/**
* slibc — Yet another C library
* Copyright © 2015 Mattias Andrée (maandree@member.fsf.org)
*
* 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, either version 3 of the License, or
* (at your option) any later version.
*
* 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, see <http://www.gnu.org/licenses/>.
*/
#include <slibc-human.h>
#include <slibc/internals.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include "escapes.h"
/**
* Escapes a string.
*
* @param str The unescaped string, may be `NULL`.
* @param quote The queue character, must be either ', "
* or a NUL-character (for no surrounding quotes).
* Note, these quotes are not added to output.
* @return Escaped variant of the string, `NULL`.
* You are responsible for deallocating the
* returned pointer.
*
* @throws 0 `str` is `NULL`.
* @throws EINVAL If `quote` is invalid.
* @throws ENOMEM The process cannot allocate more memory.
*
* @since Always.
*/
char* escape(const char* restrict str, int quote)
{
#define OCTAL(s) (*w++ = (char)('0' + ((c >> (s)) & 7)))
#define MODNUL(s) (((unsigned char)((s)[0]) == 0xC0) && ((unsigned char)((s)[1]) == 0x80))
const char* restrict r;
char* restrict w;
char* restrict rc;
size_t extra = 0, len, size;
unsigned char c;
if (str == NULL)
return errno = 0, NULL;
switch (quote)
{
case '\'':
case '\"':
case '\0':
break;
default:
return errno = EINVAL, NULL;
}
for (r = str; (c = (unsigned char)*r); r++)
switch (c)
{
#define X(E, C) case C:
LIST_BIJECTIVE_ESCAPES
#undef X
extra += 1; break;
case 0x7F: extra += 3; break;
default:
if (c == quote) extra += 1;
else if (c < ' ') extra += 3;
break;
}
if (!extra++)
return strdup(str);
len = strlen(str) * sizeof(char);
MEM_OVERFLOW(uaddl, len, extra * sizeof(char), &size);
w = rc = malloc(size);
if (rc == NULL)
return NULL;
for (r = str; (c = (unsigned char)*r); r++)
switch (c)
{
#define X(E, C) case C: *w++ = '\\', *w++ = E; break;
LIST_BIJECTIVE_ESCAPES
#undef X
case 0x7F: w = stpcpy(w, "\\177"); break;
default:
*w++ = '\\';
if (MODNUL(r)) *w++ = '0', r++;
else if (c == quote) *w++ = (char)quote;
else if (c < ' ') OCTAL(6), OCTAL(3), OCTAL(0);
else w[-1] = (char)c;
break;
}
return *w = 0, rc;
}
