utils: add uh_htmlescape() helper

[project/uhttpd.git] / utils.c

diff --git a/utils.c b/utils.c
index 29e03c0b9a3fc83e9b41604a545cf52ec42b35e0..1c61c41fa2ceb9e36845570787787c9c1376e32e 100644 (file)
--- a/utils.c
+++ b/utils.c
@@ -208,6 +208,10 @@ bool uh_path_match(const char *prefix, const char *url)
 {
        int len = strlen(prefix);
 
+       /* A prefix of "/" will - by definition - match any url */
+       if (prefix[0] == '/' && len == 1)
+               return true;
+
        if (strncmp(url, prefix, len) != 0)
                return false;
 
@@ -245,3 +249,45 @@ bool uh_addr_rfc1918(struct uh_addr *addr)
 
        return 0;
 }
+
+
+static bool is_html_special_char(char c)
+{
+       switch (c)
+       {
+       case 0x22:
+       case 0x26:
+       case 0x27:
+       case 0x3C:
+       case 0x3E:
+               return true;
+
+       default:
+               return false;
+       }
+}
+
+char *uh_htmlescape(const char *str)
+{
+       size_t len;
+       char *p, *copy;
+
+       for (p = str, len = 1; *p; p++)
+               if (is_html_special_char(*p))
+                       len += 6; /* &#x??; */
+               else
+                       len++;
+
+       copy = calloc(1, len);
+
+       if (!copy)
+               return NULL;
+
+       for (p = copy; *str; str++)
+               if (is_html_special_char(*str))
+                       p += sprintf(p, "&#x%02x;", (unsigned int)*str);
+               else
+                       *p++ = *str;
+
+       return copy;
+}