Annotation of prex/sys/lib/string.c, Revision 1.1
1.1 ! nbrk 1: /*-
! 2: * Copyright (c) 2005-2006, Kohsuke Ohtani
! 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: * 1. Redistributions of source code must retain the above copyright
! 9: * notice, this list of conditions and the following disclaimer.
! 10: * 2. Redistributions in binary form must reproduce the above copyright
! 11: * notice, this list of conditions and the following disclaimer in the
! 12: * documentation and/or other materials provided with the distribution.
! 13: * 3. Neither the name of the author nor the names of any co-contributors
! 14: * may be used to endorse or promote products derived from this software
! 15: * without specific prior written permission.
! 16: *
! 17: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
! 18: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
! 19: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
! 20: * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
! 21: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
! 22: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
! 23: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
! 24: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
! 25: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
! 26: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
! 27: * SUCH DAMAGE.
! 28: */
! 29:
! 30: /*
! 31: * string.c - Minimum string library for kernel
! 32: */
! 33:
! 34: #include <sys/types.h>
! 35: #include <kernel.h>
! 36:
! 37: /*
! 38: * Safer version of strncpy
! 39: * The destination string is always terminated with NULL character.
! 40: */
! 41: size_t
! 42: strlcpy(char *dest, const char *src, size_t count)
! 43: {
! 44: char *d = dest;
! 45: const char *s = src;
! 46: size_t n = count;
! 47:
! 48: /* Copy as many bytes as will fit */
! 49: if (n != 0 && --n != 0) {
! 50: do {
! 51: if ((*d++ = *s++) == 0)
! 52: break;
! 53: } while (--n != 0);
! 54: }
! 55:
! 56: /* Not enough room in dst, add NUL and traverse rest of src */
! 57: if (n == 0) {
! 58: if (count != 0)
! 59: *d = '\0'; /* NUL-terminate dst */
! 60: while (*s++)
! 61: ;
! 62: }
! 63:
! 64: return (size_t)(s - src - 1); /* count does not include NUL */
! 65: }
! 66:
! 67: int
! 68: strncmp(const char *src, const char *tgt, size_t count)
! 69: {
! 70: signed char res = 0;
! 71:
! 72: while (count) {
! 73: if ((res = *src - *tgt++) != 0 || !*src++)
! 74: break;
! 75: count--;
! 76: }
! 77: return res;
! 78: }
! 79:
! 80: /* The returned size does not include the last NULL char */
! 81: size_t
! 82: strnlen(const char *str, size_t count)
! 83: {
! 84: const char *tmp;
! 85:
! 86: for (tmp = str; count-- && *tmp != '\0'; ++tmp);
! 87: return (size_t)(tmp - str);
! 88: }
! 89:
! 90: void *
! 91: memcpy(void *dest, const void *src, size_t count)
! 92: {
! 93: char *tmp = (char *)dest, *s = (char *)src;
! 94:
! 95: while (count--)
! 96: *tmp++ = *s++;
! 97:
! 98: return dest;
! 99: }
! 100:
! 101: void *
! 102: memset(void *dest, int ch, size_t count)
! 103: {
! 104: char *p = (char *)dest;
! 105:
! 106: while (count--)
! 107: *p++ = (char)ch;
! 108:
! 109: return dest;
! 110: }
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