Initial commit

.editorconfig

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+root = true
+
+[*]
+end_of_line = lf
+insert_final_newline = true
+trim_trailing_whitespace = true
+
+[*.go]
+indent_style = tab
+indent_size = 4

.gitattributes

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+tools/**   linguist-vendored
+Dockerfile linguist-vendored

Dockerfile

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+FROM golang:latest
+WORKDIR /app
+COPY twc.go /app
+ENV CFLAGS=-O2
+RUN go build -o twc .
+CMD ["./twc"]

LICENSE

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+MIT License
+
+Copyright (C) 2023 Neveda
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

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+![Go](https://img.shields.io/badge/Go-00ADD8?logo=go&logoColor=fff)
+[![CodeQL](https://github.com/github/docs/actions/workflows/codeql.yml/badge.svg)](https://github.com/Neved4/twc/actions/workflows/codeql.yml)
+
+# `twc.go` - simple world clock in Go 🦦
+
+Fast, CLI world clock that displays time zone information using
+[tz database] to read valid [tz entries].
+
+```console
+$ twc -h -f tools/samples/tz-small.conf
+America/New_York     2023-12-11 12:37:13
+America/Los_Angeles  2023-12-11 09:37:13
+UTC                  2023-12-11 17:37:13
+Europe/London        2023-12-11 17:37:13
+Europe/Paris         2023-12-11 18:37:13
+Asia/Tokyo           2023-12-12 02:37:13
+Australia/Sydney     2023-12-12 04:37:13
+```
+
+### Highlights
+
+- 🚀 _**Fast**_ - **10X times faster than [twc.c], 65X times faster than
+  `date`**.[^1] Only ≈ `7 ms` for one entry, and ≈ `177 ms` for ≈ 600
+  entries.
+- 🔒 _**Robust**_ - tested to work with all [tz database] entries,
+  `version 2023c`.
+- 📦 **Self-contained** - zero dependencies,
+  lighweight (`1555 bytes`, `67 lines`).
+
+## Getting Started
+
+### Setup
+
+Clone the repository:
+
+```sh
+git clone https://github.com/Neved4/twc
+```
+
+Build:
+
+```console
+$ go build twc.go
+```
+
+### Usage
+
+```
+flag provided but not defined: -z
+Usage of ./twc:
+  -f string
+    	Specify file path (default "tz-small.conf")
+  -h	Print human-readable format
+  -s string
+    	Specify time format
+  -t string
+    	Specify timezone directly
+
+Examples:
+    $ twc -h -s %Y-%m-%d -t Asia/Tokyo
+        2006-01-02
+
+    $ TZ=America/Los_Angeles twz
+        2006-01-02T15:04:05-0800
+
+Environment:
+    TZ  Timezone to use when displaying dates.
+
+See also:
+    environ(7)
+```
+
+## Compatibility
+
+Runs on _**Linux**_, _**macOS**_ and _**\*BSD**_ systems on [`x86_64`] and
+[`arm64`], and compiles with and any other.
+
+## License
+                 
+`twc` is licensed under the terms of the [MIT License].
+
+See the [LICENSE](LICENSE) file for details.
+
+[`hyperfine`]: https://github.com/sharkdp/hyperfine
+[`twc.c`]: https://github.com/Neved4/twc
+[`arm64`]: https://en.wikipedia.org/wiki/AArch64
+[`x86_64`]: https://en.wikipedia.org/wiki/X86-64
+[MIT License]: https://opensource.org/license/mit/
+[tz database]: https://en.wikipedia.org/wiki/Tz_database
+[tz entries]: https://en.wikipedia.org/wiki/List_of_tz_database_time_zones
+
+[^1]: _cfr._ `date` command that takes ≈ `931 ms` for ≈ `600` entries.
+    Measured with [`hyperfine`].
+[^2]: _IEEE Std 1003.1-2017: Standard for Information Technology
+    — Portable Operating System Interface (POSIX®)_, \
+    ISO/IEC/IEEE 9945:2009/COR 2:2017. URL: https://pubs.opengroup.org/onlinepubs/9699919799/
+[^3]: _ISO/IEC 9899:2023: Standard for Information Technology
+    — Programming languages — C_, ISO/IEC 9899:2023. \
+    URL: https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf

tools/samples/tz-small.conf

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+America/New_York
+America/Los_Angeles
+UTC
+Europe/London
+Europe/Paris
+Asia/Tokyo
+Australia/Sydney