LazTermUtils

About

This small library contains a few classes for managing terminal I/O using ANSI escape sequences. The goal of this unit is provide the functionality provided by the CRT unit (and some more), but optimized for only the most prevalent systems, by only using escape sequences. It was tested under Windows 10 and Linux and allows for writing portable, pretty console applications on both systems.

The functionality include:

• Colorizing output (background, foreground)
• Modifying output (bold, italic, underlined, etc.)
• Reading input keys and modifiers
• Managing terminal window (getting size, jumping around, clearing)
• Non blocking reading of chars and keys

Features:

• Allows to create a Terminal that either uses STDIN, STDOUT and STDERR, or can read and write from files (or tty pseudo files in Linux). This allows even accessing other terminals, e.g. when you want to send a message to all open sessions on a server.
• Supports most widespread Textmodifications like bold, italic, underlined, striked, etc.
• Allows to specify colors as 24 bit values, compatibly with non system LCL colors (like $FF0000 for red)
• Can read keys including their modifications directly, e.g. it can detect ctrl + key or alt + key, as well as support for most special keys
• Allows for both line buffered echoed input and direct invisible input (i.e. where the key is recognized on press and not printed to the terminal)
• Functionality for moving the cursor, clearing the screen and clearing the current line
• Can buffer output to a given size to allow for a better performance (rather than writing each char at a time)
• Provides a cross plattform IsATTY function to check if the handle used is connected to a terminal or a file
• Non blocking read to allow to check if a keypress was made without waiting for it
• UTF-8 support for keystroke reading

License: BSD-2-Clause License

Requirements

This library uses xTerm compatible ANSI escape sequences.

This works with any Terminal emulator supporting this including, but not limited to xTerm, Konsole, GNOME Terminal and the Windows Terminal in Windows 10 (not compatible with older versions of Windows) If the terminal does not support 24 bit (true) color (e.g. the macOS system terminal emulator), you might want to set the define Col8 (only required in TerminalColor.pas), which limits the output to 8bit colors. Lower than that is not supported.

Usage

See the "example" directory for some examples.

• example/ReadkeyExample shows how to read Keystrokes and process them
• example/Colortest colors the whole display (each cell individually) while measuring the FPS to brenchmark the performance of redrawing every cell
• example/Textmods prints text with different modifications. Which of them get displayed correctly depends on your Terminal emulator.
• example/NonBlockingReadTest shows how to use non blocking read to update your view and check for keystrokes single threaded

Download

GitHub repo: https://github.com/Warfley/LazTermUtils