cli-embedded

A simple command-line interface for use in embedded systems. This useful tool allows a user to remotely invoke functions on their device by specifing commands (and parameters) over a byte stream protocol.

Features

• Remotely invoke functions on device.
• Ability to process function parameters.
• Statically allocated memory.
• Backspace to remove unintentional keypresses.

Introduction

This package contains files to implement a simple command-line interface. The package includes cli.h, and cli.c.

Integration details

• Integrate cli.h and cli.c files into your project.
• Include the cli.h header file in your code like below.

#include "cli.h"

File information

• cli.h : This header file contains the definitions of the cli user API.
• cli.c : This source file contains the implementation of the CLI.

Supported interfaces

• Typically, UART.
• .. Any byte-stream based interface.

Integration Guide

Initialising the CLI

To correctly set up the CLI, the user must do four things:

1. Create a table of commands which are to be accepted by the CLI, using the cmd_t structure.

Note: Command functions must use the cli_status_t (*func)(int argc, char **argv) definition.

cmd_t cmds[2] = {
    {
        .cmd = "help",
        .func = help_func
    },
    {
        .cmd = "echo",
        .func = echo_func
    }
};

2. Place the cli_put() function within the devices interrupt handler responsible for receiving 1 byte over the communication protocol.

void UART_Rx_IrqHandler()
{
    char c = UART->RxData;
    cli_put(&cli, c);
}

3. Create an instance of the CLI handle structure, and fill in the required parameters.

cli_status_t rslt = CLI_OK;

cli_t cli = {
    .println = user_uart_println,
    .cmd_tbl = cmds,
    .cmd_cnt = sizeof(cmds)
};

if((rslt = cli_init(&cli)) != CLI_OK)
{
    printf("CLI: Failed to initialise");
}

4. Periodically call the cli_process() function in order to process incoming commands.

User Guide

To interface with the CLI, the user must open a communication stream on their chosen protocol (typically UART). The default end-of-delimiter used by the application is '\n', however this can be changed. The user can invoke their functions by sending: echo <param>\n

• echo, the name of the command
• , first parameter (if required).

Function templates

cli_status_t user_uart_println(char *string)
{
    /* For example.. */
    if(HAL_UART_Transmit_IT(&huart, string, strlen(string)) != HAL_OK)
        return SLI_E_IO;
    
    return SLI_OK;
}

cli_status_t help_func(int argc, char **argv)
{
    cli_status_t rslt = CLI_OK;

    /* Code executed when 'help' is entered */

    return rslt;
}

cli_status_t echo_func(int argc, char **argv)
{
    cli_status_t rslt = CLI_OK;

    /* Code executed when 'echo' is entered */

    return rslt;
}