv("HOME");
-	if(home)
+	string home = getenv("HOME");
+	if(!home.empty())
 		return home;
 	return ".";
 }
-- 
2.43.0