path: root/lib/string.c

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

/*
 * 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.
 */
 
#include <linux/types.h>
#include <linux/string.h>
#include <linux/ctype.h>

#ifndef __HAVE_ARCH_STRNICMP
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 = NULL;

#ifndef __HAVE_ARCH_STRCPY
char * strcpy(char * dest,const char *src)
{
	char *tmp = dest;

	while ((*dest++ = *src++) != '\0')
		/* nothing */;
	return tmp;
}
#endif

#ifndef __HAVE_ARCH_STRNCPY
char * strncpy(char * dest,const char *src,size_t count)
{
	char *tmp = dest;

	while (count-- && (*dest++ = *src++) != '\0')
		/* nothing */;

	return tmp;
}
#endif

#ifndef __HAVE_ARCH_STRCAT
char * strcat(char * dest, const char * src)
{
	char *tmp = dest;

	while (*dest)
		dest++;
	while ((*dest++ = *src++) != '\0')
		;

	return tmp;
}
#endif

#ifndef __HAVE_ARCH_STRNCAT
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_STRCMP
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
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
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
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
size_t strlen(const char * s)
{
	const char *sc;

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

#ifndef __HAVE_ARCH_STRNLEN
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
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
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
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

char * strsep(char **s, const char * ct)
{
	char *sbegin=*s;
	if (!sbegin) 
		return NULL;
	
	sbegin += strspn(sbegin,ct);
	if (*sbegin == '\0') 
		return NULL;
	
	*s = strpbrk( sbegin, ct);
	if (*s && **s != '\0')
		**s++ = '\0';
	return (sbegin);
}
#endif

#ifndef __HAVE_ARCH_MEMSET
void * memset(void * s, int c, size_t count)
{
	char *xs = (char *) s;

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

	return s;
}
#endif

#ifndef __HAVE_ARCH_BCOPY
char * bcopy(const char * src, char * dest, int count)
{
	char *tmp = dest;

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

	return dest;
}
#endif

#ifndef __HAVE_ARCH_MEMCPY
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
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
int memcmp(const void * cs,const void * ct,size_t count)
{
	const unsigned char *su1, *su2;
	signed char res = 0;

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

/*
 * find the first occurrence of byte 'c', or 1 past the area if none
 */
#ifndef __HAVE_ARCH_MEMSCAN
void * memscan(void * addr, int c, size_t size)
{
	unsigned char * p = (unsigned char *) addr;
	unsigned char * e = p + size;

	while (p != e) {
		if (*p == c)
			return (void *) p;
		p++;
	}

	return (void *) p;
}
#endif

#ifndef __HAVE_ARCH_STRSTR
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