cosmopolitan/libc/x/unbingbuf.c

52 lines
2.9 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/assert.h"
#include "libc/fmt/bing.internal.h"
#include "libc/log/check.h"
#include "libc/runtime/runtime.h"
#include "libc/stdio/stdio.h"
#include "libc/str/str.h"
/**
* Decodes human-readable CP437 glyphs into binary, e.g.
*
* char binged[5];
* char golden[5] = "\0\1\2\3\4";
* unbingbuf(binged, sizeof(binged), u" ☺☻♥♦", -1);
* CHECK_EQ(0, memcmp(binged, golden, 5));
*
* @param buf is caller owned
* @param size is byte length of buf
* @param glyphs is UCS-2 encoded CP437 representation of binary data
* @param fill if -1 will memset any remaining buffer space
* @note no NUL terminator is added to end of buf
* @see tunbing(), unbingstr(), unbing()
*/
void *unbingbuf(void *buf, size_t size, const char16_t *glyphs, int fill) {
int b;
char *p, *pe;
for (p = buf, pe = p + size; p < pe && *glyphs; ++p, ++glyphs) {
*p = (b = unbing(*glyphs)) & 0xff;
/* DCHECK_NE(-1, b, "%`'hc ∉ IBMCP437\n", *glyphs); */
}
if (fill != -1) memset(p, fill, pe - p);
return buf;
}