WebSVN – HelenOS – Blame – /trunk/boot/generic/string.c/

Rev	Author	Line No.	Line
1881	jermar	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	#include <string.h>
		34
		35	/**
		36	* @file
		37	* @brief String manipulation functions.
		38	*/
		39
		40	/** Return number of characters in a string.
		41	*
		42	* @param str NULL terminated string.
		43	*
		44	* @return Number of characters in str.
		45	*/
		46	size_t strlen(const char *str)
		47	{
		48	int i;
		49
		50	for (i = 0; str[i]; i++)
		51	;
		52
		53	return i;
		54	}
		55
		56	/** Compare two NULL terminated strings
		57	*
		58	* Do a char-by-char comparison of two NULL terminated strings.
		59	* The strings are considered equal iff they consist of the same
1896	jermar	60	* characters on the minimum of their lengths.
		61	*
		62	* @param src First string to compare.
		63	* @param dst Second string to compare.
		64	*
		65	* @return 0 if the strings are equal, -1 if first is smaller, 1 if second smaller.
		66	*
		67	*/
		68	int strcmp(const char src, const char dst)
		69	{
		70	for (; src && dst; src++, dst++) {
		71	if (src < dst)
		72	return -1;
		73	if (src > dst)
		74	return 1;
		75	}
		76	if (src == dst)
		77	return 0;
		78	if (!*src)
		79	return -1;
		80	return 1;
		81	}
		82
		83
		84	/** Compare two NULL terminated strings
		85	*
		86	* Do a char-by-char comparison of two NULL terminated strings.
		87	* The strings are considered equal iff they consist of the same
1881	jermar	88	* characters on the minimum of their lengths and specified maximal
		89	* length.
		90	*
		91	* @param src First string to compare.
		92	* @param dst Second string to compare.
		93	* @param len Maximal length for comparison.
		94	*
		95	* @return 0 if the strings are equal, -1 if first is smaller, 1 if second smaller.
		96	*
		97	*/
		98	int strncmp(const char src, const char dst, size_t len)
		99	{
		100	int i;
		101
1896	jermar	102	for (i = 0; src && dst && i < len; src++, dst++, i++) {
1881	jermar	103	if (src < dst)
		104	return -1;
		105	if (src > dst)
		106	return 1;
		107	}
		108	if (i == len \|\| src == dst)
		109	return 0;
		110	if (!*src)
		111	return -1;
		112	return 1;
		113	}
		114
		115	/** Copy NULL terminated string.
		116	*
		117	* Copy at most 'len' characters from string 'src' to 'dest'.
		118	* If 'src' is shorter than 'len', '\0' is inserted behind the
		119	* last copied character.
		120	*
		121	* @param src Source string.
		122	* @param dest Destination buffer.
		123	* @param len Size of destination buffer.
		124	*/
		125	void strncpy(char dest, const char src, size_t len)
		126	{
		127	int i;
		128	for (i = 0; i < len; i++) {
		129	if (!(dest[i] = src[i]))
		130	return;
		131	}
		132	dest[i-1] = '\0';
		133	}
		134
		135	/** Convert ascii representation to unative_t
		136	*
		137	* Supports 0x for hexa & 0 for octal notation.
		138	* Does not check for overflows, does not support negative numbers
		139	*
		140	* @param text Textual representation of number
		141	* @return Converted number or 0 if no valid number ofund
		142	*/
		143	unative_t atoi(const char *text)
		144	{
		145	int base = 10;
		146	unative_t result = 0;
		147
		148	if (text[0] == '0' && text[1] == 'x') {
		149	base = 16;
		150	text += 2;
		151	} else if (text[0] == '0')
		152	base = 8;
		153
		154	while (*text) {
		155	if (base != 16 && \
		156	((text >= 'A' && text <= 'F' )
		157	\|\| (text >='a' && text <='f')))
		158	break;
		159	if (base == 8 && *text >='8')
		160	break;
		161
		162	if (text >= '0' && text <= '9') {
		163	result *= base;
		164	result += *text - '0';
		165	} else if (text >= 'A' && text <= 'F') {
		166	result *= base;
		167	result += *text - 'A' + 10;
		168	} else if (text >= 'a' && text <= 'f') {
		169	result *= base;
		170	result += *text - 'a' + 10;
		171	} else
		172	break;
		173	text++;
		174	}
		175
		176	return result;
		177	}
		178
		179	/** @}
		180	*/

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