l64a.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/* Copyright (c) 1984 AT&T */
/* All Rights Reserved */
#pragma ident "%Z%%M% %I% %E% SMI" /* from S5R2 1.5 */
/*LINTLIBRARY*/
/*
* convert long int to base 64 ascii
* char set is [./0-9A-Za-z]
* two's complement negatives are assumed,
* but no assumptions are made about sign propagation on right shift
*
*/
#include <values.h>
#define BITSPERCHAR 6 /* to hold entire character set */
#define BITSPERLONG (BITSPERBYTE * sizeof(long))
#define NMAX ((BITSPERLONG + BITSPERCHAR - 1)/BITSPERCHAR)
#define SIGN (-(1L << (BITSPERLONG - BITSPERCHAR - 1)))
#define CHARMASK ((1 << BITSPERCHAR) - 1)
#define WORDMASK ((1L << ((NMAX - 1) * BITSPERCHAR)) - 1)
static char buf[NMAX + 1];
char *
l64a(lg)
register long lg;
{
register char *s = buf;
while (lg != 0) {
register int c = ((int)lg & CHARMASK) + ('0' - 2);
if (c > '9')
c += 'A' - '9' - 1;
if (c > 'Z')
c += 'a' - 'Z' - 1;
*s++ = c;
/* fill high-order CHAR if negative */
/* but suppress sign propagation */
lg = ((lg < 0) ? (lg >> BITSPERCHAR) | SIGN :
lg >> BITSPERCHAR) & WORDMASK;
}
*s = '\0';
return (buf);
}