Refactor: Extract confirm into a new mod

Signed-off-by: Jiahao XU <Jiahao_XU@outlook.com>

src/helpers/confirm.rs

@@ -0,0 +1,21 @@
+use log::info;
+use std::io::{stderr, stdin, Write};
+
+use crate::BinstallError;
+
+pub fn confirm() -> Result<(), BinstallError> {
+    loop {
+        info!("Do you wish to continue? yes/[no]");
+        eprint!("? ");
+        stderr().flush().ok();
+
+        let mut input = String::new();
+        stdin().read_line(&mut input).unwrap();
+
+        match input.as_str().trim() {
+            "yes" | "y" | "YES" | "Y" => break Ok(()),
+            "no" | "n" | "NO" | "N" | "" => break Err(BinstallError::UserAbort),
+            _ => continue,
+        }
+    }
+}