From 5278f6def4248391a481382bd7b0042b04c829f2 Mon Sep 17 00:00:00 2001 From: Richard Qin Date: Tue, 21 Apr 2026 23:16:50 +0800 Subject: feat: add string manipulation functions derived from musl libc This commit introduces a variety of string manipulation functions, including: - `memmem`: Searches for a substring in a memory area. - `memmove`: Safely copies memory areas, handling overlaps. - `mempcpy`: Copies memory and returns a pointer to the end of the destination. - `memrchr`: Finds the last occurrence of a character in a memory area. - `memset`: Fills a memory area with a specified value. - `rindex`: Returns the last occurrence of a character in a string. - `stpcpy` and `stpncpy`: Copies strings and returns a pointer to the end. - `strcat`, `strchr`, `strcspn`, `strlcat`, `strlcpy`, `strlen`, `strncat`, `strncmp`, `strncpy`, `strnlen`, `strpbrk`, `strrchr`, `strstr`, `strtok`, and `strtok_r`: Various string manipulation functions for concatenation, searching, and tokenization. Assembly implementations for `memcpy`, `memmove`, and `memset` are also included for optimized performance on x86_64 architectures. --- na/lib/string/strncmp.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) create mode 100644 na/lib/string/strncmp.c (limited to 'na/lib/string/strncmp.c') diff --git a/na/lib/string/strncmp.c b/na/lib/string/strncmp.c new file mode 100644 index 0000000..b98473b --- /dev/null +++ b/na/lib/string/strncmp.c @@ -0,0 +1,12 @@ +/* SPDX-License-Identifier: MIT */ +/* Derived from musl libc (Copyright © 2005-2020 Rich Felker, et al.) */ + +#include + +int strncmp(const char *_l, const char *_r, size_t n) +{ + const unsigned char *l=(void *)_l, *r=(void *)_r; + if (!n--) return 0; + for (; *l && *r && n && *l == *r ; l++, r++, n--); + return *l - *r; +} -- cgit v1.2.3