cosmopolitan/libc/str/escapedos.c

118 lines
4.2 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 │
│ │
│ Permission to use, copy, modify, and/or 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. │
╚─────────────────────────────────────────────────────────────────────────────*/
#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;
}