From 8c5afdb1601a1864e9fd0416b9d2f42d0bdf489a Mon Sep 17 00:00:00 2001 From: Ian Moffett Date: Wed, 19 Jun 2024 22:16:26 -0400 Subject: kernel: lib: Add strncmp() Signed-off-by: Ian Moffett --- sys/include/lib/string.h | 1 + sys/lib/string/strncmp.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 51 insertions(+) create mode 100644 sys/lib/string/strncmp.c diff --git a/sys/include/lib/string.h b/sys/include/lib/string.h index 3ae33ea..8500af2 100644 --- a/sys/include/lib/string.h +++ b/sys/include/lib/string.h @@ -44,5 +44,6 @@ int memcmp(const void *s1, const void *s2, size_t n); void *memset(void *s, int c, size_t n); int strcmp(const char *s1, const char *s2); +int strncmp(const char *s1, const char *s2, size_t n); #endif /* !_LIB_STRING_H_ */ diff --git a/sys/lib/string/strncmp.c b/sys/lib/string/strncmp.c new file mode 100644 index 0000000..b68fa58 --- /dev/null +++ b/sys/lib/string/strncmp.c @@ -0,0 +1,50 @@ +/* + * Copyright (c) 2023-2024 Ian Marco Moffett and the Osmora Team. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of Hyra nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +#include + +int +strncmp(const char *s1, const char *s2, size_t n) +{ + if (n == 0) { + return 0; + } + + do { + if (*s1 != *s2++) { + return (*(unsigned char *)s1 - *(unsigned char *)--s2); + } + + if (*s1++ == 0) { + break; + } + } while (--n != 0); + + return 0; +} -- cgit v1.2.3