add client module

src/util.rs

@@ -0,0 +1,28 @@
+use fancy_regex::Regex;
+use rand::Rng;
+
+/// Return the given capture group that matches first in a list of regexes
+pub fn get_cg_from_regexes<'a, I>(mut regexes: I, text: &str, cg: usize) -> Option<String>
+where
+    I: Iterator<Item = &'a Regex>,
+{   
+    regexes
+        .find_map(|pattern| pattern.captures(text).ok().flatten())
+        .map(|c| c.get(cg).unwrap().as_str().to_owned())
+}
+
+/// Generates a random string with given length and byte charset.
+pub fn random_string(charset: &[u8], length: usize) -> String {
+    let mut result = String::with_capacity(length);
+    let mut rng = rand::thread_rng();
+
+    unsafe {
+        for _ in 0..length {
+            result.push(
+                char::from(*charset.get_unchecked(rng.gen_range(0..charset.len())))
+            );
+        }
+    }
+
+    result
+}