source: trunk/packages/xen-3.1/xen-3.1/xen/common/string.c @ 34

/*
 *  linux/lib/string.c
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 */

#include <xen/types.h>
#include <xen/string.h>
#include <xen/ctype.h>

#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

#ifndef __HAVE_ARCH_STRLCPY
/**
 * strlcpy - Copy a %NUL terminated string into a sized buffer
 * @dest: Where to copy the string to
 * @src: Where to copy the string from
 * @size: size of destination buffer
 *
 * Compatible with *BSD: the result is always a valid
 * NUL-terminated string that fits in the buffer (unless,
 * of course, the buffer size is zero). It does not pad
 * out the result like strncpy() does.
 */
size_t strlcpy(char *dest, const char *src, size_t size)
{
        size_t ret = strlen(src);

        if (size) {
                size_t len = (ret >= size) ? size-1 : ret;
                memcpy(dest, src, len);
                dest[len] = '\0';
        }
        return ret;
}
EXPORT_SYMBOL(strlcpy);
#endif

#ifndef __HAVE_ARCH_STRLCAT
/**
 * strlcat - Append a %NUL terminated string into a sized buffer
 * @dest: Where to copy the string to
 * @src: Where to copy the string from
 * @size: size of destination buffer
 *
 * Compatible with *BSD: the result is always a valid
 * NUL-terminated string that fits in the buffer (unless,
 * of course, the buffer size is zero).
 */
size_t strlcat(char *dest, const char *src, size_t size)
{
        size_t slen = strlen(src);
        size_t dlen = strnlen(dest, size);
        char *p = dest + dlen;

        while ((p - dest) < size)
                if ((*p++ = *src++) == '\0')
                        break;

        if (dlen < size)
                *(p-1) = '\0';

        return slen + dlen;
}
EXPORT_SYMBOL(strlcat);
#endif

#ifndef __HAVE_ARCH_STRCMP
/**
 * strcmp - Compare two strings
 * @cs: One string
 * @ct: Another string
 */
int strcmp(const char * cs,const char * ct)
{
        register signed char __res;

        while (1) {
                if ((__res = *cs - *ct++) != 0 || !*cs++)
                        break;
        }

        return __res;
}
#endif

#ifndef __HAVE_ARCH_STRNCMP
/**
 * strncmp - Compare two length-limited strings
 * @cs: One string
 * @ct: Another string
 * @count: The maximum number of bytes to compare
 */
int strncmp(const char * cs,const char * ct,size_t count)
{
        register signed char __res = 0;

        while (count) {
                if ((__res = *cs - *ct++) != 0 || !*cs++)
                        break;
                count--;
        }

        return __res;
}
#endif

#ifndef __HAVE_ARCH_STRCHR
/**
 * strchr - Find the first occurrence of a character in a string
 * @s: The string to be searched
 * @c: The character to search for
 */
char * strchr(const char * s, int c)
{
        for(; *s != (char) c; ++s)
                if (*s == '\0')
                        return NULL;
        return (char *) s;
}
#endif

#ifndef __HAVE_ARCH_STRRCHR
/**
 * strrchr - Find the last occurrence of a character in a string
 * @s: The string to be searched
 * @c: The character to search for
 */
char * strrchr(const char * s, int c)
{
       const char *p = s + strlen(s);
       do {
           if (*p == (char)c)
               return (char *)p;
       } while (--p >= s);
       return NULL;
}
#endif

#ifndef __HAVE_ARCH_STRLEN
/**
 * strlen - Find the length of a string
 * @s: The string to be sized
 */
size_t strlen(const char * s)
{
        const char *sc;

        for (sc = s; *sc != '\0'; ++sc)
                /* nothing */;
        return sc - s;
}
#endif

#ifndef __HAVE_ARCH_STRNLEN
/**
 * strnlen - Find the length of a length-limited string
 * @s: The string to be sized
 * @count: The maximum number of bytes to search
 */
size_t strnlen(const char * s, size_t count)
{
        const char *sc;

        for (sc = s; count-- && *sc != '\0'; ++sc)
                /* nothing */;
        return sc - s;
}
#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_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_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_MEMSET
/**
 * memset - Fill a region of memory with the given value
 * @s: Pointer to the start of the area.
 * @c: The byte to fill the area with
 * @count: The size of the area.
 *
 * Do not use memset() to access IO space, use memset_io() instead.
 */
void * memset(void * s,int c,size_t count)
{
        char *xs = (char *) s;

        while (count--)
                *xs++ = c;

        return s;
}
#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)
{
        char *tmp = dest;

        while (count--)
                *tmp++ = *src++;

        return dest;
}
#endif

#ifndef __HAVE_ARCH_MEMCPY
/**
 * memcpy - Copy one area of memory to another
 * @dest: Where to copy to
 * @src: Where to copy from
 * @count: The size of the area.
 *
 * You should not use this function to access IO space, use memcpy_toio()
 * or memcpy_fromio() instead.
 */
void * memcpy(void * dest,const void *src,size_t count)
{
        char *tmp = (char *) dest, *s = (char *) src;

        while (count--)
                *tmp++ = *s++;

        return dest;
}
#endif

#ifndef __HAVE_ARCH_MEMMOVE
/**
 * memmove - Copy one area of memory to another
 * @dest: Where to copy to
 * @src: Where to copy from
 * @count: The size of the area.
 *
 * Unlike memcpy(), memmove() copes with overlapping areas.
 */
void * memmove(void * dest,const void *src,size_t count)
{
        char *tmp, *s;

        if (dest <= src) {
                tmp = (char *) dest;
                s = (char *) src;
                while (count--)
                        *tmp++ = *s++;
                }
        else {
                tmp = (char *) dest + count;
                s = (char *) src + count;
                while (count--)
                        *--tmp = *--s;
                }

        return dest;
}
#endif

#ifndef __HAVE_ARCH_MEMCMP
/**
 * memcmp - Compare two areas of memory
 * @cs: One area of memory
 * @ct: Another area of memory
 * @count: The size of the area.
 */
int memcmp(const void * cs,const void * ct,size_t count)
{
        const unsigned char *su1, *su2;
        int res = 0;

        for( su1 = cs, su2 = ct; 0 < count; ++su1, ++su2, count--)
                if ((res = *su1 - *su2) != 0)
                        break;
        return res;
}
#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(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

#ifndef __HAVE_ARCH_STRSTR
/**
 * strstr - Find the first substring in a %NUL terminated string
 * @s1: The string to be searched
 * @s2: The string to search for
 */
char * strstr(const char * s1,const char * s2)
{
        int l1, l2;

        l2 = strlen(s2);
        if (!l2)
                return (char *) s1;
        l1 = strlen(s1);
        while (l1 >= l2) {
                l1--;
                if (!memcmp(s1,s2,l2))
                        return (char *) s1;
                s1++;
        }
        return NULL;
}
#endif

#ifndef __HAVE_ARCH_MEMCHR
/**
 * memchr - Find a character in an area of memory.
 * @s: The memory area
 * @c: The byte to search for
 * @n: The size of the area.
 *
 * returns the address of the first occurrence of @c, or %NULL
 * if @c is not found
 */
void *memchr(const void *s, int c, size_t n)
{
        const unsigned char *p = s;
        while (n-- != 0) {
                if ((unsigned char)c == *p++) {
                        return (void *)(p-1);
                }
        }
        return NULL;
}

#endif

/*
 * Local variables:
 * mode: C
 * c-set-style: "BSD"
 * c-basic-offset: 8
 * tab-width: 8
 * indent-tabs-mode: t
 * End:
 */