mirrors/cosmopolitan
1
0
Fork 0
mirror of https://github.com/jart/cosmopolitan.git synced 2025-06-03 11:12:27 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 1

Initial import

Browse source
This commit is contained in:
Justine Tunney 2020-06-15 07:18:57 -07:00
commit c91b3c5006
14915 changed files with 590219 additions and 0 deletions
Download patch file Download diff file Expand all files Collapse all files

64
libc/str/isnotplaintext.c Normal file
View file

@ -0,0 +1,64 @@
/*-*- 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 │
╚─────────────────────────────────────────────────────────────────────────────*/
/**
* Checks if memory address contains non-plain text.
*
* @param data points to memory that's interpreted as char
* @param size is usually strlen(data) and provided by caller
* @return NULL if plain text, or pointer to first non-text datum
* @type char may be 6/7/8/16/32/64-bit signed/unsigned single/multi
* @author Justine Alexandra Roberts Tunney <jtunney@gmail.com>
* @see ASA X3.4, ISO/IEC 646, ITU T.50, ANSI X3.64-1979
* @perf 27gBps on i7-6700 w/ -O3 -mavx2
* @cost 143 bytes of code w/ -Os
*/
void *isnotplaintext(const void *data, size_t size) {
/*
* ASCII, EBCDIC, UNICODE, ISO IR-67, etc. all agree upon the
* encoding of the NUL, SOH, STX, and ETX characters due to a
* longstanding human tradition of using them for the purpose
* of delimiting text from non-text, b/c fixed width integers
* makes their presence in binary formats nearly unavoidable.
*/
#define isnotplain(C) (0 <= (C) && (C) < 4)
char no;
unsigned i;
const char *p, *pe;
if (CHAR_BIT > 6) {
p = (const char *)data;
pe = (const char *)(p + size);
for (; ((intptr_t)p & 31) && p < pe; ++p) {
if (isnotplain(*p)) return p;
}
for (; p + 64 < pe; p += 64) {
no = 0;
for (i = 0; i < 64; ++i) {
no |= isnotplain(p[i]);
}
if (no & 1) break;
}
for (; p < pe; ++p) {
if (isnotplain(*p)) return p;
}
}
return 0;
#undef isnotplain
}