Only allow alphanumeric and dots for entrynames

src/main.rs

@@ -324,7 +324,12 @@ fn main() -> Result<(), std::io::Error> {
     let cmdargs: Vec<String> = argv.collect();
     let entryname = cmdargs.get(1);
     if entryname.is_some() {
-        match exec(&entryname.unwrap(), &cmdargs) {
+        let entry = entryname.unwrap();
+        if !entry.chars().all(|c| c.is_alphanumeric() || c == '.') {
+            eprintln!("Entry names can only contain alphanumeric characters and dots");
+            std::process::exit(1);
+        }
+        match exec(entry, &cmdargs) {
             Err(e) => {
                 eprintln!("The following error ocurred:");
                 eprintln!("{}", e);