This is a syslog client library for Zig:
| Protocols | UDP, TCP |
| RFC | Subset of RFC5424 |
| Tested on | Mac, Windows, Linux |
For the curious: IT Explained: Syslog
When client code calls
logger.write_info("Hello, Zig!");
syslog client sends following text message to syslog receiver process:
<190>1 2024年10月09日T09:07:11+00:00 BLKF zigprocess 18548 1 - Hello, Zig!
Let's see what this message consist of:
| Value | RFC Definition | Description |
|---|---|---|
| 190 | PRIVAL | Priority |
| 1 | VERSION | Always 1 |
| 2024年10月09日T09:07:11+00:00 | TIMESTAMP | FULL-DATE "T" FULL-TIME |
| BLKF | HOSTNAME | Hostname or '-' |
| zigprocess | APP-NAME | Application name provided by caller |
| 18548 | PROCID | Process ID or '-' |
| 1 | MSGID | Message ID - sequential number generated automatically |
| - | STRUCTURED-DATA | Always '-' |
| Hello, Zig! | MSG | Message |
Priority = Facility * 8 + Severity
Facility represents the machine process that created the Syslog event
| rfc5424.Facility | Value | Description |
|---|---|---|
| .kern | 0 | kernel messages |
| .user | 1 | random user-level messages |
| 2 | mail system | |
| .daemon | 3 | system daemons |
| .auth | 4 | security/authorization messages |
| .syslog | 5 | messages generated internally by syslogd |
| .lpr | 6 | line printer subsystem |
| .news | 7 | network news subsystem |
| .uucp | 8 | UUCP subsystem |
| .cron | 9 | clock daemon |
| .authpriv | 10 | security/authorization messages (private) |
| .ftp | 11 | ftp daemon |
| .local0 | 16 | local use 0 |
| .local1 | 17 | local use 1 |
| .local2 | 18 | local use 2 |
| .local3 | 19 | local use 3 |
| .local4 | 20 | local use 4 |
| .local5 | 21 | local use 5 |
| .local6 | 22 | local use 6 |
| .local7 | 23 | local use 7 |
Severity describes the severity level of the syslog message in question.
| Level | rfc5424.Severity | Description |
|---|---|---|
| 0 | .emerg | system is unusable |
| 1 | .alert | action must be taken immediately |
| 2 | .crit | critical conditions |
| 3 | .err | error conditions |
| 4 | .warning | warning conditions |
| 5 | .notice | normal but significant condition |
| 6 | .info | informational |
| 7 | .debug | debug-level messages |
What are Facility and Severity of "Hello, Zig!" message?
- What is Syslog?
- syslog-ng Open Source Edition
- The rocket-fast system for log processing
- Old brave syslogd
- Kafka syslog connector
- Nats syslog connector
Add syslog to build.zig.zon:
zig fetch --save=syslog git+https://github.com/g41797/syslog
Add syslog to build.zig:
const syslog = b.dependency("syslog", .{ .target = target, .optimize = optimize, }); const lib = b.addStaticLibrary(..); lib.root_module.addImport("syslog", syslog.module("syslog")); const lib_unit_tests = b.addTest(...); lib_unit_tests.root_module.addImport("syslog", syslog.module("syslog"));
Import syslog:
const syslog = @import("syslog");
syslog uses following configuration:
pub const SyslogOpts = struct { // application: name: []const u8 = "zigprocess", fcl: rfc5424.Facility = .local7, // transport: proto: Protocol = .udp, addr: []const u8 = "127.0.0.1", port: u16 = 514, };
var logger: syslog.Syslog = .{}; try logger.init(std.testing.allocator, .{ .name = "runner", .fcl = .daemon .port = 12345, }); defer logger.deinit();
After initialization you can call syslog on different threads.
There are two groups of APIs:
- write: message is straight text
pub inline fn write_<severity>(slog: *Syslog, msg: []const u8) !void {...} .... logger.write_debug("Hello, Zig!");
- print: message will be formatted before send
pub inline fn print_<severity>(slog: *Syslog, comptime fmt: []const u8, msg: anytype) !void {...} .... const name = "World"; logger.print_debug("Hello, {s}!", .{name});
Set filter:
// disable send messages with .info & .debug severities logger.setfilter(.info);// disable send messages with .info & .debug severities
Reset filter:
logger.setfilter(null);
The following refactoring was performed by Claude Code:
- Explicit Pointer Dereferencing: Removed "Automatic pointer dereference" and replaced it with explicit
ptr.*syntax. - Explicit Type Declaration: Removed "Type Inference" by adding explicit types to all variable declarations.
Related configuration files and guidelines are located in the .claude/rules directory.