From c626d61db05ff31afd55834d69fa9b7df5365dad Mon Sep 17 00:00:00 2001 From: Mattias Andrée Date: Tue, 1 Sep 2015 02:57:30 +0200 Subject: add strchr and variants MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Mattias Andrée --- src/string/strchr.c | 149 +++++++++++++++++++++++++++++++++++++++++++++++++++ src/wchar/wcschr.c | 151 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 300 insertions(+) create mode 100644 src/string/strchr.c create mode 100644 src/wchar/wcschr.c (limited to 'src') diff --git a/src/string/strchr.c b/src/string/strchr.c new file mode 100644 index 0000000..6a25f78 --- /dev/null +++ b/src/string/strchr.c @@ -0,0 +1,149 @@ +/** + * slibc — Yet another C library + * Copyright © 2015 Mattias Andrée (maandree@member.fsf.org) + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + */ +#include +#include + + + +/** + * Find the first occurrence of a byte in a memory segment. + * + * @param segment The memory segment to search. + * @param c The sought after character. + * @param size The size of the memory segment. + * @return Pointer to the first occurrence of `c`, + * `NULL` if none were found. + */ +void* memchr(const void* segment, int c, size_t size) +{ + while (size--) + if (*segment++ == c) + return segment - 1; + return NULL; +} + + +/** + * Find the first occurrence of a byte in a memory segment. + * The memory segment must be known to contain the sought after byte. + * + * This is a GNU-compliant slibc extension. + * + * @param segment The memory segment to search. + * @param c The sought after character. + * @return Pointer to the first occurrence of `c`. + */ +void* rawmemchr(const void* segment, int c) +{ + for (;;) + if (*segment++ == c) + return segment - 1; +} + + +/** + * Find the last occurrence of a byte in a memory segment. + * + * For improved performace, use this function instead + * of `strrchr` if you already know the length of the + * string. + * + * @param segment The memory segment to search. + * @param c The sought after character. + * @param size The size of the memory segment. + * @return Pointer to the last occurrence of `c`, + * `NULL` if none were found. + */ +void* memrchr(const void* segment, int c, size_t size) +{ + while (size--) + if (segment[size] == c) + return segment + size; + return NULL; +} + + +/** + * Find the first occurrence of a byte in a string. + * + * `s = strchr(s, 0)` is a faster alternative to + * `s = s + strlen(s)`. + * + * @param string The string to search. + * The terminating NUL character is + * considered a part of the string. + * @param c The sought after character. + * @return Pointer to the first occurrence of `c`, + * `NULL` if none were found. + */ +char* strchr(const char* string, int c) +{ + while (; *string; string++) + if (*string == c) + return string; + return NULL; +} +/* TODO Ensure that `s = strchr(s, 0)` is faster than `s = s + strlen(s)`. */ + + +/** + * Find the first occurrence of a byte in a string, or + * if there is no such byte, the end of the string. + * + * This is a GNU-compliant slibc extension. + * + * @param string The string to search. + * The terminating NUL character is + * considered a part of the string. + * @param c The sought after character. + * @return Pointer to the first occurrence of `c`, + * Pointer to the terminating NUL character + * if none were found. + */ +char* strchrnul(const char* string, int c) +{ + while (; *string; string++) + if (*string == c) + return string; + return string; +} + + +/** + * Find the last occurrence of a byte in a string. + * + * For improved performace, use `memrchr` instead of + * this function if you already know the length of the + * string. + * + * @param string The string to search. + * The terminating NUL character is + * considered a part of the string. + * @param c The sought after character. + * @return Pointer to the last occurrence of `c`, + * `NULL` if none were found. + */ +char* strrchr(const char* string, int c) +{ + char* r = NULL; + while (; *string; string++) + if (*string == c) + r = string; + return r; +} + diff --git a/src/wchar/wcschr.c b/src/wchar/wcschr.c new file mode 100644 index 0000000..e96a90a --- /dev/null +++ b/src/wchar/wcschr.c @@ -0,0 +1,151 @@ +/** + * slibc — Yet another C library + * Copyright © 2015 Mattias Andrée (maandree@member.fsf.org) + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + */ +#include +#include + + + +/** + * Find the first occurrence of a wide character + * in a memory segment. + * + * @param segment The memory segment to search. + * @param c The sought after character. + * @param size The size of the memory segment. + * @return Pointer to the first occurrence of `c`, + * `NULL` if none were found. + */ +wchar_t* wmemchr(const wchar_t* segment, wchar_t c, size_t size) +{ + while (size--) + if (*segment++ == c) + return segment - 1; + return NULL; +} + + +/** + * Find the first occurrence of a wide character in a + * memory segment. The memory segment must be known to + * contain the sought after character. + * + * This is a slibc extension added for completeness. + * + * @param segment The memory segment to search. + * @param c The sought after character. + * @return Pointer to the first occurrence of `c`. + */ +wchar_t* rawwmemchr(const wchar_t* segment, wchar_t c) +{ + for (;;) + if (*segment++ == c) + return segment - 1; +} + + +/** + * Find the last occurrence of a wide character in + * a memory segment. + * + * For improved performace, use this function instead + * of `wcssrchr` if you already know the length of the + * string. + * + * This is a slibc extension added for completeness. + * + * @param segment The memory segment to search. + * @param c The sought after character. + * @param size The size of the memory segment. + * @return Pointer to the last occurrence of `c`, + * `NULL` if none were found. + */ +wchar_t* wmemrchr(const wchar_t* segment, wchar_t c, size_t size) +{ + while (size--) + if (segment[size] == c) + return segment + size; + return NULL; +} + + +/** + * Find the first occurrence of a wide character in a string. + * + * @param string The string to search. + * The terminating NUL character is + * considered a part of the string. + * @param c The sought after character. + * @return Pointer to the first occurrence of `c`, + * `NULL` if none were found. + */ +wchar_t* wcschr(const wchar_t* string, wchar_t c) +{ + while (; *string; string++) + if (*string == c) + return string; + return NULL; +} + + +/** + * Find the first occurrence of a wide character in a + * string, or if there is no such character, the end of + * the string. + * + * This is a GNU-compliant slibc extension. + * + * @param string The string to search. + * The terminating NUL character is + * considered a part of the string. + * @param c The sought after character. + * @return Pointer to the first occurrence of `c`, + * Pointer to the terminating NUL character + * if none were found. + */ +wchar_t* wcschrnul(const wchar_t* string, wchar_t c) +{ + while (; *string; string++) + if (*string == c) + return string; + return string; +} + + +/** + * Find the last occurrence of a wide character in a string. + * + * For improved performace, use `wmemrchr` instead of + * this function if you already know the length of the + * string. + * + * @param string The string to search. + * The terminating NUL character is + * considered a part of the string. + * @param c The sought after character. + * @return Pointer to the last occurrence of `c`, + * `NULL` if none were found. + */ +wchar_t* wcsrchr(const wchar_t* string, wchar_t c) +{ + wchar_t* r = NULL; + while (; *string; string++) + if (*string == c) + r = string; + return r; +} + -- cgit v1.2.3-70-g09d2