GopherProxy

	unescape.c - sbase - suckless unix tools
	git clone git://git.suckless.org/sbase
	Log
	Files
	Refs
	README
	LICENSE
	---
	unescape.c (1123B)
	---
	1 /* See LICENSE file for copyright and license details. */
	2 #include <ctype.h>
	3 #include <string.h>
	4
	5 #include "../util.h"
	6
	7 #define is_odigit(c) ('0' <= c && c <= '7')
	8
	9 size_t
	10 unescape(char *s)
	11 {
	12 static const char escapes[256] = {
	13 ['"'] = '"',
	14 ['\''] = '\'',
	15 ['\\'] = '\\',
	16 ['a'] = '\a',
	17 ['b'] = '\b',
	18 ['E'] = 033,
	19 ['e'] = 033,
	20 ['f'] = '\f',
	21 ['n'] = '\n',
	22 ['r'] = '\r',
	23 ['t'] = '\t',
	24 ['v'] = '\v'
	25 };
	26 size_t m, q;
	27 char r, w;
	28
	29 for (r = w = s; *r;) {
	30 if (*r != '\\') {
	31 w++ = r++;
	32 continue;
	33 }
	34 r++;
	35 if (!*r) {
	36 eprintf("null escape sequence\n");
	37 } else if (escapes[(unsigned char)*r]) {
	38 w++ = escapes[(unsigned char)r++];
	39 } else if (is_odigit(*r)) {
	40 for (q = 0, m = 3; m && is_odigit(*r); m--, r++)
	41 q = q * 8 + (*r - '0');
	42 *w++ = MIN(q, 255);
	43 } else if (*r == 'x' && isxdigit(r[1])) {
	44 r++;
	45 for (q = 0, m = 2; m && isxdigit(*r); m--, r++)
	46 if (isdigit(*r))
	47 q = q * 16 + (*r - '0');
	48 else
	49 q = q * 16 + (tolower(*r) - 'a' …
	50 *w++ = q;
	51 } else {
	52 eprintf("invalid escape sequence '\\%c'\n", *r);
	53 }
	54 }
	55 *w = '\0';
	56
	57 return w - s;
	58 }