tock

A digital clock for the terminal, inspired by tty-clock. Unfortunately only works on UNIX systems due to the use of the termios and sigaction related function calls.

Note: emulating all features of tty-clock is not a goal of this project.

Features

• Efficient bitmap and diff-based drawing
• Timezone support via the TZ environment variable and tzselect utility
• Military time and second display toggling
• Color customization using ANSI, 8-bit, or 24-bit color values
• Arbitrary date formatting
• Positioned or centered clock
• Adjustable display size
• Synchronization with system clock seconds
• Minimal syscalls (about one read, write, nanosleep per second)

Screenshots

Installation

Currently requires a Rust installation, and is only available from either:

1. crates.io

$ cargo install tock

2. Building from source

$ git clone https://github.com/nwtnni/tock.git
$ cargo build --release
$ ./target/release/tock

Usage

USAGE:
    tock [FLAGS] [OPTIONS]

FLAGS:
    -c, --center
            Center the clock in the terminal.
            Overrides manual positioning.

        --help
            Prints help information

    -m, --military
            Display military (24-hour) time.

    -s, --seconds
            Display seconds.

    -V, --version
            Prints version information


OPTIONS:
    -C, --color <color>
            Change the color of the time.

            Accepts either a [single 8-bit number][0] or
            three comma-separated 8-bit numbers in R,G,B format.
            Does not check if your terminal supports the
            entire range of 8-bit or 24-bit colors.

            [0]: https://en.wikipedia.org/wiki/ANSI_escape_code#8-bit

            [default: 2]

    -f, --format <format>
            Change the date format.

            Accepts a format string using [strftime][0] notation.
            Note that occurrences of the `%Z` specifier are
            naively replaced with the contents of the `TZ` environment
            variable, or the string "Local" if `TZ` is not set.

            [0]: https://docs.rs/chrono/0.4.6/chrono/format/strftime/index.html

            [default: %F | %Z]

    -h, --height <h>
            Font height in characters per tile. [default: 1]

    -w, --width <w>
            Font width in characters per tile. [default: 2]

    -x, --x <x>
            Horizontal 0-indexed position of top-left corner.

            [default: 1]

    -y, --y <y>

Currently compiles with the interactive feature flag set by default, which polls stdin for user input once per second. Available commands with this feature flag set are:

• q or Q or <ESC>: Exit.
• s: Toggle second display.
• m: Toggle military (24H) time.
• 0..=7: Change to corresponding ANSI color.

Changelog

• 0.1.4

  • Refactor drawing algorithms for readability.
  • Fix comparison function for Date to avoid redrawing .

• 0.1.3

  • Draw clock to alternate screen buffer to avoid clearing user information. Thanks @Canop!

• 0.1.2

  • Fix README formatting (oops).

• 0.1.1

  • Implement support for date formatting strings via -f option.
  • Fix logic in Brush abstraction by only setting dried flag after writing.

• 0.1.0

  • Initial release.

References

• How Not to Write a Signal Handler
• What is the difference between sigaction and signal?
• A Brief Introduction to termios: termios(3) and stty
• Understanding UNIX termios VMIN and VTIME
• Specifying the Time Zone with TZ
• min-sized-rust