1 files changed, 48 insertions, 0 deletions
diff --git a/api/urlcode.c b/api/urlcode.c
new file mode 100644
index 0000000..ecf34e1
--- /dev/null
+++ b/api/urlcode.c
@@ -0,0 +1,48 @@
+/* Converts a hex character to its integer value */
+char from_hex(char ch) {
+  return isdigit(ch) ? ch - '0' : tolower(ch) - 'a' + 10;
+}
+
+/* Converts an integer value to its hex character*/
+char to_hex(char code) {
+  static char hex[] = "0123456789abcdef";
+  return hex[code & 15];
+}
+
+/* Returns a url-encoded version of str */
+/* IMPORTANT: be sure to free() the returned string after use */
+char *url_encode(char *str) {
+  char *pstr = str, *buf = malloc(strlen(str) * 3 + 1), *pbuf = buf;
+  while (*pstr) {
+    if (isalnum(*pstr) || *pstr == '-' || *pstr == '_' || *pstr == '.' || *pstr == '~') 
+      *pbuf++ = *pstr;
+    else if (*pstr == ' ') 
+      *pbuf++ = '+';
+    else 
+      *pbuf++ = '%', *pbuf++ = to_hex(*pstr >> 4), *pbuf++ = to_hex(*pstr & 15);
+    pstr++;
+  }
+  *pbuf = '\0';
+  return buf;
+}
+
+/* Returns a url-decoded version of str */
+/* IMPORTANT: be sure to free() the returned string after use */
+char *url_decode(char *str) {
+  char *pstr = str, *buf = malloc(strlen(str) + 1), *pbuf = buf;
+  while (*pstr) {
+    if (*pstr == '%') {
+      if (pstr[1] && pstr[2]) {
+        *pbuf++ = from_hex(pstr[1]) << 4 | from_hex(pstr[2]);
+        pstr += 2;
+      }
+    } else if (*pstr == '+') { 
+      *pbuf++ = ' ';
+    } else {
+      *pbuf++ = *pstr;
+    }
+    pstr++;
+  }
+  *pbuf = '\0';
+  return buf;
+}