/*** *xtoa.c - convert integers/longs to ASCII string * * Copyright (c) 1989-2001, Microsoft Corporation. All rights reserved. * *Purpose: * The module has code to convert integers/longs to ASCII strings. See * *Revision History: * 06-06-89 PHG Module created, based on asm version * 03-06-90 GJF Fixed calling type, added #include and * fixed copyright. * 03-23-90 GJF Made xtoa() _CALLTYPE4. * 09-27-90 GJF New-style function declarators. * 01-21-91 GJF ANSI naming. * 04-06-93 SKS Replace _CRTAPI* with _cdecl * 01-19-96 BWT Add __int64 versions. * 09-22-97 GJF Added negation handling to x64toa. * *******************************************************************************/ #include #include #include /*** *char *_itoa, *_ltoa, *_ultoa(val, buf, radix) - convert binary int to ASCII * string * *Purpose: * Converts an int to a character string. * *Entry: * val - number to be converted (int, long or unsigned long) * int radix - base to convert into * char *buf - ptr to buffer to place result * *Exit: * fills in space pointed to by buf with string result * returns a pointer to this buffer * *Exceptions: * *******************************************************************************/ /* helper routine that does the main job. */ static void __cdecl xtoa ( unsigned long val, char *buf, unsigned radix, int is_neg ) { char *p; /* pointer to traverse string */ char *firstdig; /* pointer to first digit */ char temp; /* temp char */ unsigned digval; /* value of digit */ p = buf; if (is_neg) { /* negative, so output '-' and negate */ *p++ = '-'; val = (unsigned long)(-(long)val); } firstdig = p; /* save pointer to first digit */ do { digval = (unsigned) (val % radix); val /= radix; /* get next digit */ /* convert to ascii and store */ if (digval > 9) *p++ = (char) (digval - 10 + 'a'); /* a letter */ else *p++ = (char) (digval + '0'); /* a digit */ } while (val > 0); /* We now have the digit of the number in the buffer, but in reverse order. Thus we reverse them now. */ *p-- = '\0'; /* terminate string; p points to last digit */ do { temp = *p; *p = *firstdig; *firstdig = temp; /* swap *p and *firstdig */ --p; ++firstdig; /* advance to next two digits */ } while (firstdig < p); /* repeat until halfway */ } /* Actual functions just call conversion helper with neg flag set correctly, and return pointer to buffer. */ char * __cdecl _itoa ( int val, char *buf, int radix ) { if (radix == 10 && val < 0) xtoa((unsigned long)val, buf, radix, 1); else xtoa((unsigned long)(unsigned int)val, buf, radix, 0); return buf; } char * __cdecl _ltoa ( long val, char *buf, int radix ) { xtoa((unsigned long)val, buf, radix, (radix == 10 && val < 0)); return buf; } char * __cdecl _ultoa ( unsigned long val, char *buf, int radix ) { xtoa(val, buf, radix, 0); return buf; } #ifndef _NO_INT64 static void __stdcall x64toa ( /* stdcall is faster and smaller... Might as well use it for the helper. */ unsigned __int64 val, char *buf, unsigned radix, int is_neg ) { char *p; /* pointer to traverse string */ char *firstdig; /* pointer to first digit */ char temp; /* temp char */ unsigned digval; /* value of digit */ p = buf; if ( is_neg ) { *p++ = '-'; /* negative, so output '-' and negate */ val = (unsigned __int64)(-(__int64)val); } firstdig = p; /* save pointer to first digit */ do { digval = (unsigned) (val % radix); val /= radix; /* get next digit */ /* convert to ascii and store */ if (digval > 9) *p++ = (char) (digval - 10 + 'a'); /* a letter */ else *p++ = (char) (digval + '0'); /* a digit */ } while (val > 0); /* We now have the digit of the number in the buffer, but in reverse order. Thus we reverse them now. */ *p-- = '\0'; /* terminate string; p points to last digit */ do { temp = *p; *p = *firstdig; *firstdig = temp; /* swap *p and *firstdig */ --p; ++firstdig; /* advance to next two digits */ } while (firstdig < p); /* repeat until halfway */ } /* Actual functions just call conversion helper with neg flag set correctly, and return pointer to buffer. */ char * __cdecl _i64toa ( __int64 val, char *buf, int radix ) { x64toa((unsigned __int64)val, buf, radix, (radix == 10 && val < 0)); return buf; } char * __cdecl _ui64toa ( unsigned __int64 val, char *buf, int radix ) { x64toa(val, buf, radix, 0); return buf; } #endif /* _NO_INT64 */