Command Line Interpreter (xwsh)

Overview

XWSH (XWOS Shell) is the command line interpreter module of XWOS, providing users with an interactive command line interface. It is located in the xwmd/cli/xwsh/ directory of the source code and belongs to the command line interface (cli) submodule of the XWOS middleware layer (xwmd).

The core functionality of XWSH includes:

• Command Parsing: Splitting the user-input string into a command name and arguments
• Command Execution: Finding and calling the corresponding command handler function
• Line Editing: Providing history, auto-completion, and other features based on the CherryRL library
• Extension Mechanism: Supporting users adding custom commands

Module Architecture

XWSH adopts a layered design. The relationships between components are as follows:

User Input
    ↓
[m] Readline Layer (CherryRL Integration)
    ↓
[c] Core Layer (Command Parsing and Execution)
    ↓
    ├── [c] Built-in Command Table
    ├── [c] External Command Table (User Extensions)
    └── [c] Command Lookup and Dispatch
        ↓
        [c] Command Handler Functions

• Interface Layer (m): Provides module integration API (mi.h)
• Core Layer (c): Command parsing, execution, management (core.h/core.c)
• Readline Layer: Line editing functionality (readline.h/readline.c)
• Command Layer: Built-in command implementation (cmd.c)

Features

1. Two Running Modes

• Standalone Thread Mode: Creates a dedicated thread to run the Shell
• Embedded Mode: Integrates the Shell loop into an existing thread

2. Command System

• Built-in Commands: help, clear, rd (read memory), wr (write memory)
• External Commands: Supports users dynamically adding custom commands
• Duplicate Name Detection: Prevents command name conflicts

3. Line Editing Features

• History: Supports command history browsing and retrieval
• Auto-completion: Reserved completion interface
• ANSI Escape: Color prompt support

4. Resource Footprint

• Static Memory: No dynamic memory allocation, suitable for embedded environments
• Fixed Buffers: Input buffer 128 bytes, maximum 16 arguments

Directory Navigation

• Core: Command parsing algorithm, thread model, error handling
• Command: Detailed built-in commands, external command adding methods
• Extension: CherryRL library integration details, callback function descriptions
• Integration: Code examples and best practices for both running modes
• API Reference: Detailed descriptions of all public and internal APIs

Quick Start

Standalone Thread Mode

#include "xwmd/cli/xwsh/mi.h"

xwstk_t xwsh_stack[1024];
xwer_t rc = xwsh_start(xwsh_stack, sizeof(xwsh_stack));

Embedded Mode

#include "xwmd/cli/xwsh/mi.h"

xwsh_init();
while (1) {
    char buf[XWSH_MAXINPUT];
    xwsh_loop(buf);
}

Source Code Locations

Note: The XWSH module requires standard input/output (stdin/stdout), typically implemented via serial port or virtual console.