minix/commands/aal/long2str.c

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2005-04-21 16:53:53 +02:00
/* $Header$ */
/*
* (c) copyright 1987 by the Vrije Universiteit, Amsterdam, The Netherlands.
* See the copyright notice in the ACK home directory, in the file "Copyright".
*/
/* Integer to String translator
-> base is a value from [-16,-2] V [2,16]
-> base < 0: see 'val' as unsigned value
-> no checks for buffer overflow and illegal parameters
(1985, EHB)
*/
#define MAXWIDTH 32
char *
long2str(val, base)
register long val;
register base;
{
static char numbuf[MAXWIDTH];
static char vec[] = "0123456789ABCDEF";
register char *p = &numbuf[MAXWIDTH];
int sign = (base > 0);
*--p = '\0'; /* null-terminate string */
if (val) {
if (base > 0) {
if (val < 0L) {
long v1 = -val;
if (v1 == val)
goto overflow;
val = v1;
}
else
sign = 0;
}
else
if (base < 0) { /* unsigned */
base = -base;
if (val < 0L) { /* taken from Amoeba src */
register mod, i;
overflow:
mod = 0;
for (i = 0; i < 8 * sizeof val; i++) {
mod <<= 1;
if (val < 0)
mod++;
val <<= 1;
if (mod >= base) {
mod -= base;
val++;
}
}
*--p = vec[mod];
}
}
do {
*--p = vec[(int) (val % base)];
val /= base;
} while (val != 0L);
if (sign)
*--p = '-'; /* don't forget it !! */
}
else
*--p = '0'; /* just a simple 0 */
return p;
}