Feat(lib): File I/O,

src/lib.rs

@@ -1,6 +1,8 @@
 use clap::builder::{Arg, Command};
 use clap::{crate_authors, crate_description, crate_name, crate_version, ArgAction, ArgMatches};
 use std::error::Error;
+use std::fs::File;
+use std::io::{self, BufRead, BufReader};
 
 type MyResult<T> = Result<T, Box<dyn Error>>;
 
@@ -34,13 +36,16 @@ pub fn get_args() -> MyResult<Config> {
         .arg(
             Arg::new("number")
                 .short('n')
+                .long("number")
                 .help("Number lines")
                 .num_args(0)
-                .action(ArgAction::SetTrue),
+                .action(ArgAction::SetTrue)
+                .conflicts_with("number_nonblank"),
         )
         .arg(
             Arg::new("number_nonblank")
                 .short('b')
+                .long("number-nonblank")
                 .help("Number nonblank lines")
                 .num_args(0)
                 .action(ArgAction::SetTrue),
@@ -58,8 +63,20 @@ pub fn get_args() -> MyResult<Config> {
     })
 }
 
+fn open(filename: &str) -> MyResult<Box<dyn BufRead>> {
+    match filename {
+        "-" => Ok(Box::new(BufReader::new(io::stdin()))),
+        _ => Ok(Box::new(BufReader::new(File::open(filename)?))),
+    }
+}
+
 pub fn run(config: Config) -> MyResult<()> {
-    dbg!(config);
+    for filepath in config.files {
+        match open(&filepath) {
+            Err(err) => eprintln!("Failed to open {}: {}", filepath, err),
+            Ok(_) => println!("Opened {}", filepath),
+        }
+    }
 
     Ok(())
 }