Rewrite in Rust

.gitignore

@@ -1,3 +1 @@
-*.o
-
-/polytree-session
+/target/

Cargo.lock

@@ -0,0 +1,16 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "libc"
+version = "0.2.107"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fbe5e23404da5b4f555ef85ebed98fb4083e55a00c317800bc2a50ede9f3d219"
+
+[[package]]
+name = "polytree-session"
+version = "0.0.0"
+dependencies = [
+ "libc",
+]

Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "polytree-session"
+version = "0.0.0"
+authors = ["Alex Kotov <kotovalexarian@gmail.com>"]
+edition = "2021"
+description = "Polytree session manager"
+readme = true
+homepage = "https://github.com/PolytreeWM/polytree-session"
+repository = "https://github.com/PolytreeWM/polytree-session.git"
+license = "MIT"
+keywords = ["gui"]
+categories = ["gui"]
+publish = true
+
+[dependencies]
+libc = "0.2.107"

Makefile

@@ -1,33 +1,17 @@
 # Polytree Session - session manager
 
+all: target/debug/polytree-session
+
 include config.mk
 
-SRC = status.c main.c
-HDR = status.h
-OBJ = $(SRC:.c=.o)
+SRC = Cargo.toml src/main.rs
 
-all: options polytree-session
-
-options:
-	@echo Polytree Session build options:
-	@echo "CFLAGS  = $(CFLAGS)"
-	@echo "LDFLAGS = $(LDFLAGS)"
-	@echo "CC      = $(CC)"
-
-%.o: %.c
-	$(CC) -c $< -o $@ $(CFLAGS)
-
-OBJ: config.mk $(HDR)
-
-polytree-session: $(OBJ)
-	$(CC) -o $@ $(OBJ) $(LDFLAGS)
-
-clean:
-	rm -f polytree-session $(OBJ)
+target/debug/polytree-session: $(SRC)
+	cargo build
 
 install: all
 	mkdir -p $(DESTDIR)$(PREFIX)/bin
-	cp -f polytree-session $(DESTDIR)$(PREFIX)/bin
+	cp -f target/debug/polytree-session $(DESTDIR)$(PREFIX)/bin
 	chmod 755 $(DESTDIR)$(PREFIX)/bin/polytree-session
 
 xinstall: install
@@ -45,4 +29,4 @@ uninstall:
 		$(DESTDIR)$(ICONSPREFIX)/polytree.png \
 		$(DESTDIR)$(XSESSIONSPREFIX)/polytree.desktop
 
-.PHONY: all options clean install xinstall uninstall
+.PHONY: all install xinstall uninstall

config.mk

@@ -6,18 +6,3 @@ SYSPREFIX = /usr
 
 ICONSPREFIX = $(SYSPREFIX)/share/icons
 XSESSIONSPREFIX = $(SYSPREFIX)/share/xsessions
-
-X11INC = /usr/X11R6/include
-X11LIB = /usr/X11R6/lib
-# FreeBSD (uncomment)
-#X11INC = /usr/local/include
-#X11LIB = /usr/local/lib
-
-INCS = -I${X11INC}
-LIBS = -L${X11LIB} -lX11 -lpthread
-
-CPPFLAGS = -D_DEFAULT_SOURCE -D_BSD_SOURCE -D_POSIX_C_SOURCE=200809L -DVERSION=\"$(VERSION)\"
-CFLAGS = -std=c99 -pedantic -Wall -Wextra -Os $(INCS) $(CPPFLAGS)
-LDFLAGS = $(LIBS)
-
-CC = cc

main.c

@@ -1,35 +0,0 @@
-#include "status.h"
-
-#include <stdbool.h>
-#include <stddef.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <sys/types.h>
-#include <sys/wait.h>
-#include <unistd.h>
-
-int main()
-{
-	const pid_t wm_pid = fork();
-
-	if (wm_pid == -1) {
-		perror("polytree-session: WM fork");
-		exit(EXIT_FAILURE);
-	}
-
-	if (wm_pid == 0) {
-		char *const args[] = { "polytreewm", NULL };
-		execvp(args[0], args);
-		perror("polytree-session: WM exec");
-		exit(EXIT_FAILURE);
-	}
-
-	status_start();
-
-	int wm_status;
-	waitpid(wm_pid, &wm_status, 0);
-
-	status_stop();
-
-	exit(WEXITSTATUS(wm_status));
-}

src/main.rs

@@ -0,0 +1,48 @@
+use std::ffi::CString;
+use std::thread;
+
+fn main() {
+	unsafe { unsafe_main() }
+}
+
+unsafe fn unsafe_main() {
+	let wm_pid = libc::fork();
+
+	if wm_pid == -1 {
+		let msg = CString::new(b"polytree-session: WM fork" as &[u8]).unwrap();
+		libc::perror(msg.as_ptr());
+		libc::exit(libc::EXIT_FAILURE);
+	}
+
+	if wm_pid == 0 {
+		let arg0 = CString::new(b"polytreewm" as &[u8]).unwrap();
+		let args = vec![arg0.as_ptr(), std::ptr::null()];
+		libc::execvp(arg0.as_ptr(), args.as_ptr());
+		let msg = CString::new(b"polytree-session: WM exec" as &[u8]).unwrap();
+		libc::perror(msg.as_ptr());
+		libc::exit(libc::EXIT_FAILURE);
+	}
+
+	let status_thread = thread::spawn(move || {
+		let pid = libc::fork();
+
+		if pid == -1 { return };
+
+		if pid == 0 {
+			let arg0 = CString::new(b"slstatus" as &[u8]).unwrap();
+			let args = vec![arg0.as_ptr(), std::ptr::null()];
+			libc::execvp(arg0.as_ptr(), args.as_ptr());
+			let msg = CString::new(b"polytree-session: slstatus exec" as &[u8])
+				.unwrap();
+			libc::perror(msg.as_ptr());
+			libc::exit(libc::EXIT_FAILURE);
+		}
+	});
+
+	let wm_status: i32 = 0;
+	libc::waitpid(wm_pid, wm_status as *mut i32, 0);
+
+	status_thread.join().unwrap();
+
+	libc::exit(libc::WEXITSTATUS(wm_status));
+}

status.c

@@ -1,44 +0,0 @@
-#include "status.h"
-
-#include <signal.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <sys/types.h>
-#include <sys/wait.h>
-#include <unistd.h>
-
-static bool running = false;
-static pid_t pid = 0;
-
-bool status_start()
-{
-	// TODO: maybe we should assert
-	if (running) return false;
-	running = true;
-
-	pid = fork();
-
-	if (pid == -1) {
-		status_stop();
-		return false;
-	}
-
-	if (pid == 0) {
-		char *const args[] = { "slstatus", NULL };
-		execvp(args[0], args);
-		perror("polytree-session: slstatus exec");
-		exit(EXIT_FAILURE);
-	}
-
-	return true;
-}
-
-void status_stop()
-{
-	// TODO: maybe we should assert
-	if (!running) return;
-	running = false;
-
-	kill(pid, SIGKILL);
-	waitpid(pid, NULL, 0);
-}

status.h

@@ -1,9 +0,0 @@
-#ifndef _STATUS_H
-#define _STATUS_H
-
-#include <stdbool.h>
-
-bool status_start();
-void status_stop();
-
-#endif // _STATUS_H