mod: rem zlog dependency; stream line logging structure; do not write ansi control characters when logging to file

.gitignore

@@ -1,2 +1,3 @@
 .zig-cache/
 zig-out/
+log

README.md

@@ -5,6 +5,26 @@ Standard Library log wrapper. `zlog` provides adjusted `std.log` output and a pr
 > [!caution]
 > Only builds using the zig master version are tested to work.
 
+## Install
+
+Add or update this library as a dependency in your zig project run the following command:
+
+```sh
+zig fetch --save git+https://gitea.yves-biener.de/yves-biener/zlog
+```
+
+Afterwards add the library as a dependendy to any module in your *build.zig*:
+
+```zig
+const ztime_dependency = b.dependency("ztime", .{
+  .target = target,
+  .optimize = optimize,
+  .timestamp = true, // default (only required if non-default value shall be used)
+  .stderr = true, // default (only required if non-default value shall be used)
+  .file = "", // default (only required if non-default value shall be used)
+});
+```
+
 ## Usage
 
 The following snippet shows an example usage of `zlog` to change the default log format and add pretty printing to the user defined types:
@@ -58,6 +78,8 @@ const Struct = struct {
 };
 
 pub fn main() void {
+    // without explict scope (i.e. `.default` scope)
+    std.log.info("Without explicit scope or `.default` scope", .{});
     // initialize zlog with the scope of `main`
     const log = std.log.scoped(.main);
     // NOTE the scope of `default` will result in no scoping being printed in
@@ -75,7 +97,7 @@ pub fn main() void {
     const void_tagged_union: TaggedUnion = .nothing;
     const uniun: Union = .{ .boolean = true };
 
-    // NOTE: Depending on the optimization target some of these log messages
+    // NOTE Depending on the optimization target some of these log messages
     // will not show, which is inline with the behavior of `std.log`.
     log.debug("Debug message {any}", .{int_var});
     log.info("Info message {any}", .{array_var});
@@ -87,6 +109,7 @@ pub fn main() void {
     log.err("Error message {any}", .{tagged_union});
 }
 
+// apply *zlog* logging options to `std` logger
 pub const std_options = zlog.std_options;
 
 const std = @import("std");
@@ -96,60 +119,30 @@ const zlog = @import("zlog");
 This will result in the following output:
 
 ```
-[2025-07-17 19:41:43] [debug](main): Debug message 42
+2025/11/02 11:57:29 [info] Without explicit scope or `.default` scope
-[2025-07-17 19:41:43] [info](main): Info message { 1, 2, 3, 4 }
+2025/11/02 11:57:29 [debug](main) Debug message 42
-[2025-07-17 19:41:43] [info](main): Info message "This is a test"
+2025/11/02 11:57:29 [info](main) Info message { 1, 2, 3, 4 }
-[2025-07-17 19:41:43] [warning](main): Warning message main.Options = enum {
+2025/11/02 11:57:29 [info](main) Info message "This is a test"
-	a,
+2025/11/02 11:57:29 [warning](main) Warning message .a
-	b,
+2025/11/02 11:57:29 [warning](main) Warning message .{ .nothing = void }
-	c,
+2025/11/02 11:57:29 [warning](main) Warning message .{ ... }
-} = .a
+2025/11/02 11:57:29 [error](main) Error message .{ .a = 42, .b = true, .c = { 1, 2, 3, 4, 5 }, .d = { 115, 116, 114, 105, 110, 103 }, .e = .b, .f = .{ .one = -5 } }
-[2025-07-17 19:41:43] [warning](main): Warning message main.TaggedUnion = union(enum) {
+2025/11/02 11:57:29 [error](main) Error message .{ .three = { 84, 104, 114, 101, 101 } }
-	one: i16,
-	two: u32,
-	three: []const u8,
-	nothing,
-} = .{ .nothing = void }
-[2025-07-17 19:41:43] [warning](main): Warning message main.Union = union {
-	int: i32,
-	boolean: bool,
-} = @7fffd1c71048
-[2025-07-17 19:41:43] [error](main): Error message main.Struct = struct {
-	.a = 42,
-	.b = true,
-	.c = []u16: { 1, 2, 3, 4, 5 },
-	.d = "string",
-	.e = main.Options = enum {
-		a,
-		b,
-		c,
-	} = .b,
-	.f = main.TaggedUnion = union(enum) {
-		one: i16,
-		two: u32,
-		three: []const u8,
-		nothing,
-	} = .{ .one = -5 },
-}
-[2025-07-17 19:41:43] [error](main): Error message main.TaggedUnion = union(enum) {
-	one: i16,
-	two: u32,
-	three: []const u8,
-	nothing,
-} = .{ .three = "Three" }
 ```
 
 ## Customization
 
 For more details about the output customization see the configuration options of the `zlog` module. Following options are available:
 
-- *timestamp* (default: `true`): Prepend the current timestamp before each log message.
+- *timestamp* (default: `true`): Prepend the current timestamp before each log message. If disabled the date and time (i.e. `2025/11/02 11:57:29 `) are not prepended to each log message.
 - *stderr* (default: `true`): Print log messages to stderr.
-- *file* (default: `""`): File path to log messages to. Without a path no log file will be created and logged to. Can be used in parallel with the *stderr* option
+- *file* (default: `""`): File path to log (appending; creates if does not exist) messages to. Without a path no log file will be created and logged to. Can be used in parallel with the *stderr* option.
 
-## Tips
+---
 
-The following list shows some tips on how to use logging more effectively. These tips do not apply just to `zlog` (and not even only to zig code).
+> [!tip]
+> The following list shows some tips on how to use logging more effectively.
+> These tips do not apply just to `zlog` (and not even only to zig code).
 
 - Use `errdefer` to directly print messages on failures in the same function they occur:
   ```zig
@@ -162,4 +155,4 @@ The following list shows some tips on how to use logging more effectively. These
     break :port try fmt.parseInt(u16, buf[0 .. len -| 1], 10);
   };
   ```
-- When looking through the output of the log (i.e. written to disk by `program 2> log` when using the _stderr_ build option) the `log` file contains control code characters (*ansi*) for the colored outputs. You can still see them correctly with the following command `less -R log`.
+- When looking through the output of the log (i.e. written to disk by `program 2> log` when using the *stderr* build option) the `log` file contains control code characters (*ansi*) for the colored outputs. You can still see them correctly with the following command `less -R log`. When using the *file* build option the *ansi* control characters are not omitted when logging to the file.

build.zig

@@ -27,11 +27,6 @@ pub fn build(b: *std.Build) void {
     // set a preferred release mode, allowing the user to decide how to optimize.
     const optimize = b.standardOptimizeOption(.{});
 
-    const ztime_dependency = b.dependency("ztime", .{
-        .target = target,
-        .optimize = optimize,
-    });
-
     const zlog_module = b.addModule("zlog", .{
         // In this case the main source file is merely a path, however, in more
         // complicated build scripts, this could be a generated file.
@@ -39,7 +34,6 @@ pub fn build(b: *std.Build) void {
         .target = target,
         .optimize = optimize,
         .imports = &.{
-            .{ .name = "ztime", .module = ztime_dependency.module("ztime") },
             .{ .name = "build_options", .module = options_module },
         },
     });
@@ -51,7 +45,6 @@ pub fn build(b: *std.Build) void {
             .target = target,
             .optimize = optimize,
             .imports = &.{
-                .{ .name = "ztime", .module = ztime_dependency.module("ztime") },
                 .{ .name = "zlog", .module = zlog_module },
             },
         }),
@@ -93,7 +86,6 @@ pub fn build(b: *std.Build) void {
             .target = target,
             .optimize = optimize,
             .imports = &.{
-                .{ .name = "ztime", .module = ztime_dependency.module("ztime") },
                 .{ .name = "build_options", .module = options_module },
             },
         }),

build.zig.zon

@@ -1,16 +1,10 @@
 .{
     .name = .zlog,
+    // This is a [Semantic Version](https://semver.org/).
+    .version = "0.16.0",
     .fingerprint = 0x55b82e3347a594e8,
-    // version name should match the zig version except for the last number,
+    .minimum_zig_version = "0.16.0-dev.463+f624191f9",
-    // which stands for the version inside a given zig version
+    .dependencies = .{},
-    .version = "0.15.0",
-    .dependencies = .{
-        .ztime = .{
-            .url = "git+https://gitea.yves-biener.de/yves-biener/ztime#6a2f853f36aa55146e089d7c0c3f041012c0f8fe",
-            .hash = "ztime-0.0.0-e3nBJL5xAAC_guuqgVnOZncpvwH76NnKRC7JJ_zTF9rV",
-        },
-    },
-    .minimum_zig_version = "0.15.0",
     .paths = .{
         "build.zig",
         "build.zig.zon",

src/main.zig

@@ -46,6 +46,8 @@ const Struct = struct {
 };
 
 pub fn main() void {
+    // without explict scope (i.e. `.default` scope)
+    std.log.info("Without explicit scope or `.default` scope", .{});
     // initialize zlog with the scope of `main`
     const log = std.log.scoped(.main);
     // NOTE the scope of `default` will result in no scoping being printed in
@@ -63,7 +65,7 @@ pub fn main() void {
     const void_tagged_union: TaggedUnion = .nothing;
     const uniun: Union = .{ .boolean = true };
 
-    // NOTE: Depending on the optimization target some of these log messages
+    // NOTE Depending on the optimization target some of these log messages
     // will not show, which is inline with the behavior of `std.log`.
     log.debug("Debug message {any}", .{int_var});
     log.info("Info message {any}", .{array_var});
@@ -75,6 +77,7 @@ pub fn main() void {
     log.err("Error message {any}", .{tagged_union});
 }
 
+// apply *zlog* logging options to `std` logger
 pub const std_options = zlog.std_options;
 
 const std = @import("std");

src/root.zig

@@ -5,18 +5,17 @@ fn logFn(
     comptime format: []const u8,
     args: anytype,
 ) void {
-    const prefix = if (scope == .default) ": " else "(\x1b[2m" ++ @tagName(scope) ++ "\x1b[0m): ";
-    // TODO this should only happen for messages that are written to *stderr* in files the escape codes are only annoying
-    const level_txt = switch (comptime message_level) {
-        .err => "[\x1b[38;5;9merror\x1b[0m]",
-        .warn => "[\x1b[38;5;11mwarning\x1b[0m]",
-        .info => "[\x1b[38;5;10minfo\x1b[0m]",
-        .debug => "[\x1b[38;5;12mdebug\x1b[0m]",
-    };
-    // TODO let user configure the format he wants to use for logging and use a pretty good default one?
-    const complete_format = level_txt ++ prefix ++ format ++ "\n";
     var buf: [128]u8 = undefined;
     if (comptime build_options.file.len > 0) {
+        const prefix = if (scope == .default) " " else "(" ++ @tagName(scope) ++ ") ";
+        const level_txt = switch (comptime message_level) {
+            .err => "[error]",
+            .warn => "[warning]",
+            .info => "[info]",
+            .debug => "[debug]",
+        };
+        // TODO let user configure the format he wants to use for logging and use a pretty good default one?
+        const complete_format = level_txt ++ prefix ++ format ++ "\n";
         // TODO use common logging format, such that in integrates well with other logging frameworks
         // (i.e. golang's logger, log4j, etc.)
         const fd = std.posix.open(build_options.file, .{
@@ -28,32 +27,63 @@ fn logFn(
 
         var buffer = std.fs.File.Writer.init(.{ .handle = fd }, &buf);
         var writer = &buffer.interface;
-        defer writer.flush() catch {};
+        defer writer.flush() catch unreachable;
 
-        log_writing(writer, complete_format, args);
+        log_writing(writer, complete_format, false, args);
     }
 
     if (comptime build_options.stderr) {
+        const prefix = if (scope == .default) " " else "(\x1b[2m" ++ @tagName(scope) ++ "\x1b[0m) ";
+        const level_txt = switch (comptime message_level) {
+            .err => "[\x1b[38;5;9merror\x1b[0m]",
+            .warn => "[\x1b[38;5;11mwarning\x1b[0m]",
+            .info => "[\x1b[38;5;10minfo\x1b[0m]",
+            .debug => "[\x1b[38;5;12mdebug\x1b[0m]",
+        };
+        const complete_format = level_txt ++ prefix ++ format ++ "\n";
+
         var buffer = stderr().writer(&buf);
         var writer = &buffer.interface;
-        defer writer.flush() catch {};
+        defer writer.flush() catch unreachable;
 
         std.debug.lockStdErr();
         defer std.debug.unlockStdErr();
 
-        log_writing(writer, complete_format, args);
+        log_writing(writer, complete_format, true, args);
     }
 }
 
-inline fn log_writing(writer: *std.Io.Writer, comptime format: []const u8, args: anytype) void {
+inline fn log_writing(writer: *std.Io.Writer, comptime format: []const u8, comptime ansi: bool, args: anytype) void {
     nosuspend {
-        if (build_options.timestamp) log_timestamp(writer);
+        if (build_options.timestamp) log_timestamp(writer, ansi);
         writer.print(format, args) catch return;
     }
 }
 
-inline fn log_timestamp(writer: anytype) void {
+/// Prepend the current timestamp in the following format:
-    writer.print("[\x1b[1m{any}\x1b[0m] ", .{ztime.DateTime.now()}) catch return;
+/// `<year>/<month>/<day> <hour>:<minute>:<sec> `
+///
+/// NOTE all information are displayed using numbers
+inline fn log_timestamp(writer: anytype, comptime ansi: bool) void {
+    const time = std.posix.clock_gettime(.REALTIME) catch @panic("Cannot request timestamp");
+    const epoch_secs: std.time.epoch.EpochSeconds = .{ .secs = @intCast(time.sec) };
+    const day_secs = epoch_secs.getDaySeconds();
+    const year_and_day = epoch_secs.getEpochDay().calculateYearDay();
+    const month_and_day = year_and_day.calculateMonthDay();
+    writer.print(
+        if (comptime ansi)
+            "\x1b[1m{d}/{d:0>2}/{d:0>2} {d:0>2}:{d:0>2}:{d:0>2}\x1b[0m "
+        else
+            "{d}/{d:0>2}/{d:0>2} {d:0>2}:{d:0>2}:{d:0>2} ",
+        .{
+            year_and_day.year,
+            month_and_day.month.numeric(),
+            month_and_day.day_index + 1,
+            day_secs.getHoursIntoDay(),
+            day_secs.getMinutesIntoHour(),
+            day_secs.getSecondsIntoMinute(),
+        },
+    ) catch return;
 }
 
 pub fn pretty_format(object: anytype, comptime format: []const u8, options: fmt.FormatOptions, writer: anytype) !void {
@@ -197,4 +227,3 @@ const stderr = fs.File.stderr;
 const log = std.log;
 const fmt = std.fmt;
 const build_options = @import("build_options");
-const ztime = if (build_options.timestamp) @import("ztime") else null;