/**
* 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 <http://www.gnu.org/licenses/>.
*/
#include <string.h>
#include <strings.h>
#include <stdint.h>
#include <ctype.h>
/**
* Compare two memory segments alphabetically in a case sensitive manner.
*
* @param a A negative value is returned if this is the lesser.
* @param b A positive value is returned if this is the lesser.
* @param size The size of the segments.
* @return Zero is returned if `a` and `b` are equal, otherwise,
* see the specifications for `a` and `b`.
*/
int memcmp(const void* a, const void* b, size_t size)
{
const signed char* s1 = a;
const signed char* s2 = b;
while (size--)
if (*s1 == *s2)
s1++, s2++;
else
return (int)(*s1 - *s2);
return 0;
}
/**
* Compare two memory segments alphabetically in a case insensitive manner.
*
* This is a slibc extension added because it was useful
* in implementing slibc itself.
*
* @param a A negative value is returned if this is the lesser.
* @param b A positive value is returned if this is the lesser.
* @param size The size of the segments.
* @return Zero is returned if `a` and `b` are equal, otherwise,
* see the specifications for `a` and `b`.
*/
int memcasecmp(const void* a, const void* b, size_t size)
{
const signed char* s1 = a;
const signed char* s2 = b;
int c1, c2;
for (; size--; s1++, s2++)
if (*s1 != *s2)
{
c1 = isalpha(*s1) ? tolower(*s1) : (int)*s1;
c2 = isalpha(*s2) ? tolower(*s2) : (int)*s2;
if ((c1 -= c2))
return c1;
}
return 0;
}
/**
* Compare two strings alphabetically in a case sensitive manner.
*
* @param a A negative value is returned if this is the lesser.
* @param b A positive value is returned if this is the lesser.
* @return Zero is returned if `a` and `b` are equal, otherwise,
* see the specifications for `a` and `b`.
*/
int strcmp(const char* a, const char* b)
{
size_t n = strlen(a);
size_t m = strlen(b);
return memcmp(a, b, (n < m ? n : m) + 1);
}
/**
* Compare two strings alphabetically in a case insensitive manner.
* Be aware, only ASCII characters are case insensitive, non-ASCII
* characters are case sensitive.
*
* @param a A negative value is returned if this is the lesser.
* @param b A positive value is returned if this is the lesser.
* @return Zero is returned if `a` and `b` are equal, otherwise,
* see the specifications for `a` and `b`.
*/
int strcasecmp(const char* a, const char* b)
{
return strncasecmp(a, b, SIZE_MAX);
}
/**
* Compare two strings alphabetically in a case sensitive manner.
*
* @param a A negative value is returned if this is the lesser.
* @param b A positive value is returned if this is the lesser.
* @param length The maximum number of characters to compare.
* @return Zero is returned if `a` and `b` are equal, otherwise,
* see the specifications for `a` and `b`.
*/
int strncmp(const char* a, const char* b, size_t length)
{
size_t n = strnlen(a, length);
size_t m = strnlen(b, length);
int r = memcmp(a, b, (n < m ? n : m));
return r ? r : n == m ? 0 : n < m ? -1 : +1;
}
/**
* Compare two strings alphabetically in a case insensitive manner.
* Be aware, only ASCII characters are case insensitive, non-ASCII
* characters are case sensitive.
*
* @param a A negative value is returned if this is the lesser.
* @param b A positive value is returned if this is the lesser.
* @param length The maximum number of characters to compare.
* @return Zero is returned if `a` and `b` are equal, otherwise,
* see the specifications for `a` and `b`.
*/
int strncasecmp(const char* a, const char* b, size_t length)
{
int c1, c2;
for (; length--; a++, b++)
if (*a != *b)
{
c1 = isalpha(*a) ? tolower(*a) : (int)*a;
c2 = isalpha(*b) ? tolower(*b) : (int)*b;
if ((c1 -= c2))
return c1;
}
else if (!*a && !*b) return 0;
else if (!*a) return -1;
else if (!*b) return +1;
return 0;
}
