Signed-off-by: Mattias Andrée <maand...@kth.se>
---
libutil/unescape.c | 98 ++++++++++++++++++++++--------------------------------
1 file changed, 39 insertions(+), 59 deletions(-)
diff --git a/libutil/unescape.c b/libutil/unescape.c
index d1503e6..c0155ea 100644
--- a/libutil/unescape.c
+++ b/libutil/unescape.c
@@ -1,74 +1,54 @@
/* See LICENSE file for copyright and license details. */
+#include <ctype.h>
#include <string.h>
#include "../util.h"
+#define isoctal(c) ('0' <= c && c <= '7')
+
size_t
unescape(char *s)
{
- size_t len, i, off, m, factor, q;
-
- len = strlen(s);
+ static const char escapes[256] = {
+ ['"'] = '"',
+ ['\''] = '\'',
+ ['\\'] = '\\',
+ ['a'] = '\a',
+ ['b'] = '\b',
+ ['E'] = 033,
+ ['e'] = 033,
+ ['f'] = '\f',
+ ['n'] = '\n',
+ ['r'] = '\r',
+ ['t'] = '\t',
+ ['v'] = '\v'
+ };
+ size_t m, q;
+ char *r, *w;
- for (i = 0; i < len; i++) {
- if (s[i] != '\\')
+ for (r = w = s; *r;) {
+ if (*r != '\\') {
+ *w++ = *r++;
continue;
- off = 0;
-
- switch (s[i + 1]) {
- case '\\': s[i] = '\\'; off++; break;
- case '\'': s[i] = '\'', off++; break;
- case '"': s[i] = '"', off++; break;
- case 'a': s[i] = '\a'; off++; break;
- case 'b': s[i] = '\b'; off++; break;
- case 'e': s[i] = 033; off++; break;
- case 'f': s[i] = '\f'; off++; break;
- case 'n': s[i] = '\n'; off++; break;
- case 'r': s[i] = '\r'; off++; break;
- case 't': s[i] = '\t'; off++; break;
- case 'v': s[i] = '\v'; off++; break;
- case 'x':
- /* "\xH[H]" hexadecimal escape */
- for (m = i + 2; m < i + 1 + 3 && m < len; m++)
- if ((s[m] < '0' && s[m] > '9') &&
- (s[m] < 'A' && s[m] > 'F') &&
- (s[m] < 'a' && s[m] > 'f'))
- break;
- if (m == i + 2)
- eprintf("invalid escape sequence '\\%c'\n", s[i
+ 1]);
- off += m - i - 1;
- for (--m, q = 0, factor = 1; m > i + 1; m--) {
- if (s[m] >= '0' && s[m] <= '9')
- q += (s[m] - '0') * factor;
- else if (s[m] >= 'A' && s[m] <= 'F')
- q += ((s[m] - 'A') + 10) * factor;
- else if (s[m] >= 'a' && s[m] <= 'f')
- q += ((s[m] - 'a') + 10) * factor;
- factor *= 16;
- }
- s[i] = q;
- break;
- case '\0':
+ }
+ r++;
+ if (!*r) {
eprintf("null escape sequence\n");
- default:
- /* "\O[OOO]" octal escape */
- for (m = i + 1; m < i + 1 + 4 && m < len; m++)
- if (s[m] < '0' || s[m] > '7')
- break;
- if (m == i + 1)
- eprintf("invalid escape sequence '\\%c'\n", s[i
+ 1]);
- off += m - i - 1;
- for (--m, q = 0, factor = 1; m > i; m--) {
- q += (s[m] - '0') * factor;
- factor *= 8;
- }
- s[i] = (q > 255) ? 255 : q;
+ } else if (escapes[*r & 255]) {
+ *w++ = escapes[*r++ & 255];
+ } else if (isoctal(*r)) {
+ for (q = 0, m = 4; m && isoctal(*r); m--, r++)
+ q = q * 8 + (*r & 7);
+ *w++ = q > 255 ? 255 : q;
+ } else if (*r == 'x' && isxdigit(r[1])) {
+ r++;
+ for (q = 0, m = 2; m && isxdigit(*r); m--, r++)
+ q = q * 16 + (*r & 15) + 9 * isalpha(*r);
+ *w++ = q;
+ } else {
+ eprintf("invalid escape sequence '\\%c'\n", *r);
}
-
- for (m = i + 1; m <= len - off; m++)
- s[m] = s[m + off];
- len -= off;
}
- return len;
+ return w - s;
}
--
2.11.0
