docs, errors and basic api

src/utils.rs

@@ -0,0 +1,18 @@
+use regex::Regex;
+
+use crate::SbotCliError;
+
+/// Return matches for a given Regex pattern and text.
+///
+/// # Arguments
+///
+/// * `pattern` - A string slice representing a regular expression
+/// * `input` - A string slice representing the input to be matched on
+///
+pub fn regex_finder(pattern: &str, input: &str) -> Result<Option<String>, SbotCliError> {
+    let re = Regex::new(pattern)?;
+    let caps = re.captures(input);
+    let result = caps.map(|caps| caps[1].to_string());
+
+    Ok(result)
+}