little refactor+cleanup

src/main.rs

@@ -1,10 +1,10 @@
 extern crate clap;
-use clap::{App, Arg};
+use clap::{App, Arg, ArgMatches};
 use isatty::stdout_isatty;
 use std::env;
 use std::fs::File;
 use std::io::{prelude::*, BufReader};
-use std::path::Path;
+use std::path::{Path, PathBuf};
 
 fn current_args() -> String {
     let mut out = String::from("osenv");
@@ -14,6 +14,22 @@ fn current_args() -> String {
     out
 }
 
+fn get_file(cmd: &ArgMatches) -> Option<PathBuf> {
+    let dir = cmd.value_of("directory")?;
+    let file = cmd.value_of("file")?;
+    let env = cmd.value_of("environment");
+
+    // If -env was specified, add it as a suffix
+    let filename = if env.is_some() {
+        format!("{}.{}", file, env.unwrap())
+    } else {
+        String::from(file)
+    };
+
+    // Join directory and file
+    Some(Path::new(dir).join(filename))
+}
+
 fn main() -> std::io::Result<()> {
     #[cfg(target_os = "macos")]
     static OS_DEFAULT_SHELL: &str = "sh";
@@ -63,21 +79,9 @@ fn main() -> std::io::Result<()> {
         )
         .get_matches();
 
-    let dir = cmd.value_of("directory").unwrap();
-    let file = cmd.value_of("file").unwrap();
-    let env = cmd.value_of("environment");
+    let path = get_file(&cmd).unwrap();
     let shell = cmd.value_of("shell").unwrap();
 
-    // If -env was specified, add it as a suffix
-    let filename = if env.is_some() {
-        format!("{}.{}", file, env.unwrap())
-    } else {
-        String::from(file)
-    };
-
-    // Join directory and file
-    let path = Path::new(dir).join(filename);
-
     if !path.exists() {
         println!("{}: file not found", path.display());
         std::process::exit(1);
@@ -88,9 +92,16 @@ fn main() -> std::io::Result<()> {
 
     // Print help messages if printing to terminal
     if stdout_isatty() {
+        println!("# It looks like you are not running osenv properly");
         match shell {
-            "ps1" => println!("#\n# It looks like you are not running osenv properly\n# The proper command on Powershell is:\n#    {} | iex\n# Hope this helps!\n#", current_args()),
-            "sh" => println!("#\n# It looks like you are not running osenv properly\n# The proper command on unix shells is:\n#    eval $({})\n# Hope this helps!\n#", current_args()),
+            "ps1" => println!(
+                "# The proper command on Powershell is:\n#    {} | iex",
+                current_args()
+            ),
+            "sh" => println!(
+                "# The proper command on unix shells is:\n#    eval $({})",
+                current_args()
+            ),
             _ => (),
         }
     }