一个最简单的CLI命令行界面实现

#include "system.h"
#include "utils/ui.h"
#include "appl/cli.h"
/*
cli命令行界面，一共可以注册MAX_CLI_COMMANDS 个命令，命令名字可以是[A-Z,a-z,0-9]的某个字母。
运行效果：
CMD> F - Flash utilities
  f - Write factory mac address
  n - Write the serial number
  d - Dump the mac address and serial number
Enter your choice: f
Mac: 00-22-44-66-88-00
*/

#if CFG_CLI_ENABLED
#define MAX_CLI_COMMANDS        (26+26+10)  /* Lower + upper + digit */

/* Commands forward */
APISTATIC void cli_cmd_list_commands(CLI_CMD_OP op) REENTRANT;
APISTATIC void cli_cmd_command_help(CLI_CMD_OP op) REENTRANT;

extern void APIFUNC(cli_init)(void) REENTRANT;

/* 
 * Command list 
 *
 * Note: We use STATIC initializer because commands could be added during
 *       system initialization phase.
 */
STATIC CLI_CMD_FUNC cmds[MAX_CLI_COMMANDS]; //命令列表
/*查找所有已添加命令并执行命令描述*/
APISTATIC void
APIFUNC(cli_cmd_list_commands)(CLI_CMD_OP op) REENTRANT
{
    if (op == CLI_CMD_OP_HELP) {
        sal_printf("Help - List all available commands\n");
    } else if (op == CLI_CMD_OP_DESC) {
        sal_printf("List all commands");
    } else {
        uint8 i;
        CLI_CMD_FUNC *pcmd = &cmds[0];
        for(i=0; i<MAX_CLI_COMMANDS; i++, pcmd++) {
            if (*pcmd) {
                char c = i < 26 ? 
                    ('a' + i) : (i < 52? ('A' + i - 26) : '0' + i - 52);
                sal_printf("  %c - ", c);
                (*(*pcmd))(CLI_CMD_OP_DESC);
                sal_printf("\n");
            }
        }
    }
}
/*查找所有已添加命令并执行命令帮助*/
APISTATIC void
APIFUNC(cli_cmd_command_help)(CLI_CMD_OP op) REENTRANT
{
    if (op == CLI_CMD_OP_HELP) {
        sal_printf("Help - Show help information for a command\n");
    } else if (op == CLI_CMD_OP_DESC) {
        sal_printf("Help for a command");
    } else {
        char cmd;
        CLI_CMD_FUNC *pcmd;

        sal_printf("Command: ");
        cmd = sal_getchar();
        sal_printf("\n");
        if (cmd >= 'a' && cmd <= 'z') {
            pcmd = &cmds[cmd - 'a'];
        } else if (cmd >= 'A' && cmd <= 'Z') {
            pcmd = &cmds[26 + cmd - 'A'];
        } else if (cmd >= '0' && cmd <= '9') {
            pcmd = &cmds[52 + cmd - '0'];
        } else if (cmd == '\r' || cmd == '\n') {
            return;
        } else {
            sal_printf("Invalid command\n");
            return;
        }
        
        if (*pcmd == NULL) {
            sal_printf("Command not available\n");
            return;
        }

        sal_printf("\n");
        (*(*pcmd))(CLI_CMD_OP_HELP);
    }
}
/*cli任务，用于跟用户交互*/
void
APIFUNC(cli)(void) REENTRANT
{
    for(;;) {
        char cmd;
        CLI_CMD_FUNC *pcmd;

        sal_printf("\n" CFG_CLI_PROMPT);//打印”CMD> ”字符串
        cmd = sal_getchar();			//获取用户输入命令
        if (cmd >= 'a' && cmd <= 'z') {
            pcmd = &cmds[cmd - 'a'];
        } else if (cmd >= 'A' && cmd <= 'Z') {
            pcmd = &cmds[26 + cmd - 'A'];
        } else if (cmd >= '0' && cmd <= '9') {
            pcmd = &cmds[52 + cmd - '0'];
        } else if (cmd == UI_KB_LF || cmd == UI_KB_ESC ||
                   cmd == UI_KB_BS || cmd == UI_KB_CR) {
            ui_backspace();
            sal_putchar('\n');
            continue;
        } else {
            sal_printf("\nInvalid command\n");
            continue;
        }
        
        if (*pcmd == NULL) {
            sal_printf("\nCommand not available\n");
            continue;
        }
		/*执行命令*/
        sal_printf(" - ");
        (*(*pcmd))(CLI_CMD_OP_DESC);
        sal_printf("\n");
        (*(*pcmd))(CLI_CMD_OP_EXEC);
    }
}
/*添加注册命令*/
BOOL
APIFUNC(cli_add_cmd)(char cmd, CLI_CMD_FUNC func) REENTRANT
{
    CLI_CMD_FUNC *pcmd = NULL;
    
    SAL_ASSERT(func);
    if (func == NULL) {
        return FALSE;
    }
    
    if (cmd >= 'a' && cmd <= 'z') {
        pcmd = &cmds[cmd - 'a'];
    } else if (cmd >= 'A' && cmd <= 'Z') {
        pcmd = &cmds[26 + cmd - 'A'];
    } else if (cmd >= '0' && cmd <= '9') {
        pcmd = &cmds[52 + cmd - '0'];
    } else {
        SAL_ASSERT(FALSE);
        return FALSE;
    }
    
    SAL_ASSERT(*pcmd == NULL);
    if (*pcmd != NULL) {
        return FALSE;
    }
    
    *pcmd = func;
    return TRUE;
}
/*移除注册命令*/
void
APIFUNC(cli_remove_cmd)(char cmd) REENTRANT
{
    CLI_CMD_FUNC *pcmd = NULL;
    
    if (cmd >= 'a' && cmd <= 'z') {
        pcmd = &cmds[cmd - 'a'];
    } else if (cmd >= 'A' && cmd <= 'Z') {
        pcmd = &cmds[26 + cmd - 'A'];
    } else if (cmd >= '0' && cmd <= '9') {
        pcmd = &cmds[52 + cmd - '0'];
    } else {
        SAL_ASSERT(FALSE);
        return;
    }
    
    *pcmd = NULL;
}
/*CLI初始化*/
void
APIFUNC(cli_init)(void) REENTRANT
{
    uint8 i;
    for(i=0; i<MAX_CLI_COMMANDS; i++) {
        cmds[i] = NULL;
    }
   	/*注册2个默认命令*/
cli_add_cmd('h', cli_cmd_list_commands);
    cli_add_cmd('H', cli_cmd_command_help);
}

#endif /* CFG_CLI_ENABLED */