Make a portable hook for getting program name.

System/programName.h

@@ -0,0 +1,46 @@
+static_assert( __cplusplus > 2020'99 );
+
+#pragma once
+
+#include <Alepha/Alepha.h>
+
+#if   defined( __FreeBSD__ )
+#	include <sys/types.h>
+#	include <sys/sysctl.h>
+#elif defined( _GNU_SOURCE )
+#endif
+
+#include <string>
+
+namespace Alepha::Hydrogen::System  ::detail::  programName_m
+{
+	inline namespace exports
+	{
+		inline std::string
+		programName()
+		{
+			#if   defined( __FreeBSD__ )
+			int mib[]
+			{
+				CTL_KERN,
+				KERN_PROC,
+				KERN_PROC_PATHNAME,
+				-1,
+			};
+			char buf[ 4096 ];
+			std::size_t cb = sizeof( buf );
+			::sysctl( mib, 4, buf, &cb, nullptr, 0);
+			return buf;
+			#elif defined( _GNU_SOURCE )
+			return ::program_invocation_short_name;
+			#else
+			#error "Not supported."
+			#endif
+		}
+	}
+}
+
+namespace Alepha::Hydrogen::System::inline exports::inline programName_m
+{
+	using namespace detail::programName_m::exports;
+}