sane-project-backends/lib/snprintf.c

#include "../include/sane/config.h"

#ifndef HAVE_SNPRINTF

/***************************************************************************
 * LPRng - An Extended Print Spooler System
 *
 * Copyright 1988-1997, Patrick Powell, San Diego, CA
 *     papowell@sdsu.edu
 * See below for conditions of use.
 *
 ***************************************************************************
 * MODULE: snprintf.c
 * PURPOSE: LPRng version of printf - absolutely bombproof (hopefully!)
 **************************************************************************/
#if 0

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				The End
#include "lp.h"
#endif

#include <stdarg.h>
#include <errno.h>
#include <sys/types.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)

/**** ENDINCLUDE ****/

static char *const _id = "$Id$";

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

static char * plp_Errormsg ( int err );
static void dopr( char *buffer, const char *format, va_list args );
static void fmtstr(  char *value, int ljust, int len, int zpad, int precision );
static void fmtnum(  long value, int base, int dosign,
	int ljust, int len, int zpad, int precision );
static void fmtdouble( int fmt, double value,
	int ljust, int len, int zpad, int precision );
static void dostr( char * );
static char *output;
static void dopr_outch( int c );
static char *end;
int visible_control = 1;

/**************************************************************
 * Original:
 * Patrick Powell Tue Apr 11 09:48:21 PDT 1995
 * A bombproof version of doprnt (dopr) included.
 * Sigh.  This sort of thing is always nasty do deal with.  Note that
 * the version here does not include floating point...
 *
 * plp_snprintf() is used instead of sprintf() as it does limit checks
 * for string length.  This covers a nasty loophole.
 *
 * The other functions are there to prevent NULL pointers from
 * causing nast effects.
 **************************************************************/

int vsnprintf(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 ) );
}

static void dopr( char *buffer, const char *format, va_list args )
{
	int ch;
	long value;
	int longflag = 0;
	char *strvalue;
	int ljust;
	int len;
	int zpad;
	int precision;
	int set_precision;
	double dval;
	int err = errno;

	output = buffer;
	while( (ch = *format++) ){
		switch( ch ){
		case '%':
			ljust = len = zpad = 0;
			precision = -1; set_precision = 0;
		nextch: 
			ch = *format++;
			switch( ch ){
			case 0:
				dostr( "**end of format**" );
				return;
			case '-': ljust = 1; goto nextch;
			case '.': set_precision = 1; precision = 0; goto nextch;
			case '*': len = va_arg( args, int ); goto nextch;
			case '0': /* set zero padding if len not set */
				if(len==0 && set_precision == 0 ) zpad = '0';
			case '1': case '2': case '3':
			case '4': case '5': case '6':
			case '7': case '8': case '9':
				if( set_precision ){
					precision = precision*10 + ch - '0';
				} else {
					len = len*10 + ch - '0';
				}
				goto nextch;
			case 'l': longflag = 1; goto nextch;
			case 'u': case 'U':
				/*fmtnum(value,base,dosign,ljust,len, zpad, precision) */
				if( longflag ){
					value = va_arg( args, long );
				} else {
					value = va_arg( args, int );
				}
				fmtnum( value, 10,0, ljust, len, zpad, precision ); break;
			case 'o': case 'O':
				/*fmtnum(value,base,dosign,ljust,len, zpad, precision) */
				if( longflag ){
					value = va_arg( args, long );
				} else {
					value = va_arg( args, int );
				}
				fmtnum( value, 8,0, ljust, len, zpad, precision ); 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, precision ); break;
			case 'x':
				if( longflag ){
					value = va_arg( args, long );
				} else {
					value = va_arg( args, int );
				}
				fmtnum( value, 16,0, ljust, len, zpad, precision ); break;
			case 'X':
				if( longflag ){
					value = va_arg( args, long );
				} else {
					value = va_arg( args, int );
				}
				fmtnum( value,-16,0, ljust, len, zpad, precision ); break;
			case 's':
				strvalue = va_arg( args, char *);
				fmtstr( strvalue,ljust,len, zpad, precision );
				break;
			case 'c':
				ch = va_arg( args, int );
				{ char b[2];
					int vsb = visible_control;
					b[0] = ch;
					b[1] = 0;
					visible_control = 0;
					fmtstr( b,ljust,len, zpad, precision );
					visible_control = vsb;
				}
				break;
			case 'f': case 'g':
				dval = va_arg( args, double );
				fmtdouble( ch, dval,ljust,len, zpad, precision ); break;
			case 'm':
				fmtstr( plp_Errormsg(err),ljust,len, zpad, precision ); break;
			case '%': dopr_outch( ch ); continue;
			default:
				dostr(  "???????" );
			}
			longflag = 0;
			break;
		default:
			dopr_outch( ch );
			break;
		}
	}
	*output = 0;
}

/*
 * Format '%[-]len[.precision]s'
 * -   = left justify (ljust)
 * len = minimum length
 * precision = numbers of chars in string to use
 */
static void
fmtstr(  char *value, int ljust, int len, int zpad, int precision )
{
	int padlen, strlen, i, c;	/* amount to pad */

	if( value == 0 ){
		value = "<NULL>";
	}
	if( precision > 0 ){
		strlen = precision;
	} else {
		/* cheap strlen so you do not have library call */
		for( strlen = 0; (c=value[strlen]); ++ strlen ){
			if( visible_control && iscntrl( c ) && !isspace( c ) ){
				++strlen;
			}
		}
	}
	padlen = len - strlen;
	if( padlen < 0 ) padlen = 0;
	if( ljust ) padlen = -padlen;
	while( padlen > 0 ) {
		dopr_outch( ' ' );
		--padlen;
	}
	/* output characters */
	for( i = 0; (c = value[i]); ++i ){
		if( visible_control && iscntrl( c ) && !isspace( c ) ){
			dopr_outch('^');
			c = ('@' | (c & 0x1F));
		}
		dopr_outch(c);
	}
	while( padlen < 0 ) {
		dopr_outch( ' ' );
		++padlen;
	}
}

static void
fmtnum(  long value, int base, int dosign, int ljust,
	int len, int zpad, int precision )
{
	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
fmtdouble( int fmt, double value, int ljust, int len, int zpad, int precision )
{
	char convert[128];
	char fmtstr[128];
	int l;

	if( len == 0 ) len = 10;
	if( len > sizeof(convert) - 10 ){
		len = sizeof(convert) - 10;
	}
	if( precision > sizeof(convert) - 10 ){
		precision = sizeof(convert) - 10;
	}
	if( precision > len ) precision = len;
	strcpy( fmtstr, "%" );
	if( ljust ) strcat(fmtstr, "-" );
	if( len ){
		sprintf( fmtstr+strlen(fmtstr), "%d", len );
	}
	if( precision > 0 ){
		sprintf( fmtstr+strlen(fmtstr), ".%d", precision );
	}
	l = strlen( fmtstr );
	fmtstr[l] = fmt;
	fmtstr[l+1] = 0;
	sprintf( convert, fmtstr, value );
	dostr( convert );
}

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

static void dopr_outch( int c )
{
	if( end == 0 || output < end ){
		*output++ = c;
	}
}


/****************************************************************************
 * static char *plp_errormsg( int err )
 *  returns a printable form of the
 *  errormessage corresponding to the valie of err.
 *  This is the poor man's version of sperror(), not available on all systems
 *  Patrick Powell Tue Apr 11 08:05:05 PDT 1995
 ****************************************************************************/
/****************************************************************************/
#if !defined(HAVE_STRERROR)

# if defined(HAVE_SYS_NERR)
#  if !defined(HAVE_SYS_NERR_DEF)
     extern int sys_nerr;
#  endif
#  define num_errors    (sys_nerr)
# else
#  define num_errors    (-1)            /* always use "errno=%d" */
# endif

# if defined(HAVE_SYS_ERRLIST)
#  if !defined(HAVE_SYS_ERRLIST_DEF)
     extern const char *const sys_errlist[];
#  endif
# else
#  undef  num_errors
#  define num_errors   (-1)            /* always use "errno=%d" */
# endif

#endif

static char * plp_Errormsg ( int err )
{
    char *cp;

#if defined(HAVE_STRERROR)
	cp = (void *)strerror(err);
#else
# if defined(HAVE_SYS_ERRLIST)
    if (err >= 0 && err < num_errors) {
		cp = (void *)sys_errlist[err];
    } else
# endif
	{
		static char msgbuf[32];     /* holds "errno=%d". */
		/* SAFE use of sprintf */
		(void) sprintf (msgbuf, "errno=%d", err);
		cp = msgbuf;
    }
#endif
    return (cp);
}

#if defined(TEST)
#include <stdio.h>
int main( void )
{
	char buffer[128];
	char *t;
	char *test1 = "01234";
	errno = 1;
	plp_snprintf( buffer, sizeof(buffer), (t="errno '%m'")); printf( "%s = '%s'\n", t, buffer );
	plp_snprintf( buffer, sizeof(buffer), (t = "%s"), test1 ); printf( "%s = '%s'\n", t, buffer );
	plp_snprintf( buffer, sizeof(buffer), (t = "%12s"), test1 ); printf( "%s = '%s'\n", t, buffer );
	plp_snprintf( buffer, sizeof(buffer), (t = "%-12s"), test1 ); printf( "%s = '%s'\n", t, buffer );
	plp_snprintf( buffer, sizeof(buffer), (t = "%12.2s"), test1 ); printf( "%s = '%s'\n", t, buffer );
	plp_snprintf( buffer, sizeof(buffer), (t = "%-12.2s"), test1 ); printf( "%s = '%s'\n", t, buffer );
	plp_snprintf( buffer, sizeof(buffer), (t = "%g"), 1.25 ); printf( "%s = '%s'\n", t, buffer );
	plp_snprintf( buffer, sizeof(buffer), (t = "%g"), 1.2345 ); printf( "%s = '%s'\n", t, buffer );
	plp_snprintf( buffer, sizeof(buffer), (t = "%12g"), 1.25 ); printf( "%s = '%s'\n", t, buffer );
	plp_snprintf( buffer, sizeof(buffer), (t = "%12.2g"), 1.25 ); printf( "%s = '%s'\n", t, buffer );
	plp_snprintf( buffer, sizeof(buffer), (t = "%0*d"), 6, 1 ); printf( "%s = '%s'\n", t, buffer );
	return(0);
}
#endif


#endif /* HAVE_SNPRINTF */