5 files changed, 88 insertions, 4 deletions

diff --git a/nihil.posix/CMakeLists.txt b/nihil.posix/CMakeLists.txt
index d76ae4d..25f13f1 100644
--- a/nihil.posix/CMakeLists.txt
+++ b/nihil.posix/CMakeLists.txt
@@ -30,6 +30,7 @@ target_sources(nihil.posix
 	open_in_path.ccm
 	paths.ccm
 	process.ccm
+	progname.ccm
 	read_file.ccm
 	rename.ccm
 	spawn.ccm
diff --git a/nihil.posix/execv.ccm b/nihil.posix/execv.ccm
index d598d94..cd501f7 100644
--- a/nihil.posix/execv.ccm
+++ b/nihil.posix/execv.ccm
@@ -3,6 +3,10 @@ module;
 
 #include <unistd.h> // execv()
 
+#include "nihil.hh"
+
+extern char **environ; // NOLINT
+
 export module nihil.posix:execv;
 
 import nihil.std;
@@ -56,7 +60,7 @@ export struct execv final
 
 			[&] (fd const &file) {
 #if NIHIL_HAVE_FEXECVE == 1
-				::fexecv(file.get(), self.m_args.data());
+				::fexecve(file.get(), self.m_args.data(), environ);
 				return std::unexpected(error("execve failed", error(sys_error())));
 #else
 				std::ignore = file;
diff --git a/nihil.posix/open.ccm b/nihil.posix/open.ccm
index f2f5ecd..a5a9e5d 100644
--- a/nihil.posix/open.ccm
+++ b/nihil.posix/open.ccm
@@ -39,9 +39,6 @@ export inline constexpr auto open_shared_lock = open_flags::mask<O_SHLOCK>();
 export inline constexpr auto open_exclusive_lock = open_flags::mask<O_EXLOCK>();
 export inline constexpr auto open_directory = open_flags::mask<O_DIRECTORY>();
 export inline constexpr auto open_nofollow = open_flags::mask<O_NOFOLLOW>();
-export inline constexpr auto open_nofollow_any = open_flags::mask<O_NOFOLLOW_ANY>();
-export inline constexpr auto open_symlink = open_flags::mask<O_SYMLINK>();
-export inline constexpr auto open_eventonly = open_flags::mask<O_EVTONLY>();
 export inline constexpr auto open_close_on_exec = open_flags::mask<O_CLOEXEC>();
 export inline constexpr auto open_resolve_beneath = open_flags::mask<O_RESOLVE_BENEATH>();
 
@@ -62,6 +59,19 @@ export inline constexpr auto open_path = open_flags::mask<O_PATH>();
 export inline constexpr auto open_empty_path = open_flags::mask<O_EMPTY_PATH>();
 #endif
 
+// macOS
+#ifdef O_NOFOLLOW_ANY
+export inline constexpr auto open_nofollow_any = open_flags::mask<O_NOFOLLOW_ANY>();
+#endif
+
+#ifdef O_SYMLINK
+export inline constexpr auto open_symlink = open_flags::mask<O_SYMLINK>();
+#endif
+
+#ifdef O_EVTONLY
+export inline constexpr auto open_eventonly = open_flags::mask<O_EVTONLY>();
+#endif
+
 // Open the given file and return an fd for it.
 export [[nodiscard]] auto open(std::filesystem::path const &filename, open_flags flags,
                                int mode = 0777) -> std::expected<fd, error>
diff --git a/nihil.posix/posix.ccm b/nihil.posix/posix.ccm
index aa21649..c80724d 100644
--- a/nihil.posix/posix.ccm
+++ b/nihil.posix/posix.ccm
@@ -19,6 +19,7 @@ export import :open;
 export import :open_in_path;
 export import :paths;
 export import :process;
+export import :progname;
 export import :read_file;
 export import :rename;
 export import :spawn;
diff --git a/nihil.posix/progname.ccm b/nihil.posix/progname.ccm
new file mode 100644
index 0000000..127b972
--- /dev/null
+++ b/nihil.posix/progname.ccm
@@ -0,0 +1,68 @@
+// This source code is released into the public domain.
+module;
+
+// progname: wrappers for getprogname and setprogname.
+//
+// setprogname() doesn't copy the provided name, which makes it awkward to provide
+// dynamic values (e.g., std::string).  We solve this by making setprogname a guard
+// object which resets the previous progname when it's destroyed.  This also happens
+// to be useful in cases like nihil.cli where we want to temporarily set the progname.
+
+#include <stdlib.h> // NOLINT
+
+export module nihil.posix:progname;
+
+import nihil.std;
+
+namespace nihil {
+
+// Get the current program name.  We could return std::string_view here, but since
+// the current program name can change unexpectedly, we don't.
+export [[nodiscard]] auto getprogname() -> std::optional<std::string>
+{
+	if (auto const *progname = ::getprogname(); progname != nullptr)
+		return {progname};
+	return {};
+}
+
+// Set the progname name to a new value for the lifetime of this object.
+// Reset it to the previous value when the object is destroyed.
+export struct setprogname final
+{
+	// Set the program name.
+	explicit setprogname(std::string_view const progname)
+		: m_progname(progname)
+		, m_old_progname(::getprogname())
+	{
+		::setprogname(m_progname.data());
+	}
+
+	// Restore the old name on destruction.
+	~setprogname()
+	{
+		if (m_old_progname != nullptr)
+			::setprogname(m_old_progname);
+	}
+
+	// Restore the old program name immediately.
+	auto release() -> void
+	{
+		if (m_old_progname != nullptr) {
+			::setprogname(m_old_progname);
+			m_old_progname = nullptr;
+		}
+	}
+
+	// Not copyable.
+	setprogname(setprogname const &) = delete;
+	auto operator=(setprogname const &) -> setprogname & = delete;
+
+	// Not movable.
+	setprogname(setprogname &&) = delete;
+	auto operator=(setprogname &&) -> setprogname & = delete;
+
+private:
+	std::string m_progname;
+	char const *m_old_progname;
+};
+} // namespace nihil