sortix-mirror/libc/string/stresep.c

60 lines
1.6 KiB
C

/*
* Copyright (c) 2014 Jonas 'Sortie' Termansen.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
* string/stresep.c
* Extract a token from a string while handling escape characters.
*/
#include <stdbool.h>
#include <string.h>
char* stresep(char** string_ptr, const char* delim, int escape)
{
char* token = *string_ptr;
if ( !token )
return NULL;
size_t consumed_length = 0;
size_t token_length = 0;
bool escaped = false;
while ( true )
{
char c = token[consumed_length++];
bool true_nul = c == '\0';
if ( !escaped && escape && (unsigned char) c == (unsigned char) escape )
{
escaped = true;
continue;
}
if ( !escaped && c != '\0' )
{
for ( size_t i = 0; delim[i]; i++ )
{
if ( c != delim[i] )
{
c = '\0';
break;
}
}
}
token[token_length++] = c;
escaped = false;
if ( c == '\0' )
{
*string_ptr = true_nul ? (char*) NULL : token + consumed_length;
return token;
}
}
}