source: bootcd/isolinux/syslinux-6.03/gpxe/src/hci/shell.c

/*
 * Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

FILE_LICENCE ( GPL2_OR_LATER );

#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>
#include <readline/readline.h>
#include <gpxe/command.h>
#include <gpxe/shell.h>

/** @file
 *
 * Minimal command shell
 *
 */

/** The shell prompt string */
static const char shell_prompt[] = "gPXE> ";

/** Flag set in order to exit shell */
static int exit_flag = 0;

/** "exit" command body */
static int exit_exec ( int argc, char **argv __unused ) {

        if ( argc == 1 ) {
                exit_flag = 1;
        } else {
                printf ( "Usage: exit\n"
                         "Exits the command shell\n" );
        }

        return 0;
}

/** "exit" command definition */
struct command exit_command __command = {
        .name = "exit",
        .exec = exit_exec,
};

/** "help" command body */
static int help_exec ( int argc __unused, char **argv __unused ) {
        struct command *command;
        unsigned int hpos = 0;

        printf ( "\nAvailable commands:\n\n" );
        for_each_table_entry ( command, COMMANDS ) {
                hpos += printf ( "  %s", command->name );
                if ( hpos > ( 16 * 4 ) ) {
                        printf ( "\n" );
                        hpos = 0;
                } else {
                        while ( hpos % 16 ) {
                                printf ( " " );
                                hpos++;
                        }
                }
        }
        printf ( "\n\nType \"<command> --help\" for further information\n\n" );
        return 0;
}

/** "help" command definition */
struct command help_command __command = {
        .name = "help",
        .exec = help_exec,
};

/**
 * Start command shell
 *
 */
void shell ( void ) {
        char *line;

        exit_flag = 0;
        while ( ! exit_flag ) {
                line = readline ( shell_prompt );
                if ( line ) {
                        system ( line );
                        free ( line );
                }
        }
}