/*
 * Copyright (c) 1996 The Regents of the University of California.
 * All rights reserved.
 *
 * Permission to use, copy, modify, and distribute this software and its
 * documentation for any purpose, without fee, and without written agreement
 * is hereby granted, provided that the above copyright notice and the
 * following two paragraphs appear in all copies of this software.
 *
 * IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR
 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING
 * OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF THE
 * UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
 * ON AN "AS IS" BASIS, AND THE UNIVERSITY OF CALIFORNIA HAS NO OBLIGATION TO
 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
 *
 * $Id: snprintf.c,v 1.3 1996/08/31 02:53:37 aswan Exp $
 *
 * This is stolen directly from Patrick Powell (papowell@sdsu.edu)
 * It was originally posted to the bugtraq mailing list...
 */


static void dopr();
static char *end, *etext, *edata;

#include <sys/types.h>
/* varargs declarations: */

#if defined(HAVE_STDARG_H)
# include <stdarg.h>
# define HAVE_STDARGS    /* let's hope that works everywhere (mj) */
# define VA_LOCAL_DECL   va_list ap;
# define VA_START(f)     va_start(ap, f)
# define VA_SHIFT(v,t)  ;   /* no-op for ANSI */
# define VA_END          va_end(ap)
#else
# if defined(HAVE_VARARGS_H)
#  include <varargs.h>
#  undef HAVE_STDARGS
#  define VA_LOCAL_DECL   va_list ap;
#  define VA_START(f)     va_start(ap)      /* f is ignored! */
#  define VA_SHIFT(v,t) v = va_arg(ap,t)
#  define VA_END        va_end(ap)
# else
XX ** NO VARARGS ** XX
# endif
#endif

int vsnprintf(str, count, fmt, args)
	char *str;
	size_t count;
	const char *fmt;
	va_list args;
{
	str[0] = 0;
	end = str+count-1;
	dopr( str, fmt, args );
	if( count>0 ){
		end[0] = 0;
	}
	return(strlen(str));
}

/* VARARGS3 */
#ifdef HAVE_STDARGS
int snprintf (char *str,size_t count,const char *fmt,...)
#else
int snprintf (va_alist) va_dcl
#endif
{
#ifndef HAVE_STDARGS
    char *str;
	size_t count;
    char *fmt;
#endif
    VA_LOCAL_DECL

    VA_START (fmt);
    VA_SHIFT (str, char *);
    VA_SHIFT (count, size_t );
    VA_SHIFT (fmt, char *);
    (void) vsnprintf ( str, count, fmt, ap);
    VA_END;
	return( strlen( str ) );
}

/*
 * dopr(): poor man's version of doprintf
 */

static void fmtstr(  char *value, int ljust, int len, int zpad );
static void fmtnum(  long value, int base, int dosign,
	int ljust, int len, int zpad );
static void dostr( char * );
static char *output;
static void dopr_outch( int c );

static void dopr( buffer, format, args )
	char *buffer;
	char *format;
	va_list args;
{
	int ch;
	long value;
	int longflag = 0;
	char *strvalue;
	int ljust;
	int len;
	int prec;
	int zpad;

	output = buffer;
	while( (ch = *format++) ){
		prec = 0;
		len = 0;
		switch( ch ){
		case '%':
			ljust = len = zpad = 0;
		nextch: 
			ch = *format++;
			switch( ch ){
			case 0:
				dostr( "**end of format**" );
				return;
			case '-': ljust = 1; goto nextch;
			case '0': /* set zero padding if len not set */
				if(len==0) zpad = '0';
			case '1': case '2': case '3':
			case '4': case '5': case '6':
			case '7': case '8': case '9':
				len = len*10 + ch - '0';
				goto nextch;
			case 'l': longflag = 1; goto nextch;
			case 'u': case 'U':
				/*fmtnum(value,base,dosign,ljust,len,zpad) */
				if( longflag ){
					value = va_arg( args, long );
				} else {
					value = va_arg( args, int );
				}
				fmtnum( value, 10,0, ljust, len, zpad ); break;
			case 'o': case 'O':
				/*fmtnum(value,base,dosign,ljust,len,zpad) */
				if( longflag ){
					value = va_arg( args, long );
				} else {
					value = va_arg( args, int );
				}
				fmtnum( value, 8,0, ljust, len, zpad ); break;
			case 'd': case 'D':
				if( longflag ){
					value = va_arg( args, long );
				} else {
					value = va_arg( args, int );
				}
				fmtnum( value, 10,1, ljust, len, zpad ); break;
			case 'x':
				if( longflag ){
					value = va_arg( args, long );
				} else {
					value = va_arg( args, int );
				}
				fmtnum( value, 16,0, ljust, len, zpad ); break;
			case 'X':
				if( longflag ){
					value = va_arg( args, long );
				} else {
					value = va_arg( args, int );
				}
				fmtnum( value,-16,0, ljust, len, zpad ); break;
			case 's':
				strvalue = va_arg( args, char *);
				fmtstr( strvalue,ljust,len,zpad ); break;
			case 'c':
				ch = va_arg( args, int );
				dopr_outch( ch ); break;
			case '*':
				len = va_arg( args, int);
				goto nextch;
			case '.':
				ch = *format++;
				if (ch == '*') {
					prec = va_arg( args, int);
				} else {
					int n;
					while (isdigit(ch)) {
						n = n*10 + ch - '0';
						ch = *format++;
					}
					prec = n < 0 ? -1 : n;
				}
				goto nextch;
			case '%': dopr_outch( ch ); continue;
			default:
				dostr(  "???????" );
			}
			longflag = 0;
			break;
		default:
			dopr_outch( ch );
			break;
		}
	}
	*output = 0;
}

static void
fmtstr(  value, ljust, len, zpad )
	char *value;
	int ljust, len, zpad;
{
	int padlen, strlen;	/* amount to pad */

	if (value < (char *)0x1000)	/* check for possibly memory fault conditions */
		return;
	if( value == 0 ){
		value = "";
	}
	for( strlen = 0; value[strlen] ; strlen++ ); /* strlen */
	padlen = len - strlen;
	if( padlen < 0 ) padlen = 0;
	if( ljust ) padlen = -padlen;
	while( padlen > 0 ) {
		dopr_outch( ' ' );
		--padlen;
	}
	dostr( value );
	while( padlen < 0 ) {
		dopr_outch( ' ' );
		++padlen;
	}
}

static void
fmtnum(  value, base, dosign, ljust, len, zpad )
	long value;
	int base, dosign, ljust, len, zpad;
{
	int signvalue = 0;
	unsigned long uvalue;
	char convert[20];
	int place = 0;
	int padlen = 0;	/* amount to pad */
	int caps = 0;

	/* DEBUGP(("value 0x%x, base %d, dosign %d, ljust %d, len %d, zpad %d\n",
		value, base, dosign, ljust, len, zpad )); */
	uvalue = value;
	if( dosign ){
		if( value < 0 ) {
			signvalue = '-';
			uvalue = -value; 
		}
	}
	if( base < 0 ){
		caps = 1;
		base = -base;
	}
	do{
		convert[place++] =
			(caps? "0123456789ABCDEF":"0123456789abcdef")
			 [uvalue % (unsigned)base  ];
		uvalue = (uvalue / (unsigned)base );
	}while(uvalue);
	convert[place] = 0;
	padlen = len - place;
	if( padlen < 0 ) padlen = 0;
	if( ljust ) padlen = -padlen;
	/* DEBUGP(( "str '%s', place %d, sign %c, padlen %d\n",
		convert,place,signvalue,padlen)); */
	if( zpad && padlen > 0 ){
		if( signvalue ){
			dopr_outch( signvalue );
			--padlen;
			signvalue = 0;
		}
		while( padlen > 0 ){
			dopr_outch( zpad );
			--padlen;
		}
	}
	while( padlen > 0 ) {
		dopr_outch( ' ' );
		--padlen;
	}
	if( signvalue ) dopr_outch( signvalue );
	while( place > 0 ) dopr_outch( convert[--place] );
	while( padlen < 0 ){
		dopr_outch( ' ' );
		++padlen;
	}
}

static void dostr( str )
	char *str;
{
	while(*str) dopr_outch(*str++);
}

static void dopr_outch( c )
	int c;
{
	c = c & 0xff;
	if( iscntrl(c) && !isspace(c)) {
		c = '@' + (c & 0x1F);
		if( end == 0 || output < end ){
			*output++ = '^';
		}
	}
	if( end == 0 || output < end ){
		*output++ = c;
	}
}