libproff/vsnprintf.c

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DEFINITIONS

This source file includes following functions.
  1. VA_START
  2. snprintf
  3. vsnprintf
  4. dopr
  5. fmtstr
  6. fmtnum
  7. dostr
  8. dopr_outch

#include "config.h"
#include "libproff.h"

#include "vsnprintf.h"

/*
**  SNPRINTF, VSNPRINT -- counted versions of printf
**
**      These versions have been grabbed off the net.  They have been
**      cleaned up to compile properly and support for .precision and
**      %lx has been added.
*/

#ifndef HAVE_SNPRINTF

/**************************************************************
 * 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...
 *
 * 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 nasty effects.
 **************************************************************/

/*static char _id[] = "$Id: vsnprintf.c,v 1.1.1.1 1998/07/29 15:14:28 proff Exp $";*/

# include <stdarg.h>

# define VA_LOCAL_DECL  va_list ap;
# define VA_START(f)    va_start(ap, f)
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# define VA_END         va_end(ap)
EXPORT int snprintf(char *str, size_t count, const char *fmt, ...)
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{
        int len;
        VA_LOCAL_DECL

        VA_START(fmt);
        len = vsnprintf(str, count, fmt, ap);
        VA_END;
        return len;
}
#endif /* !HAVE_SNPRINTF */

#ifndef HAVE_VSNPRINTF
static void dopr();
static char *end;
static int      SnprfOverflow;
EXPORT int vsnprintf(char *str, size_t count, const char *fmt, va_list args)
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{
        str[0] = 0;
        end = str + count - 1;
        SnprfOverflow = 0;
        dopr( str, fmt, args );
        if (count > 0)
                end[0] = 0;
#if 0
        if (SnprfOverflow && tTd(57, 2))
                printf("\nvsnprintf overflow, len = %d, str = %s",
                        count, shortenstring(str, 203));
#endif
        return strlen(str);
}

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

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

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

       output = buffer;
       while( (ch = *format++) ){
               switch( ch ){
               case '%':
                       ljust = len = zpad = maxwidth = 0;
                       longflag = pointflag = 0;
               nextch:
                       ch = *format++;
                       switch( ch ){
                       case 0:
                               dostr( "**end of format**" , 0);
                               return;
                       case '-': ljust = 1; goto nextch;
                       case '0': /* set zero padding if len not set */
                               if(len==0 && !pointflag) zpad = '0';
                       case '1': case '2': case '3':
                       case '4': case '5': case '6':
                       case '7': case '8': case '9':
                               if (pointflag)
                                 maxwidth = maxwidth*10 + ch - '0';
                               else
                                 len = len*10 + ch - '0';
                               goto nextch;
                       case '*': 
                               if (pointflag)
                                 maxwidth = va_arg( args, int );
                               else
                                 len = va_arg( args, int );
                               goto nextch;
                       case '.': pointflag = 1; 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 *);
                               if (maxwidth > 0 || !pointflag) {
                                 if (pointflag && len > maxwidth)
                                   len = maxwidth; /* Adjust padding */
                                 fmtstr( strvalue,ljust,len,zpad, maxwidth);
                               }
                               break;
                       case 'c':
                               ch = va_arg( args, int );
                               dopr_outch( ch ); break;
                       case '%': dopr_outch( ch ); continue;
                       default:
                               dostr(  "???????" , 0);
                       }
                       break;
               default:
                       dopr_outch( ch );
                       break;
               }
       }
       *output = 0;
}

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

       if( value == 0 ){
               value = "<NULL>";
       }
       for( strlen = 0; value[strlen]; ++ strlen ); /* strlen */
       if (strlen > maxwidth && maxwidth)
         strlen = maxwidth;
       padlen = len - strlen;
       if( padlen < 0 ) padlen = 0;
       if( ljust ) padlen = -padlen;
       while( padlen > 0 ) {
               dopr_outch( ' ' );
               --padlen;
       }
       dostr( value, maxwidth );
       while( padlen < 0 ) {
               dopr_outch( ' ' );
               ++padlen;
       }
}

static void
fmtnum(  value, base, dosign, ljust, len, zpad )
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       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 , cut)
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     char *str;
     int cut;
{
  if (cut) {
    while(*str && cut-- > 0) dopr_outch(*str++);
  } else {
    while(*str) dopr_outch(*str++);
  }
}

static void
dopr_outch( c )
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       int c;
{
#if 0
       if( iscntrl(c) && c != '\n' && c != '\t' ){
               c = '@' + (c & 0x1F);
               if( end == 0 || output < end )
                       *output++ = '^';
       }
#endif
       if( end == 0 || output < end )
               *output++ = c;
       else
                SnprfOverflow++;
}

#endif /* !HAVE_VSNPRINTF */

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