WebSVN – HelenOS – Blame – //trunk/kernel/generic/src/lib/string.c

Rev	Author	Line No.	Line
4011	svoboda	1	/*
		2	* Copyright (c) 2001-2004 Jakub Jermar
		3	* All rights reserved.
		4	*
		5	* Redistribution and use in source and binary forms, with or without
		6	* modification, are permitted provided that the following conditions
		7	* are met:
		8	*
		9	* - Redistributions of source code must retain the above copyright
		10	* notice, this list of conditions and the following disclaimer.
		11	* - Redistributions in binary form must reproduce the above copyright
		12	* notice, this list of conditions and the following disclaimer in the
		13	* documentation and/or other materials provided with the distribution.
		14	* - The name of the author may not be used to endorse or promote products
		15	* derived from this software without specific prior written permission.
		16	*
		17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
		18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
		19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
		20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
		21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
		22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
		23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
		24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
		25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
		26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
		27	*/
		28
		29	/** @addtogroup generic
		30	* @{
		31	*/
		32
		33	/**
		34	* @file
		35	* @brief Miscellaneous functions.
		36	*/
		37
		38	#include <string.h>
		39	#include <print.h>
		40	#include <cpu.h>
		41	#include <arch/asm.h>
		42	#include <arch.h>
		43	#include <console/kconsole.h>
		44
		45	/** Return number of characters in a string.
		46	*
		47	* @param str NULL terminated string.
		48	*
		49	* @return Number of characters in str.
		50	*/
		51	size_t strlen(const char *str)
		52	{
		53	int i;
		54
		55	for (i = 0; str[i]; i++)
		56	;
		57
		58	return i;
		59	}
		60
		61	/** Compare two NULL terminated strings
		62	*
		63	* Do a char-by-char comparison of two NULL terminated strings.
		64	* The strings are considered equal iff they consist of the same
		65	* characters on the minimum of their lengths.
		66	*
		67	* @param src First string to compare.
		68	* @param dst Second string to compare.
		69	*
		70	* @return 0 if the strings are equal, -1 if first is smaller, 1 if second smaller.
		71	*
		72	*/
		73	int strcmp(const char src, const char dst)
		74	{
		75	for (; src && dst; src++, dst++) {
		76	if (src < dst)
		77	return -1;
		78	if (src > dst)
		79	return 1;
		80	}
		81	if (src == dst)
		82	return 0;
		83	if (!*src)
		84	return -1;
		85	return 1;
		86	}
		87
		88
		89	/** Compare two NULL terminated strings
		90	*
		91	* Do a char-by-char comparison of two NULL terminated strings.
		92	* The strings are considered equal iff they consist of the same
		93	* characters on the minimum of their lengths and specified maximal
		94	* length.
		95	*
		96	* @param src First string to compare.
		97	* @param dst Second string to compare.
		98	* @param len Maximal length for comparison.
		99	*
		100	* @return 0 if the strings are equal, -1 if first is smaller, 1 if second smaller.
		101	*
		102	*/
		103	int strncmp(const char src, const char dst, size_t len)
		104	{
		105	unsigned int i;
		106
		107	for (i = 0; (src) && (dst) && (i < len); src++, dst++, i++) {
		108	if (src < dst)
		109	return -1;
		110	if (src > dst)
		111	return 1;
		112	}
		113	if (i == len \|\| src == dst)
		114	return 0;
		115	if (!*src)
		116	return -1;
		117	return 1;
		118	}
		119
		120
		121
		122	/** Copy NULL terminated string.
		123	*
		124	* Copy at most 'len' characters from string 'src' to 'dest'.
		125	* If 'src' is shorter than 'len', '\0' is inserted behind the
		126	* last copied character.
		127	*
		128	* @param src Source string.
		129	* @param dest Destination buffer.
		130	* @param len Size of destination buffer.
		131	*/
		132	void strncpy(char dest, const char src, size_t len)
		133	{
		134	unsigned int i;
		135
		136	for (i = 0; i < len; i++) {
		137	if (!(dest[i] = src[i]))
		138	return;
		139	}
		140
		141	dest[i - 1] = '\0';
		142	}
		143
		144	/** Copy string.
		145	*
		146	* Copy string from src address to dst address. The copying is done
		147	* char-by-char until the null character. The source and destination memory
		148	* areas cannot overlap.
		149	*
		150	* @param src Source string to copy from.
		151	* @param dst Destination string to copy to.
		152	*
		153	* @return Address of the destination string.
		154	*/
		155	char strcpy(char dest, const char *src)
		156	{
		157	char *orig = dest;
		158
		159	while ((dest++ = src++) != '\0');
		160
		161	return orig;
		162	}
		163
4012	svoboda	164	/** Find first occurence of character in string.
		165	*
		166	* @param s String to search.
		167	* @param i Character to look for.
		168	*
		169	* @return Pointer to character in @a s or NULL if not found.
		170	*/
		171	extern char strchr(const char s, int i)
		172	{
		173	while (*s != '\0') {
		174	if (s == i) return (char ) s;
		175	++s;
		176	}
		177
		178	return NULL;
		179	}
		180
		181	/** Find last occurence of character in string.
		182	*
		183	* @param s String to search.
		184	* @param i Character to look for.
		185	*
		186	* @return Pointer to character in @a s or NULL if not found.
		187	*/
		188	extern char strrchr(const char s, int i)
		189	{
		190	const char *start;
		191
		192	start = s;
		193	if (*s == '\0') return NULL;
		194
		195	while (*s != '\0') ++s;
		196
		197	while (s != start) {
		198	--s;
		199	if (s == i) return (char ) s;
		200	}
		201
		202	return NULL;
		203	}
		204
4011	svoboda	205	/** @}
		206	*/

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(root)//trunk/kernel/generic/src/lib/string.c – Rev 4012