compat: add portable setenv(3)

2 files changed, 50 insertions, 0 deletions

diff --git a/compat/setenv.cpp b/compat/setenv.cpp
new file mode 100644
index 00000000..cb98fa3d
--- /dev/null
+++ b/compat/setenv.cpp
@@ -0,0 +1,37 @@
+#include "setenv.hpp"
+#include <cerrno>
+#include <cstdlib>
+#include <cstring>
+#include <Corrade/Containers/String.h>
+#include <Corrade/Containers/StringIterable.h>
+
+namespace floormat {
+
+#ifdef _WIN32
+int setenv(const char* name, const char* value, int overwrite)
+{
+    if (!std::strchr(name, '=') || !value || !*value)
+    {
+        errno = EINVAL;
+        return -1;
+    }
+    if (!overwrite)
+        if (const auto* s = std::getenv(name); s && *s)
+            return 0;
+
+    return _putenv("="_s.join(StringIterable{name, value}).data());
+}
+
+int unsetenv(const char* name)
+{
+    if (!name || !*name)
+    {
+        errno = EINVAL;
+        return -1;
+    }
+
+    return _putenv("="_s.join(StringIterable{name, ""_s}).data());
+}
+#endif
+
+} // namespace floormat
diff --git a/compat/setenv.hpp b/compat/setenv.hpp
new file mode 100644
index 00000000..5dff666a
--- /dev/null
+++ b/compat/setenv.hpp
@@ -0,0 +1,13 @@
+#pragma once
+#include <cstdlib>
+
+#ifdef _WIN32
+namespace floormat {
+using std::getenv;
+int setenv(const char* name, const char* value, int overwrite);
+int unsetenv(const char* name);
+} // namespace floormat
+#else
+#include <cstdlib>
+namespace floormat { using std::getenv; using std::setenv; using std::unsetenv; }
+#endif