xnu-792.6.22.tar.gz

[apple/xnu.git] / osfmk / device / subrs.c

/*
 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * The contents of this file constitute Original Code as defined in and
 * are subject to the Apple Public Source License Version 1.1 (the
 * "License").  You may not use this file except in compliance with the
 * License.  Please obtain a copy of the License at
 * http://www.apple.com/publicsource and read it before using this file.
 * 
 * This Original Code and all software distributed under the License are
 * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
 * License for the specific language governing rights and limitations
 * under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/*
 * @OSF_COPYRIGHT@
 */
/*
 *(C)UNIX System Laboratories, Inc. all or some portions of this file are
 *derived from material licensed to the University of California by
 *American Telephone and Telegraph Co. or UNIX System Laboratories,
 *Inc. and are reproduced herein with the permission of UNIX System
 *Laboratories, Inc.
 */

/* 
 * Mach Operating System
 * Copyright (c) 1993,1991,1990,1989,1988 Carnegie Mellon University
 * All Rights Reserved.
 * 
 * Permission to use, copy, modify and distribute this software and its
 * documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation.
 * 
 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 * 
 * Carnegie Mellon requests users of this software to return to
 * 
 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
 *  School of Computer Science
 *  Carnegie Mellon University
 *  Pittsburgh PA 15213-3890
 * 
 * any improvements or extensions that they make and grant Carnegie Mellon
 * the rights to redistribute these changes.
 */
/*
 */
/*
 * Copyright (c) 1988 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */
/*
 * Random device subroutines and stubs.
 */

#include <vm/vm_kern.h>
#include <kern/misc_protos.h>

/* String routines, from CMU */
#ifdef	strcpy
#undef strcmp
#undef strncmp
#undef strcpy
#undef strncpy
#undef strlen
#endif

/*
 * Abstract:
 *      strcmp (s1, s2) compares the strings "s1" and "s2".
 *      It returns 0 if the strings are identical. It returns
 *      > 0 if the first character that differs in the two strings
 *      is larger in s1 than in s2 or if s1 is longer than s2 and
 *      the contents are identical up to the length of s2.
 *      It returns < 0 if the first differing character is smaller
 *      in s1 than in s2 or if s1 is shorter than s2 and the
 *      contents are identical upto the length of s1.
 */

int
strcmp(
        register const char *s1,
        register const char *s2)
{
        register unsigned int a, b;

        do {
                a = *s1++;
                b = *s2++;
                if (a != b)
                        return a-b;     /* includes case when
                                           'a' is zero and 'b' is not zero
                                           or vice versa */
	} while (a != '\0');

        return 0;       /* both are zero */
}

/*
 * Abstract:
 *      strncmp (s1, s2, n) compares the strings "s1" and "s2"
 *      in exactly the same way as strcmp does.  Except the
 *      comparison runs for at most "n" characters.
 */

int
strncmp(
        register const char *s1,
        register const char *s2,
        size_t n)
{
        register unsigned int a, b;

        while (n != 0) {
                a = *s1++;
                b = *s2++;
                if (a != b)
                        return a-b;     /* includes case when
                                           'a' is zero and 'b' is not zero
                                           or vice versa */
                if (a == '\0')
                        return 0;       /* both are zero */
                n--;
	}

        return 0;
}


//
// Lame implementation just for use by strcasecmp/strncasecmp
//
static int
tolower(unsigned char ch)
{
    if (ch >= 'A' && ch <= 'Z')
	ch = 'a' + (ch - 'A');

    return ch;
}

int
strcasecmp(const char *s1, const char *s2)
{
    const unsigned char *us1 = (const u_char *)s1,
                 *us2 = (const u_char *)s2;

    while (tolower(*us1) == tolower(*us2++))
	if (*us1++ == '\0')
	    return (0);
    return (tolower(*us1) - tolower(*--us2));
}

int
strncasecmp(const char *s1, const char *s2, size_t n)
{
    if (n != 0) {
	const unsigned char *us1 = (const u_char *)s1,
                     *us2 = (const u_char *)s2;

	do {
	    if (tolower(*us1) != tolower(*us2++))
		return (tolower(*us1) - tolower(*--us2));
	    if (*us1++ == '\0')
		break;
	} while (--n != 0);
    }
    return (0);
}


/*
 * Abstract:
 *      strcpy copies the contents of the string "from" including
 *      the null terminator to the string "to". A pointer to "to"
 *      is returned.
 */

char *
strcpy(
        register char *to,
        register const char *from)
{
        register char *ret = to;

        while ((*to++ = *from++) != '\0')
                continue;

        return ret;
}


/*
 * Abstract:
 *      strncpy copies "count" characters from the "from" string to
 *      the "to" string. If "from" contains less than "count" characters
 *      "to" will be padded with null characters until exactly "count"
 *      characters have been written. The return value is a pointer
 *      to the "to" string.
 */

char *
strncpy(
	char *s1, 
	const char *s2,
	size_t n)
{
        char *os1 = s1;
        unsigned long i;

        for (i = 0; i < n;)
                if ((*s1++ = *s2++) == '\0')
                        for (i++; i < n; i++)
                                *s1++ = '\0';
                else
                        i++;
        return (os1);
}

/*
 * atoi:
 *
 *      This function converts an ascii string into an integer.
 *
 * input        : string
 * output       : a number
 */

int
atoi(
	u_char  *cp)
{
        int     number;

        for (number = 0; ('0' <= *cp) && (*cp <= '9'); cp++)
                number = (number * 10) + (*cp - '0');

        return( number );
}

/*
 * convert an ASCII string (decimal radix) to an integer
 * inputs:
 *	p	string pointer.
 *	t	char **, return a pointer to the cahr which terminates the
 *		numeric string.
 * returns:
 *	integer value of the numeric string.
 * side effect:
 *	pointer to terminating char.
 */

int
atoi_term(
	char	*p,	/* IN */
	char	**t)	/* OUT */
{
        register int n;
        register int f;

        n = 0;
        f = 0;
        for(;;p++) {
                switch(*p) {
                case ' ':
                case '\t':
                        continue;
                case '-':
                        f++;
                case '+':
                        p++;
                }
                break;
        }
        while(*p >= '0' && *p <= '9')
                n = n*10 + *p++ - '0';

        /* return pointer to terminating character */
        if ( t )
                *t = p;

        return(f? -n: n);
}

/*
 * convert an integer to an ASCII string.
 * inputs:
 *	num	integer to be converted
 *	str	string pointer.
 *
 * outputs:
 *	pointer to string start.
 */

char *
itoa(
	int	num,
	char	*str)
{
        char    digits[11];
        register char *dp;
        register char *cp = str;

        if (num == 0) {
            *cp++ = '0';
        }
        else {
            dp = digits;
            while (num) {
                *dp++ = '0' + num % 10;
                num /= 10;
            }
            while (dp != digits) {
                *cp++ = *--dp;
            }
        }
        *cp++ = '\0';

	return str;
}

char *
strcat(
	register char *dest,
	register const char *src)
{
	char *old = dest;

	while (*dest)
		++dest;
	while (*dest++ = *src++)
		;
	return (old);
}