cosmopolitan/libc/str/escapedos.c

119 lines
4.3 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/str/str.h"
static textwindows bool shouldescapedos(const char16_t c) {
if (c == u'"') return true;
if (c == u'&') return true;
if (c == u'%') return true;
if (c == u'^') return true;
if (c == u'<') return true;
if (c == u'>') return true;
if (c == u'|') return true;
return false;
}
static textwindows bool shouldquotedos(const char16_t c) {
if (c == u' ') return true;
if (c == u'\t') return true;
if (c == u'\n') return true;
if (c == u'\v') return true;
if (c == u'"') return true;
if (c == u'*') return true;
return shouldescapedos(c);
}
/**
* Escapes command so DOS can run it.
* @see Iain Patterson's NSSM for original code in public domain
*/
textwindows bool escapedos(char16_t *buffer, unsigned buflen,
const char16_t *unquoted, unsigned len) {
unsigned i, j, n;
if (len > buflen - 1) return false;
bool escape = false;
bool quotes = false;
for (i = 0; i < len; i++) {
if (shouldescapedos(unquoted[i])) {
escape = quotes = true;
break;
}
if (shouldquotedos(unquoted[i])) quotes = true;
}
if (!quotes) {
memmove(buffer, unquoted, (len + 1) * sizeof(char16_t));
return true;
}
/* "" */
unsigned quoted_len = 2;
if (escape) quoted_len += 2;
for (i = 0;; i++) {
n = 0;
while (i != len && unquoted[i] == u'\\') {
i++;
n++;
}
if (i == len) {
quoted_len += n * 2;
break;
} else if (unquoted[i] == u'"')
quoted_len += n * 2 + 2;
else
quoted_len += n + 1;
if (shouldescapedos(unquoted[i])) quoted_len += n;
}
if (quoted_len > buflen - 1) return false;
char16_t *s = buffer;
if (escape) *s++ = u'^';
*s++ = u'"';
for (i = 0;; i++) {
n = 0;
while (i != len && unquoted[i] == u'\\') {
i++;
n++;
}
if (i == len) {
for (j = 0; j < n * 2; j++) {
if (escape) *s++ = u'^';
*s++ = u'\\';
}
break;
} else if (unquoted[i] == u'"') {
for (j = 0; j < n * 2 + 1; j++) {
if (escape) *s++ = u'^';
*s++ = u'\\';
}
if (escape && shouldescapedos(unquoted[i])) *s++ = u'^';
*s++ = unquoted[i];
} else {
for (j = 0; j < n; j++) {
if (escape) *s++ = u'^';
*s++ = u'\\';
}
if (escape && shouldescapedos(unquoted[i])) *s++ = u'^';
*s++ = unquoted[i];
}
}
if (escape) *s++ = u'^';
*s++ = u'"';
*s++ = u'\0';
return true;
}