aded util::url_decode()

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

1 files changed, 28 insertions, 0 deletions

diff --git a/lib/util.cc b/lib/util.cc
index a6e08e2..3e7f3aa 100644
--- a/lib/util.cc
+++ b/lib/util.cc
@@ -171,48 +171,76 @@ namespace opkele {
 	    public:
 		string& rv;
 
 		__url_encoder(string& r) : rv(r) { }
 
 		result_type operator()(argument_type c) {
 		    if(isrfc3986unreserved(c))
 			rv += c;
 		    else{
 			char tmp[4];
 			snprintf(tmp,sizeof(tmp),"%%%02X",
 				(c&0xff));
 			rv += tmp;
 		    }
 		}
 	};
 
 	string url_encode(const string& str) {
 	    string rv;
 	    for_each(str.begin(),str.end(),
 		    __url_encoder(rv));
 	    return rv;
 	}
 
+	string url_decode(const string& str) {
+	    string rv;
+	    back_insert_iterator<string> ii(rv);
+	    for(string::const_iterator i=str.begin(),ie=str.end();
+		    i!=ie;++i) {
+		switch(*i) {
+		    case '+':
+			*(ii++) = ' '; break;
+		    case '%':
+			++i;
+			static char tmp[3] = {0,0,0};
+			if(i==ie)
+			    throw failed_conversion(OPKELE_CP_ "trailing percent in the url-encoded string");
+			tmp[0] == *(i++);
+			if(i==ie)
+			    throw failed_conversion(OPKELE_CP_ "not enough hexadecimals after the percent sign in url-encoded string");
+			tmp[1] == *i;
+			if(!(isxdigit(tmp[0]) && isxdigit(tmp[1])))
+			    throw failed_conversion(OPKELE_CP_ "non-hex follows percent in url-encoded string");
+			*(ii++) = strtol(tmp,0,16);
+			break;
+		    default:
+			*(ii++) = *i; break;
+		}
+	    }
+	    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);
 	    if(r<0 || r>=(int)sizeof(rv))
 		throw failed_conversion(OPKELE_CP_ "failed to snprintf()");