/**
* 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 <slib-human.h>
#include <stdlib.h>
#include <string.h>
#include <errno.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.
*/
char* escape(const char* restrict str, char quote)
{
const char* restrict r;
char* restrict w;
char* restrict rc;
size_t extra = 1, 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; *r; r++)
switch (*r)
{
case '\a':
case '\b':
case '\e':
case '\f':
case '\n':
case '\r':
case '\t':
case '\v':
case '\\':
extra += 1;
break;
case 0x7F:
extra += 3;
break;
default:
if (*r == quote)
extra += 1;
else if (*r < ' ')
extra += 3;
break;
}
if (extra == 1)
return strdup(str);
len = strlen(str);
if (__builtin_uaddl_overflow(len, extra, &size))
return errno = ENOMEM, NULL;
w = rc = malloc(size * sizeof(char));
if (w == NULL)
return NULL;
for (r = str; (c = *r); r++)
switch (c)
{
case '\a': *w++ = '\\', *w++ = 'a'; break;
case '\b': *w++ = '\\', *w++ = 'b'; break;
case 033: *w++ = '\\', *w++ = 'e'; break;
case '\f': *w++ = '\\', *w++ = 'f'; break;
case '\n': *w++ = '\\', *w++ = 'n'; break;
case '\r': *w++ = '\\', *w++ = 'r'; break;
case '\t': *w++ = '\\', *w++ = 't'; break;
case '\v': *w++ = '\\', *w++ = 'v'; break;
case '\\': *w++ = '\\', *w++ = '\\'; break;
case 0x7F: *w++ = '\\', *w++ = '1', *w++ = '7', *w++ = '7'; break;
default:
if ((unsigned int)c == 0xC0) && ((unsigned int)(r[1]) == 0x80)
*w++ = '\\', *w++ = '0', r++;
else if (c == quote)
*w++ = '\\', *w++ = quote;
else if (c < ' ')
*w++ = '\\',
*w++ = '0' + (c >> 6),
*w++ = '0' + ((c >> 3) & 7),
*w++ = '0' + (c & 7);
else
*w++ = c;
break;
}
return *w = 0, rc;
}
