LeOS-Genesis/external/badvpn/misc/concat_strings.h

86 lines
2.7 KiB
C

/**
* @file concat_strings.h
* @author Ambroz Bizjak <ambrop7@gmail.com>
*
* @section LICENSE
*
* 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 the author 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 AUTHOR 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.
*
* @section DESCRIPTION
*
* Function for concatenating strings.
*/
#ifndef BADVPN_MISC_CONCAT_STRINGS_H
#define BADVPN_MISC_CONCAT_STRINGS_H
#include <string.h>
#include <stdlib.h>
#include <stdarg.h>
#include <misc/debug.h>
static char * concat_strings (int num, ...)
{
ASSERT(num >= 0)
// calculate sum of lengths
size_t sum = 0;
va_list ap;
va_start(ap, num);
for (int i = 0; i < num; i++) {
const char *str = va_arg(ap, const char *);
size_t str_len = strlen(str);
if (str_len > SIZE_MAX - 1 - sum) {
va_end(ap);
return NULL;
}
sum += str_len;
}
va_end(ap);
// allocate memory
char *res_str = (char *)malloc(sum + 1);
if (!res_str) {
return NULL;
}
// copy strings
sum = 0;
va_start(ap, num);
for (int i = 0; i < num; i++) {
const char *str = va_arg(ap, const char *);
size_t str_len = strlen(str);
memcpy(res_str + sum, str, str_len);
sum += str_len;
}
va_end(ap);
// terminate
res_str[sum] = '\0';
return res_str;
}
#endif