center - Centers text from stdin! 🛠️

center reads input from stdin, calculates the width of each line (considering multibyte characters), and center-aligns the text within the terminal window. Fully supports UTF-8.

Originally by Lizzy Fleckenstein 🤍

Highlights

• Terminal size detection: Adjusts text to fit the terminal width.
• Multibyte support: Properly handles UTF-8 Unicode characters.
• Text centering: Prints each line centered within the terminal.
• Error handling: Graceful handling of system call failures.

Getting Started

Prerequisites

If you are building center, you'll need:

• A C compiler that supports C99 or later.

Installing

If you have Homebrew installed, just run:

brew install Neved4/homebrew-tap/center

Implementation

center operates as follows:

1. Opens /dev/tty to get the terminal width.
2. Reads input line-by-line.
3. Calculates character width (supporting multibyte characters).
4. Prints each line centered in the terminal.

Examples

Below is an example of how the center command works in practice:

$ echo 'Hello World!' | center
                                  Hello World!

Compatibility

Runs on Linux, macOS and *BSD systems on x86_64 and arm64, and compiles with zig, clang, gcc, tcc and any other compiler that supports C99 or later.

Standards

center is compatible with POSIX.1-2024¹ as well as the C23² standard.

See Also

For further reference and related tools, check out the following:

• LizzyFleckenstein03/center

License

center is licensed under the terms of the GPLv3 License.

See the LICENSE file for details.

Footnotes

1. IEEE Std 1003.1-2024: Standard for Information Technology — Portable Operating System Interface (POSIX®),
   ISO/IEC DIS 9945. URL: https://pubs.opengroup.org/onlinepubs/9799919799/ ↩

2. ISO/IEC 9899: Standard for Information Technology — Programming languages — C, ISO/IEC 9899:2023.
   URL: https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf ↩