source: bootcd/isolinux/syslinux-6.03/gpxe/src/core/stringextra.c

/*
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *  Copyright (C) 2004 Tobias Lorenz
 *
 *  string handling functions
 *  based on linux/lib/string.c
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

/*
 * stupid library routines.. The optimized versions should generally be found
 * as inline code in <asm-xx/string.h>
 *
 * These are buggy as well..
 *
 * * Fri Jun 25 1999, Ingo Oeser <ioe@informatik.tu-chemnitz.de>
 * -  Added strsep() which will replace strtok() soon (because strsep() is
 *    reentrant and should be faster). Use only strsep() in new code, please.
 */

/*
 * these are the standard string functions that are currently not used by
 * any code in etherboot. put into a separate file to avoid linking them in
 * with the rest of string.o
 * if anything ever does want to use a function of these, consider moving
 * the function in question back into string.c
 */
 
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>

/* *** FROM string.c *** */

#ifndef __HAVE_ARCH_STRNICMP
/**
 * strnicmp - Case insensitive, length-limited string comparison
 * @s1: One string
 * @s2: The other string
 * @len: the maximum number of characters to compare
 */
int strnicmp(const char *s1, const char *s2, size_t len)
{
        /* Yes, Virginia, it had better be unsigned */
        unsigned char c1, c2;

        c1 = 0; c2 = 0;
        if (len) {
                do {
                        c1 = *s1; c2 = *s2;
                        s1++; s2++;
                        if (!c1)
                                break;
                        if (!c2)
                                break;
                        if (c1 == c2)
                                continue;
                        c1 = tolower(c1);
                        c2 = tolower(c2);
                        if (c1 != c2)
                                break;
                } while (--len);
        }
        return (int)c1 - (int)c2;
}
#endif

char * ___strtok;

#ifndef __HAVE_ARCH_STRNCAT
/**
 * strncat - Append a length-limited, %NUL-terminated string to another
 * @dest: The string to be appended to
 * @src: The string to append to it
 * @count: The maximum numbers of bytes to copy
 *
 * Note that in contrast to strncpy, strncat ensures the result is
 * terminated.
 */
char * strncat(char *dest, const char *src, size_t count)
{
        char *tmp = dest;

        if (count) {
                while (*dest)
                        dest++;
                while ((*dest++ = *src++)) {
                        if (--count == 0) {
                                *dest = '\0';
                                break;
                        }
                }
        }

        return tmp;
}
#endif

#ifndef __HAVE_ARCH_STRSPN
/**
 * strspn - Calculate the length of the initial substring of @s which only
 *      contain letters in @accept
 * @s: The string to be searched
 * @accept: The string to search for
 */
size_t strspn(const char *s, const char *accept)
{
        const char *p;
        const char *a;
        size_t count = 0;

        for (p = s; *p != '\0'; ++p) {
                for (a = accept; *a != '\0'; ++a) {
                        if (*p == *a)
                                break;
                }
                if (*a == '\0')
                        return count;
                ++count;
        }

        return count;
}
#endif

#ifndef __HAVE_ARCH_STRCSPN
/**
 * strcspn - Calculate the length of the initial substring of @s which only
 *      contain letters not in @reject
 * @s: The string to be searched
 * @accept: The string to search for
 */
size_t strcspn(const char *s, const char *reject)
{
        const char *p;
        const char *r;
        size_t count = 0;

        for (p = s; *p != '\0'; ++p) {
                for (r = reject; *r != '\0'; ++r) {
                        if (*p == *r)
                                return count;
                }
                ++count;
        }

        return count;
}
#endif

#ifndef __HAVE_ARCH_STRPBRK
/**
 * strpbrk - Find the first occurrence of a set of characters
 * @cs: The string to be searched
 * @ct: The characters to search for
 */
char * strpbrk(const char * cs,const char * ct)
{
        const char *sc1,*sc2;

        for( sc1 = cs; *sc1 != '\0'; ++sc1) {
                for( sc2 = ct; *sc2 != '\0'; ++sc2) {
                        if (*sc1 == *sc2)
                                return (char *) sc1;
                }
        }
        return NULL;
}
#endif

#ifndef __HAVE_ARCH_STRTOK
/**
 * strtok - Split a string into tokens
 * @s: The string to be searched
 * @ct: The characters to search for
 *
 * WARNING: strtok is deprecated, use strsep instead.
 */
char * strtok(char * s,const char * ct)
{
        char *sbegin, *send;

        sbegin  = s ? s : ___strtok;
        if (!sbegin) {
                return NULL;
        }
        sbegin += strspn(sbegin,ct);
        if (*sbegin == '\0') {
                ___strtok = NULL;
                return( NULL );
        }
        send = strpbrk( sbegin, ct);
        if (send && *send != '\0')
                *send++ = '\0';
        ___strtok = send;
        return (sbegin);
}
#endif

#ifndef __HAVE_ARCH_STRSEP
/**
 * strsep - Split a string into tokens
 * @s: The string to be searched
 * @ct: The characters to search for
 *
 * strsep() updates @s to point after the token, ready for the next call.
 *
 * It returns empty tokens, too, behaving exactly like the libc function
 * of that name. In fact, it was stolen from glibc2 and de-fancy-fied.
 * Same semantics, slimmer shape. ;)
 */
char * strsep(char **s, const char *ct)
{
        char *sbegin = *s, *end;

        if (sbegin == NULL)
                return NULL;

        end = strpbrk(sbegin, ct);
        if (end)
                *end++ = '\0';
        *s = end;

        return sbegin;
}
#endif

#ifndef __HAVE_ARCH_BCOPY
/**
 * bcopy - Copy one area of memory to another
 * @src: Where to copy from
 * @dest: Where to copy to
 * @count: The size of the area.
 *
 * Note that this is the same as memcpy(), with the arguments reversed.
 * memcpy() is the standard, bcopy() is a legacy BSD function.
 *
 * You should not use this function to access IO space, use memcpy_toio()
 * or memcpy_fromio() instead.
 */
char * bcopy(const char * src, char * dest, int count)
{
        return memmove(dest,src,count);
}
#endif

#ifndef __HAVE_ARCH_MEMSCAN
/**
 * memscan - Find a character in an area of memory.
 * @addr: The memory area
 * @c: The byte to search for
 * @size: The size of the area.
 *
 * returns the address of the first occurrence of @c, or 1 byte past
 * the area if @c is not found
 */
void * memscan(const void * addr, int c, size_t size)
{
        unsigned char * p = (unsigned char *) addr;

        while (size) {
                if (*p == c)
                        return (void *) p;
                p++;
                size--;
        }
        return (void *) p;
}
#endif