reorganizing extension commands

src/ext.rs

@@ -0,0 +1,5 @@
+mod tail;
+mod command;
+
+pub use tail::Tail;
+pub use command::Command;

src/ext/command.rs

@@ -0,0 +1,7 @@
+pub trait Command {
+    fn name() -> String;
+
+    fn create() -> Self;
+
+    fn exec(&mut self, args: Vec<&str>) -> anyhow::Result<bool>;
+}

src/ext/tail.rs

@@ -0,0 +1,58 @@
+use crate::{
+    ext::Command,
+    output,
+};
+
+use std::{
+    fs::File,
+    io::{Seek, SeekFrom, Read, Write},
+};
+
+use anyhow::Result;
+
+pub struct Tail { }
+
+impl Command for Tail {
+    fn name() -> String {
+        String::from("tail")
+    }
+
+    fn create() -> Self {
+        Self{ }
+    }
+
+    fn exec(&mut self, args: Vec<&str>) -> Result<bool> {
+        let mut stdout = output::Writer::stdout()?;
+        if args.len() > 0 {
+            let fname = args[0];
+            match File::options().read(true).open(fname) {
+                Ok(mut f) => {
+                    _ = f.seek(SeekFrom::End(0));
+                    let mut one_byte: [u8; 1] = [0; 1];
+                    let mut buf: Vec<u8> = vec![];
+                    loop {
+                        match f.read(&mut one_byte) {
+                            Ok(n) => {
+                                if n == 1 {
+                                    buf.push(one_byte[0]);
+                                    if let Ok(s) = std::str::from_utf8(&buf) {
+                                        stdout.write(s.as_bytes())?;
+                                        buf.clear();
+                                    }
+                                }
+                            }
+                            Err(_) => {}
+                        }
+                    }
+                }
+                Err(e) => {
+                    println!("failed to open file: {}", e);
+                    return Err(e.into());
+                }
+            }
+        } else {
+            println!("need a file name");
+            return Ok(false);
+        }
+    }
+}

src/main.rs

@@ -1,20 +1,21 @@
 mod error;
+mod ext;
 mod input;
 mod key;
 mod line;
 mod log;
 mod output;
-mod shell;
 mod prompt;
+mod shell;
 
+use crate::log::*;
 use prompt::Prompt;
+use shell::Shell;
+
 use std::io::Write;
 
 use anyhow::Result;
 
-use crate::log::*;
-use shell::Shell;
-
 fn main() -> Result<()> {
     let mut shell = Shell::new()?;
     let log_path = shell.expand_path("~/wash.log");
@@ -120,7 +121,9 @@ fn main() -> Result<()> {
                 if event.ctrl && event.code == key::J {
                     debug!("⎈ j: dot");
                     // red bullet
-                    shell.output.write(String::from("\x1b[31m\u{2022}\x1b[0m").as_bytes())?;
+                    shell
+                        .output
+                        .write(String::from("\x1b[31m\u{2022}\x1b[0m").as_bytes())?;
                     continue;
                 }
 

src/output.rs

@@ -94,26 +94,28 @@ fn log_output_mode(mode: Console::CONSOLE_MODE) {
     }
 }
 
-fn stdout_handle() -> Result<HANDLE> {
-    unsafe {
-        let handle = Console::GetStdHandle(Console::STD_OUTPUT_HANDLE)
-            .context("unable to get stdin handle")?;
-        Ok(handle)
-    }
-}
-
 pub struct Writer {
     output: HANDLE,
 }
 
 impl Writer {
-    pub fn new() -> Result<Self> {
+    pub fn stdout() -> Result<Self> {
-        let mut v = Self {
+        unsafe {
-            output: stdout_handle()?,
+            let handle = Console::GetStdHandle(Console::STD_OUTPUT_HANDLE)
-        };
+                .context("unable to get stdin handle")?;
-        v.reset()?;
+            let mut stdout = Self{output: handle};
-        Ok(v)
+            stdout.reset()?;
+            Ok(stdout)
         }
+    }
+
+    // pub fn new() -> Result<Self> {
+    //     let mut v = Self {
+    //         output: stdout_handle()?,
+    //     };
+    //     v.reset()?;
+    //     Ok(v)
+    // }
 
     pub fn close(&mut self) -> Result<()> {
         unsafe {

src/shell.rs

@@ -1,4 +1,4 @@
-use crate::{input, line::Line, log::*, output};
+use crate::{input, line::Line, log::*, output, ext::{Command, Tail}};
 
 use std::{
     fs::File,
@@ -19,7 +19,7 @@ impl Shell {
     pub fn new() -> Result<Self> {
         Ok(Self {
             input: input::Reader::new()?,
-            output: output::Writer::new()?,
+            output: output::Writer::stdout()?,
             line: Line::new(),
         })
     }
@@ -145,39 +145,7 @@ impl Shell {
                     return Ok(false);
                 }
             }
-            "tail" => {
+            "tail" => Tail::create().exec(args),
-                if args.len() > 0 {
-                    let fname = args[0];
-                    match File::options().read(true).open(fname) {
-                        Ok(mut f) => {
-                            _ = f.seek(SeekFrom::End(0));
-                            let mut one_byte: [u8; 1] = [0; 1];
-                            let mut buf: Vec<u8> = vec![];
-                            loop {
-                                match f.read(&mut one_byte) {
-                                    Ok(n) => {
-                                        if n == 1 {
-                                            buf.push(one_byte[0]);
-                                            if let Ok(s) = std::str::from_utf8(&buf) {
-                                                self.output.write(s.as_bytes())?;
-                                                buf.clear();
-                                            }
-                                        }
-                                    }
-                                    Err(_) => {}
-                                }
-                            }
-                        }
-                        Err(e) => {
-                            println!("failed to open file: {}", e);
-                            return Err(e.into());
-                        }
-                    }
-                } else {
-                    println!("need a file name");
-                    return Ok(false);
-                }
-            }
             "echo" => {
                 println!("{}", args.join(" "));
                 return Ok(true);