[syslinux] NEW: COM32 module to alias

[Gene Cumm]

From: Gene Cumm <gene.cumm at gmail.com>

alias.c: A simple COM32 module that allows the creation of an alias
within the config for SYSLINUX, etc.

Signed-off-by: Gene Cumm <gene.cumm at gmail.com>

---

If, for example, you had two labels that only differed by the length
of the label (a short name) or additional APPENDd parameters, this
would reduce the amount of copies of the same configuration.

LABEL boot1
KERNEL kernel
APPEND initrd=initrd.img

LABEL boot2
KERNEL kernel
APPEND initrd=initrd.img extraParamForBoot2

could be shortened to

LABEL boot1
KERNEL kernel
APPEND initrd=initrd.img

LABEL boot2
KERNEL alias.c32
APPEND boot1 extraParamForBoot2

I created this as I've got several instances of both short names and
extra APPENDd parameters in a config file I use.  The only thing that
would be better (if this benefits others) would be an ALIAS option in
the config file.

com32/modules/alias.c:

/* ----------------------------------------------------------------------- *
 *
 *   Copyright 2008 Gene Cumm - All Rights Reserved
 *
 *   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, Inc., 53 Temple Place Ste 330,
 *   Boston MA 02111-1307, USA; either version 2 of the License, or
 *   (at your option) any later version; incorporated herein by reference.
 *
 * ----------------------------------------------------------------------- */

/*
 * alias.c
 *
 * Alias COM32 application;  Call as a KERNEL with a boot line command as the
 * APPEND line.
 */

/*
 * History
 * b002	Alter the concatenation of the command line arguments to use memcpy
 * b001	Initial version
 */

#include <stdio.h>
#include <stdlib.h>
// #include <stdbool.h>
#include <string.h>

#ifdef __COM32__		/* Allow targetting Linux, etc to test */
#include <syslinux/boot.h>	/* syslinux_run_command() */
#endif	/* __COM32__ */

#define ALIAS_CMD_SZ	128

// #define DO_DEBUG 1

#define APP_LONGNAME	"Alias COM32"
#define APP_NAME	"alias"
#define APP_YEAR	"2008"
#define APP_AUTHOR	"Gene Cumm"
#define APP_VER		"beta-b002"

int main(int argc, char *argv[]){
	char cmdstr[ALIAS_CMD_SZ];	// Command string to execute
	int curpos;	// Current position in cmdstr; Use memcpy rather than strcat
	int arglen;	// length of current argument string
	int i;

	// Initialization
	curpos = 0;
	cmdstr[0] = 0;
	for(i=1; i<argc; i++){
		arglen = strlen(argv[i]);
		memcpy(cmdstr + curpos, argv[i], arglen);
		curpos += arglen;
		cmdstr[curpos] = ' ';
		curpos += 1;
		cmdstr[curpos] = 0;
	}
	curpos -= 1;
	cmdstr[curpos] = 0;
#ifdef DO_DEBUG
	printf("Parsed arg list\n");
#endif
	printf("--alias: '%s'\n", cmdstr);
#ifdef __COM32__
	syslinux_run_command(cmdstr);
#endif	/* __COM32__ */

	return 0;
}