curl/lib/strcase.c
Daniel Stenberg 3f039dfd6f
strcase: use curl_str(n)equal for case insensitive matches
No point in having two entry points for the same functions.

Also merged the *safe* function treatment into these so that they can
also be used when one or both pointers are NULL.

Closes #9837
2022-11-01 17:01:26 +01:00

205 lines
7.3 KiB
C

/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 1998 - 2022, Daniel Stenberg, <daniel@haxx.se>, et al.
*
* This software is licensed as described in the file COPYING, which
* you should have received as part of this distribution. The terms
* are also available at https://curl.se/docs/copyright.html.
*
* You may opt to use, copy, modify, merge, publish, distribute and/or sell
* copies of the Software, and permit persons to whom the Software is
* furnished to do so, under the terms of the COPYING file.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
* SPDX-License-Identifier: curl
*
***************************************************************************/
#include "curl_setup.h"
#include <curl/curl.h>
#include "strcase.h"
/* Mapping table to go from lowercase to uppercase for plain ASCII.*/
static const unsigned char touppermap[256] = {
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21,
22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59,
60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78,
79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 65,
66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84,
85, 86, 87, 88, 89, 90, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133,
134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149,
150, 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165,
166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181,
182, 183, 184, 185, 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 197,
198, 199, 200, 201, 202, 203, 204, 205, 206, 207, 208, 209, 210, 211, 212, 213,
214, 215, 216, 217, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227, 228, 229,
230, 231, 232, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245,
246, 247, 248, 249, 250, 251, 252, 253, 254, 255
};
/* Mapping table to go from uppercase to lowercase for plain ASCII.*/
static const unsigned char tolowermap[256] = {
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21,
22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41,
42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61,
62, 63, 64, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110,
111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 91, 92, 93, 94, 95,
96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111,
112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127,
128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143,
144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159,
160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175,
176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191,
192, 193, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 204, 205, 206, 207,
208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219, 220, 221, 222, 223,
224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239,
240, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252, 253, 254, 255
};
/* Portable, consistent toupper. Do not use toupper() because its behavior is
altered by the current locale. */
char Curl_raw_toupper(char in)
{
return touppermap[(unsigned char) in];
}
/* Portable, consistent tolower. Do not use tolower() because its behavior is
altered by the current locale. */
char Curl_raw_tolower(char in)
{
return tolowermap[(unsigned char) in];
}
/*
* curl_strequal() is for doing "raw" case insensitive strings. This is meant
* to be locale independent and only compare strings we know are safe for
* this. See https://daniel.haxx.se/blog/2008/10/15/strcasecmp-in-turkish/ for
* further explanations as to why this function is necessary.
*/
static int casecompare(const char *first, const char *second)
{
while(*first && *second) {
if(Curl_raw_toupper(*first) != Curl_raw_toupper(*second))
/* get out of the loop as soon as they don't match */
return 0;
first++;
second++;
}
/* If we're here either the strings are the same or the length is different.
We can just test if the "current" character is non-zero for one and zero
for the other. Note that the characters may not be exactly the same even
if they match, we only want to compare zero-ness. */
return !*first == !*second;
}
/* --- public function --- */
int curl_strequal(const char *first, const char *second)
{
if(first && second)
/* both pointers point to something then compare them */
return casecompare(first, second);
/* if both pointers are NULL then treat them as equal */
return (NULL == first && NULL == second);
}
static int ncasecompare(const char *first, const char *second, size_t max)
{
while(*first && *second && max) {
if(Curl_raw_toupper(*first) != Curl_raw_toupper(*second))
return 0;
max--;
first++;
second++;
}
if(0 == max)
return 1; /* they are equal this far */
return Curl_raw_toupper(*first) == Curl_raw_toupper(*second);
}
/* --- public function --- */
int curl_strnequal(const char *first, const char *second, size_t max)
{
if(first && second)
/* both pointers point to something then compare them */
return ncasecompare(first, second, max);
/* if both pointers are NULL then treat them as equal if max is non-zero */
return (NULL == first && NULL == second && max);
}
/* Copy an upper case version of the string from src to dest. The
* strings may overlap. No more than n characters of the string are copied
* (including any NUL) and the destination string will NOT be
* NUL-terminated if that limit is reached.
*/
void Curl_strntoupper(char *dest, const char *src, size_t n)
{
if(n < 1)
return;
do {
*dest++ = Curl_raw_toupper(*src);
} while(*src++ && --n);
}
/* Copy a lower case version of the string from src to dest. The
* strings may overlap. No more than n characters of the string are copied
* (including any NUL) and the destination string will NOT be
* NUL-terminated if that limit is reached.
*/
void Curl_strntolower(char *dest, const char *src, size_t n)
{
if(n < 1)
return;
do {
*dest++ = Curl_raw_tolower(*src);
} while(*src++ && --n);
}
/* Compare case-sensitive NUL-terminated strings, taking care of possible
* null pointers. Return true if arguments match.
*/
bool Curl_safecmp(char *a, char *b)
{
if(a && b)
return !strcmp(a, b);
return !a && !b;
}
/*
* Curl_timestrcmp() returns 0 if the two strings are identical. The time this
* function spends is a function of the shortest string, not of the contents.
*/
int Curl_timestrcmp(const char *a, const char *b)
{
int match = 0;
int i = 0;
if(a && b) {
while(1) {
match |= a[i]^b[i];
if(!a[i] || !b[i])
break;
i++;
}
}
else
return a || b;
return match;
}