Getting local time

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1

There is no way to get local time without touching c or 3rd party libs??

2

Maybe this helps you
std.Io.Clock
But the way I implemented getting localtime was with C:

const ctime = @cImport(@cInclude("time.h"));
fn formatCurrentTime(_: void, w: *std.Io.Writer) !void {
    const time = try w.writableSliceGreedy(64);
    var now: ctime.time_t = ctime.time(null);
    const timeinfo = ctime.localtime(&now);
    const fmt = "%b %d %H:%M:%S"; // Example: "Oct 30 12:47:23"
    const time_len = ctime.strftime(time.ptr, time.len, fmt, timeinfo);
    w.advance(time_len);
}
// Or this:
fn currentTime(buf: []u8) ![]u8 {
    var now: ctime.time_t = ctime.time(null);
    const timeinfo = ctime.localtime(&now);
    const fmt = "%b %d %H:%M:%S"; // Example: "Oct 30 12:47:23"
    const len = ctime.strftime(buf.ptr, buf.len, fmt, timeinfo);
    if (len == 0) return error.FormatFailed;
    return buf[0..len];
}

I’m quite new to programming and Zig also. If there is anyone with a better approach or knows more I’d like to see it as well :smiley:

1 Like
3

Yea I started implementing this with c but decided to stop. Cannot justify this if I already imported std. 100+ LOC to get a local time string in a conventional format sounds absolutely ridiculous)). Your solution is not thal long, but I am trying to keep this one clean without any C.

4

The relevant issue is

2 Likes
5

I have a zig library for this. Feel free to vendor whatever you need and delete what you don’t. GitHub - rockorager/zeit: a date and time library written in zig. Timezone, DST, and leap second aware

6 Likes
6

Actually there are a couple of approaches in Zig by now, see e.g. GitHub - zigcc/awesome-zig: A collection of some awesome public Zig programming language projects.

What I like about the C approach @charlie is that it offers a handy “bypass” of all the timezone stuff

7

DATE and TIMESTAMP field management

8

ended up with this fn

const time = @cImport(@cInclude("time.h"));
fn updateSyncTime(self: *SyncQueue, allocator: std.mem.Allocator) !void {
    if (self.sync_time) |old_val| allocator.free(old_val);
    var buf: [16]u8 = undefined;
    var time_str: time.tm = undefined;
    var current_time = time.time(null);
    const local = time.localtime_r(&current_time, &time_str); // C23
    const format = "%b %d %H:%M:%S";
    const len = time.strftime(&buf, buf.len, format, local);
    self.sync_time = try allocator.dupe(
        u8,
        if (len == 0) "unknown" else buf[0..len],
    );
}

you might want to drop deprecated localtime

1 Like