html.c: add html_url_arg

This function can be used to properly escape querystring parameter values.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>

1 files changed, 16 insertions, 0 deletions

diff --git a/html.c b/html.c
index 36e9a2f..167127f 100644
--- a/html.c
+++ b/html.c
@@ -123,16 +123,32 @@ void html_attr(char *txt)
                         txt = t+1;
                 }
                 t++;
         }
         if (t!=txt)
                 html(txt);
 }
 
+void html_url_arg(char *txt)
+{
+        char *t = txt;
+        while(t && *t){
+                int c = *t;
+                if (c=='"' || c=='#' || c=='%' || c=='&' || c=='\'' || c=='+' || c=='?') {
+                        write(htmlfd, txt, t - txt);
+                        write(htmlfd, fmt("%%%2x", c), 3);
+                        txt = t+1;
+                }
+                t++;
+        }
+        if (t!=txt)
+                html(txt);
+}
+
 void html_hidden(char *name, char *value)
 {
         html("<input type='hidden' name='");
         html_attr(name);
         html("' value='");
         html_attr(value);
         html("'/>");
 }