Microrl

microrl - micro read line library for small and embedded devices with basic VT100 support.

• Description
• Feature
• Src structure
• Install
• Usage
  • Examples

Description

Microrl library is designed to help implement command line interface in small and embedded devices. Main goal is to write compact, small memory consuming but powerful interfaces, with support navigation through command line with cursor, HOME, END keys, hot key like Ctrl+U and other, history and completion feature.

Feature

• config.h file

  • Turn on/off feature for add functional/decrease memory via config files.

• hot keys support

  • backspace, cursor arrow, HOME, END keys
  • Ctrl+U (cut line from cursor to begin)
  • Ctrl+K (cut line from cursor to end)
  • Ctrl+A (like HOME)
  • Ctrl+E (like END)
  • Ctrl+H (like backspace)
  • Ctrl+B (like cursor arrow left)
  • Ctrl+F (like cursor arrow right)
  • Ctrl+P (like cursor arrow up)
  • Ctrl+N (like cursor arrow down)
  • Ctrl+R (retype prompt and partial command)
  • Ctrl+C (call 'sigint' callback, only for embedded system)

• history

  • Static ring buffer history for memory saving. Number of commands saved to history depends from commands length and buffer size (defined in config)

• completion

  • via completion callback

Src structure

src/             - library source
  microrl.c      - microrl routines
  microrl.h      - lib interface and data type
  config.h       - customisation config-file
examples/        - library usage examples
  avr_misc/      - avr specific routines for avr example
  unix_misc/     - unix specific routines for desktop example
  example.c      - common part of example, for build  demonstrating example for various platform
  example_misc.h - interface to platform specific routines for example build (avr, unix)
  Makefile       - unix example build (gcc)
  Makefile.avr   - avr example build (avr-gcc)

Install

Requirements: C compiler with support for C99 standard (GNU GCC, Keil, IAR) with standard C library (libc, uClibc or other compatible). Also you have to implement several routines in your own code for library to work. NOTE: need add -std=gnu99 arg for gcc

Usage

For embed lib to you project, you need to do few simple steps:

1. Include microrl.h file to you project.

2. Create microrl_t object, and call microrl_init func, with print callback pointer. Print callback pointer is pointer to function that call by library if it's need to put text to terminal. Text string always is null terminated. For example on linux PC print callback may be:

	// print callback for microrl library
	void print (char * str)
	{
		fprintf (stdout, "%s", str);
	}

3. Call microrl_set_execute_callback with pointer to you routine, what will be called if user press enter in terminal. Execute callback give a 'argc', 'argv' parametrs, like 'main' func in application. All token in 'argv' is null terminated. So you can simply walk through argv and handle commands.

4. If you want completion support if user press TAB key, call microrl_set_complete_callback and set you callback. It also give 'argc' and 'argv' arguments, so iterate through it and return set of complete variants.

5. Look at 'config.h' file. If you want to override some configuration, please compile with MICRORL_INCLUDE_CONFIG_H and provide a header file named microrl_config.h.

6. Now you just call microrl_insert_char on each char received from input stream (usart, network, etc).

Examples

//*****************************************************************************
int main (int argc, char ** argv)
{
	// create microrl object and pointer on it
	microrl_t rl;
	microrl_t * prl = &rl;
	struct microrl_config config = {
		// set print callback
		.print = print,
		// set callback for completion (optionally)
		.get_completion = complet,
		// set callback for execute
		.execute = execute,
		// set callback for ctrl+c handling (optionally)
		.sigint = sigint
	};
	// call init with ptr to microrl instance and configuration
	microrl_init (prl, &config);
	
	while (1) {
		// put received char from stdin to microrl lib
		char ch = get_char ();
		microrl_insert_char (prl, ch);
	}
	return 0;
}

See examples library usage.

Author: Eugene Samoylov aka Helius (ghelius@gmail.com) 01.09.2011