Implement syslog functionality (closes #

Signed-off-by: AnErrupTion <anerruption@disroot.org>

ly-core/src/LogFile.zig

@@ -3,50 +3,85 @@ const interop = @import("interop.zig");
 
 const LogFile = @This();
 
-path: []const u8,
+maybe_path: ?[]const u8,
 could_open_log_file: bool = undefined,
-file: std.Io.File = undefined,
+maybe_file: ?std.Io.File = null,
 buffer: []u8,
-file_writer: std.Io.File.Writer = undefined,
+maybe_file_writer: ?std.Io.File.Writer = null,
+
+pub fn init(io: std.Io, path: ?[]const u8, buffer: []u8) !LogFile {
+    var log_file = LogFile{
+        .maybe_path = path,
+        .buffer = buffer,
+    };
+
+    if (path) |p| {
+        log_file.could_open_log_file = try openLogFile(io, p, &log_file);
+    } else {
+        std.posix.system.openlog("ly", 0, 0);
+        log_file.could_open_log_file = true;
+    }
 
-pub fn init(io: std.Io, path: []const u8, buffer: []u8) !LogFile {
-    var log_file = LogFile{ .path = path, .buffer = buffer };
-    log_file.could_open_log_file = try openLogFile(io, path, &log_file);
     return log_file;
 }
 
 pub fn reinit(self: *LogFile, io: std.Io) !void {
-    self.could_open_log_file = try openLogFile(io, self.path, self);
+    if (self.maybe_path) |path| {
+        self.could_open_log_file = try openLogFile(io, path, self);
+    } else {
+        std.posix.system.openlog("ly", 0, 0);
+        self.could_open_log_file = true;
+    }
 }
 
 pub fn deinit(self: *LogFile, io: std.Io) void {
-    self.file.close(io);
+    if (self.maybe_file) |file| {
+        file.close(io);
+    } else {
+        std.posix.system.closelog();
+    }
 }
 
 pub fn info(self: *LogFile, io: std.Io, category: []const u8, comptime message: []const u8, args: anytype) !void {
-    var buffer: [128:0]u8 = undefined;
-    const time = interop.timeAsString(io, &buffer, "%Y-%m-%d %H:%M:%S");
+    if (self.maybe_file_writer) |*writer| {
+        var buffer: [128:0]u8 = undefined;
+        const time = interop.timeAsString(io, &buffer, "%Y-%m-%d %H:%M:%S");
 
-    try self.file_writer.interface.print("{s} [info/{s}] ", .{ time, category });
-    try self.file_writer.interface.print(message, args);
-    try self.file_writer.interface.writeByte('\n');
-    try self.file_writer.interface.flush();
+        try writer.interface.print("{s} [info/{s}] ", .{ time, category });
+        try writer.interface.print(message, args);
+        try writer.interface.writeByte('\n');
+        try writer.interface.flush();
+    } else {
+        var buffer: [1024]u8 = undefined;
+        const slice = try std.fmt.bufPrint(&buffer, message, args);
+        const msg = try std.fmt.bufPrintZ(buffer[slice.len..], "[info/{s}] {s}", .{ category, slice });
+
+        std.posix.system.syslog(std.posix.LOG.INFO, msg.ptr);
+    }
 }
 
 pub fn err(self: *LogFile, io: std.Io, category: []const u8, comptime message: []const u8, args: anytype) !void {
-    var buffer: [128:0]u8 = undefined;
-    const time = interop.timeAsString(io, &buffer, "%Y-%m-%d %H:%M:%S");
+    if (self.maybe_file_writer) |*writer| {
+        var buffer: [128:0]u8 = undefined;
+        const time = interop.timeAsString(io, &buffer, "%Y-%m-%d %H:%M:%S");
 
-    try self.file_writer.interface.print("{s} [err/{s}] ", .{ time, category });
-    try self.file_writer.interface.print(message, args);
-    try self.file_writer.interface.writeByte('\n');
-    try self.file_writer.interface.flush();
+        try writer.interface.print("{s} [err/{s}] ", .{ time, category });
+        try writer.interface.print(message, args);
+        try writer.interface.writeByte('\n');
+        try writer.interface.flush();
+    } else {
+        var buffer: [1024]u8 = undefined;
+        const slice = try std.fmt.bufPrint(&buffer, message, args);
+        const msg = try std.fmt.bufPrintZ(buffer[slice.len..], "[info/{s}] {s}", .{ category, slice });
+
+        std.posix.system.syslog(std.posix.LOG.ERR, msg.ptr);
+    }
 }
 
 fn openLogFile(io: std.Io, path: []const u8, log_file: *LogFile) !bool {
     var could_open_log_file = true;
     open_log_file: {
-        log_file.file = std.Io.Dir.cwd().openFile(io, path, .{ .mode = .write_only }) catch std.Io.Dir.cwd().createFile(io, path, .{ .permissions = .fromMode(0o666) }) catch {
+        log_file.maybe_file = std.Io.Dir.cwd().openFile(io, path, .{ .mode = .write_only }) catch std.Io.Dir.cwd().createFile(io, path, .{ .permissions = .fromMode(0o666) }) catch {
             // If we could neither open an existing log file nor create a new
             // one, abort.
             could_open_log_file = false;
@@ -55,17 +90,17 @@ fn openLogFile(io: std.Io, path: []const u8, log_file: *LogFile) !bool {
     }
 
     if (!could_open_log_file) {
-        log_file.file = try std.Io.Dir.openFileAbsolute(io, "/dev/null", .{ .mode = .write_only });
+        log_file.maybe_file = try std.Io.Dir.openFileAbsolute(io, "/dev/null", .{ .mode = .write_only });
     }
 
-    var log_file_writer = log_file.file.writer(io, log_file.buffer);
+    var log_file_writer = log_file.maybe_file.?.writer(io, log_file.buffer);
 
     // Seek to the end of the log file
     if (could_open_log_file) {
-        const stat = try log_file.file.stat(io);
+        const stat = try log_file.maybe_file.?.stat(io);
         try log_file_writer.seekTo(stat.size);
     }
 
-    log_file.file_writer = log_file_writer;
+    log_file.maybe_file_writer = log_file_writer;
     return could_open_log_file;
 }

res/config.ini

@@ -299,6 +299,7 @@ login_defs_path = /etc/login.defs
 logout_cmd = null
 
 # General log file path
+# If null, syslog will be used instead
 ly_log = /var/log/ly.log
 
 # Main box horizontal margin

src/config/Config.zig

@@ -74,7 +74,7 @@ lang: []const u8 = "en",
 login_cmd: ?[]const u8 = null,
 login_defs_path: []const u8 = "/etc/login.defs",
 logout_cmd: ?[]const u8 = null,
-ly_log: []const u8 = "/var/log/ly.log",
+ly_log: ?[]const u8 = "/var/log/ly.log",
 margin_box_h: u8 = 2,
 margin_box_v: u8 = 1,
 numlock: bool = false,