added util::attr_escape

escaping string for inclusion into x(ht)ml attributes

Signed-off-by: Michael Krelin <hacker@klever.net>

1 files changed, 19 insertions, 0 deletions

diff --git a/lib/util.cc b/lib/util.cc
index 54d6535..b7bc437 100644
--- a/lib/util.cc
+++ b/lib/util.cc
@@ -161,6 +161,25 @@ namespace opkele {
             return rv;
         }
 
+        string attr_escape(const string& str) {
+            static const char *unsafechars = "<>&\n\"'";
+            string rv;
+            string::size_type p=0;
+            while(true) {
+                string::size_type us = str.find_first_of(unsafechars,p);
+                if(us==string::npos) {
+                    if(p!=str.length())
+                        rv.append(str,p,str.length()-p);
+                    return rv;
+                }
+                rv.append(str,p,us-p);
+                rv += "&#";
+                rv += long_to_string((long)str[us]);
+                rv += ';';
+                p = us+1;
+            }
+        }
+
         string long_to_string(long l) {
             char rv[32];
             int r=snprintf(rv,sizeof(rv),"%ld",l);