+/*
+ * UCW Library -- String Unescaping
+ *
+ * (c) 2006 Pavel Charvat <pchar@ucw.cz>
+ * (c) 2007 Martin Mares <mj@ucw.cz>
+ *
+ * This software may be freely distributed and used according to the terms
+ * of the GNU Lesser General Public License.
+ */
+
+#undef LOCAL_DEBUG
+
+#include "lib/lib.h"
+#include "lib/string.h"
+#include "lib/chartype.h"
+#include <stdlib.h>
+
+/* Expands C99-like escape sequences.
+ * It is safe to use the same buffer for both input and output. */
+char *
+str_unesc(char *d, const char *s)
+{
+ while (*s)
+ {
+ if (*s == '\\')
+ switch (s[1])
+ {
+ case 'a': *d++ = '\a'; s += 2; break;
+ case 'b': *d++ = '\b'; s += 2; break;
+ case 'f': *d++ = '\f'; s += 2; break;
+ case 'n': *d++ = '\n'; s += 2; break;
+ case 'r': *d++ = '\r'; s += 2; break;
+ case 't': *d++ = '\t'; s += 2; break;
+ case 'v': *d++ = '\v'; s += 2; break;
+ case '\?': *d++ = '\?'; s += 2; break;
+ case '\'': *d++ = '\''; s += 2; break;
+ case '\"': *d++ = '\"'; s += 2; break;
+ case '\\': *d++ = '\\'; s += 2; break;
+ case 'x':
+ if (!Cxdigit(s[2]))
+ {
+ s++;
+ DBG("\\x used with no following hex digits");
+ }
+ else
+ {
+ char *p;
+ uns v = strtoul(s + 2, &p, 16);
+ if (v <= 255)
+ *d++ = v;
+ else
+ DBG("hex escape sequence out of range");
+ s = (char *)p;
+ }
+ break;
+ default:
+ if (s[1] >= '0' && s[1] <= '7')
+ {
+ uns v = s[1] - '0';
+ s += 2;
+ for (uns i = 0; i < 2 && *s >= '0' && *s <= '7'; s++, i++)
+ v = (v << 3) + *s - '0';
+ if (v <= 255)
+ *d++ = v;
+ else
+ DBG("octal escape sequence out of range");
+ }
+ *d++ = *s++;
+ break;
+ }
+ else
+ *d++ = *s++;
+ }
+ *d = 0;
+ return d;
+}