1 files changed, 18 insertions, 87 deletions

diff --git a/src/cli.rs b/src/cli.rs
index bab0b84..12f1cfc 100644
--- a/src/cli.rs
+++ b/src/cli.rs
@@ -1,36 +1,14 @@
-use std::{
-    env,
-    io::{BufRead, BufReader, Write},
-};
+use std::env;
 
 use crate::{Error, Input, Result};
 
-const HELP: &str = r#"Usage: cat [OPTION]... [FILE]...
-Concatenate FILE(s) to standard output.
-
-With no FILE, or when FILE is -, read standard input.
-
-  -A, --show-all           equivalent to -vET
-  -b, --number-nonblank    number nonempty output lines, overrides -n
-  -e                       equivalent to -vE
-  -E, --show-ends          display $ at end of each line
-  -n, --number             number all output lines
-  -s, --squeeze-blank      suppress repeated empty output lines
-  -t                       equivalent to -vT
-  -T, --show-tabs          display TAB characters as ^I
-  -u                       (ignored)
-  -v, --show-nonprinting   use ^ and M- notation, except for LFD and TAB
-      --help        display this help and exit
-      --version     output version information and exit
-
-Examples:
-  cat f - g  Output f's contents, then standard input, then g's contents.
-  cat        Copy standard input to standard output."#;
+// NOTE: I assumed I should keep this "DIY". I would  most likely use some "de facto" external
+// libraries like `clap`, `serde`, ect.
 
 #[derive(Debug, Default)]
 pub struct Cli {
-    files: Vec<Input>,
-    opts: Opts,
+    pub files: Vec<Input>,
+    pub opts: Opts,
 }
 
 impl Cli {
@@ -46,87 +24,40 @@ impl Cli {
                 };
                 Ok(cli)
             })
-    }
-
-    pub fn run(mut self) -> Result<()> {
-        if self.opts.help {
-            println!("{}", HELP);
-            std::process::exit(0);
-        }
-        if self.opts.version {
-            println!("cat (ported to Rust) {}", env!("CARGO_PKG_VERSION"));
-            std::process::exit(0);
-        }
-
-        if self.files.is_empty() {
-            self.files.push(Input::Stdin);
-        }
-
-        let stdout = std::io::stdout();
-        let mut writer = stdout.lock();
-
-        for file in self.files.into_iter() {
-            let reader = BufReader::new(file.reader()?);
-
-            let mut nonblank_line_nr = 0;
-
-            for (index, res) in reader.lines().enumerate() {
-                let mut line = res?;
-
-                if line.is_empty() && self.opts.squeeze_blank {
-                    continue;
-                }
-
-                if self.opts.show_ends {
-                    line.push('$');
-                }
-
-                if self.opts.show_tabs {
-                    line = line.replace('\t', "^I");
-                }
-
-                if self.opts.number_nonblank {
-                    if !line.is_empty() {
-                        nonblank_line_nr += 1;
-                        write!(writer, "{:>6}  ", nonblank_line_nr)?;
-                    }
-                } else if self.opts.number {
-                    write!(writer, "{:>6}  ", index + 1)?;
+            .map(|mut cli| {
+                if cli.files.is_empty() {
+                    cli.files.push(Input::Stdin);
                 }
-
-                writeln!(writer, "{}", line)?;
-            }
-        }
-
-        Ok(())
+                cli
+            })
     }
 }
 
 #[derive(Debug, Default)]
 pub struct Opts {
     /// number nonempty output lines, overrides -n
-    number_nonblank: bool,
+    pub number_nonblank: bool,
 
     /// display $ at end of each line
-    show_ends: bool,
+    pub show_ends: bool,
 
     /// number all output lines
-    number: bool,
+    pub number: bool,
 
     /// suppress repeated empty output lines
-    squeeze_blank: bool,
+    pub squeeze_blank: bool,
 
     /// display TAB characters as ^I
-    show_tabs: bool,
+    pub show_tabs: bool,
 
     /// use ^ and M- notation, except for LFD and TAB
-    show_nonprinting: bool,
+    pub show_nonprinting: bool,
 
     /// display help and exit
-    help: bool,
+    pub help: bool,
 
     /// output version information and exit
-    version: bool,
+    pub version: bool,
 }
 
 impl Opts {