Lapel

Lapel is a CLI shell suitable for porting to a microcontroller or embedding within a general purpose application. It can be made to work over any reliable serial interface.

Features

• multi-line editing
• line completions (tab)
• line history (up/down)
• argument tokenizer supporting quotes and escape characters
• getopt argument parser with support for long and short options
• users are optional
  • optional out-of-band login (e.g. if transport layer provides authentication)
  • optional username and pasword prompt
  • role based access control
• multiple shell instances are possible
• command handlers may yield to wait for input without blocking (and can be 'terminated' by ctrl-c)

Limitations / Caveats

• requires a C++ compiler (C++11 and up)
• no redirection, pipes, scripts, and other sophisticated features you might expect in a real shell
• no concept of file system (for now)
• ascii only
• line buffers are allocated from heap

Builtin Commands

• help
• clear: clear screen
• resize: specify the size or ask shell to discover using DSR control code
• logout: logout user
• echo: echo back the arguments

Examples

• raw terminal
• Arduino

Serial Terminal Compatibility

Lapel has been confirmed to work with the following serial terminals:

• GNU Screen
• Putty

Building

• create lapel_config.h somewhere in search path (lapel source includes this file)
• add include to search path
• compile sources in src

There are some preprocessor options which can be defined in lapel_config.h:

#define LAPEL_DEBUG(...)

Print debug messages.

#define LAPEL_ERROR(...)

Print error messages.

#define LAPEL_ASSERT(X)

Implement assert.

License

See LICENSE and NOTICE files.