cosmopolitan/libc/str/strcspn.c

40 lines
2.3 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney │
│ │
│ 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; version 2 of the License. │
│ │
│ 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, write to the Free Software │
│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA │
│ 02110-1301 USA │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/nexgen32e/hascharacter.internal.h"
#include "libc/str/str.h"
/**
* Returns prefix length, consisting of chars not in reject.
* a.k.a. Return index of first byte that's in charset.
*
* @param reject is nul-terminated character set
* @see strspn(), strtok_r()
* @asyncsignalsafe
*/
size_t strcspn(const char *s, const char *reject) {
size_t i;
for (i = 0; s[i]; ++i) {
if (HasCharacter(s[i], reject)) {
break;
}
}
return i;
}