FoenixMCP/src/cli/cli.c

/**
 * Implementation of the command line interface
 */

#include <ctype.h>
#include <string.h>
#include "log.h"
#include "types.h"
#include "syscalls.h"
#include "cli/cli.h"
#include "cli/dos_cmds.h"

#define MAX_COMMAND_SIZE    128
#define MAX_ARGC            32

//
// Types
//

// Structure to hold a record about a command...

typedef struct s_cli_command {
    char *name;
    char *help;
    cli_cmd_handler handler;
} t_cli_command, *p_cli_command;

/*
 * Commands
 */

 extern const t_cli_command g_cli_commands[];

 //
 // List all the commands
 //
 int cmd_help(short channel, int argc, char * argv[]) {
     p_cli_command command;

     for (command = g_cli_commands; (command != 0) && (command->name != 0); command++) {
         sys_chan_write(channel, command->help, strlen(command->help));
         sys_chan_write(channel, "\n", 2);
     }
     return 0;
 }

//
// CLI variables
//

const t_cli_command g_cli_commands[] = {
    { "?", "? -- print this helpful message", cmd_help },
    { "HELP", "HELP -- print this helpful message", cmd_help },
    { "DIR", "DIR <path> -- print directory listing", cmd_dir },
    { "LOAD", "LOAD <path> -- load a file into memory", cmd_load },
    { "TYPE", "TYPE <path> -- print the contents of a text file", cmd_type },
    { 0, 0 }
};

//
// Attempt to execute a command
//
// Inputs:
//  command = the upper case name of the command (first word of the command line)
//  parameters = the string of parameters to be passed to the command
//
short cli_exec(short channel, char * command, int argc, char * argv[]) {
    const char * cmd_not_found = "Command not found.\n";
    p_cli_command commands = g_cli_commands;

    log3(LOG_INFO, "cli_exec: '", argv[0], "'");
    log_num(LOG_INFO, "argc = ", argc);

    while ((commands != 0) && (commands->name != 0)) {
        // Does the command match the name?
        if (strcmp(commands->name, command) == 0) {
            // Found it, execute the handler
            return commands->handler(channel, argc, argv);
        } else {
            // No match, keep checking...
            commands++;
        }
    }

    // Built in command not found..
    // TODO: search the current drive for an executable file
    sys_chan_write(channel, cmd_not_found, strlen(cmd_not_found));
    return -1;
}

char * strtok_r(char * source, const char * delimiter, char ** saveptr) {
    char * x = *saveptr;
    char * y;

    /* Skip over leading delimiters */
    for (x = *saveptr; *x && (*x == delimiter[0]); x++) {

    }

    /* If we reached the end of the string, return NULL */
    if (*x == 0) {
        return 0;
    }

    for (y = x; *y && (*y != delimiter[0]); y++) {

    }

    /* If we reached the end of the string, return x */
    if (*y == 0) {
        *saveptr = y;
        return x;
    }

    /* Otherwise, make that position in the source string NULL, and return x */
    *y = 0;
    *saveptr = y + 1;
    return x;
}

//
// Enter the CLI's read-eval-print loop
//
short cli_repl(short channel) {
    char command_line[MAX_COMMAND_SIZE];
    char * arg;
    char * token_save;
    char * delim = " ";
    int argc = 0;
    char * argv[MAX_ARGC];

    const char * welcome = "\n\nFoenix/MCP Command Line Utility... online.\nType \"HELP\" or \"?\" for help.\n\n";
    sys_chan_write(channel, welcome, strlen(welcome));

    while (1) {
        sys_chan_write(channel, "\n> ", 3);                           // Print our prompt
        sys_chan_readline(channel, command_line, MAX_COMMAND_SIZE);   // Attempt to read line
        sys_chan_write(channel, "\n", 1);

        for (argc = 0, token_save = command_line; argc < MAX_ARGC; argc++) {
            arg = strtok_r(command_line, delim, &token_save);
            if (arg != 0) {
                argv[argc] = arg;
            } else {
                break;
            }
        }

        if (argc > 0) {
            int i;
            for (i = 0; i < strlen(argv[0]); i++) {
                argv[0][i] = toupper(argv[0][i]);
            }

            // Try to execute the command
            cli_exec(channel, argv[0], argc, argv);
        }
    }

    return 0;
}

//
// Initialize the CLI
//
// Returns:
//  0 on success, negative number on error
//
short cli_init() {
    return 0;
}