alright it does the thing!

fixture/comments.env

@@ -0,0 +1,3 @@
+OH=hey
+# ignore this
+PLEASE=1

fixture/multi.env

@@ -0,0 +1,3 @@
+HELLO=frends
+how=are
+YOU=1

fixture/new-line.env

@@ -0,0 +1,3 @@
+HELLO=1
+
+A=1

fixture/one.env

@@ -0,0 +1 @@
+HEY=1

src/main.rs

@@ -1,3 +1,55 @@
-fn main() {
-    println!("Hello, world!");
+use std::{env, process::ExitCode, fs};
+
+// much more elegant solution than the monstrosity I had gotten to
+// https://stackoverflow.com/a/58113997
+fn bin_name() -> Option<String> {
+    std::env::current_exe()
+        .ok()?
+        .file_name()?
+        .to_str()?
+        .to_owned()
+        .into()
+}
+
+fn main() -> ExitCode {
+    match env::args().skip(1).next() {
+        None => {
+            let bin = match bin_name() {
+                Some(name) => name,
+                None => "read-dotenv".to_owned()
+            };
+
+            // These packages look great but we don't need KBs of
+            // dependencies for three lines of ANSI codes here. :]
+            // https://lib.rs/crates/colored
+            // https://lib.rs/crates/termcolor
+            let red = "\x1b[38;5;203m";
+            let reset = "\x1B[0m";
+            let grey = "\x1b[38;5;247m";
+
+            eprintln!("‼️  {}Provide path to a .env file!{}", red, reset);
+            eprintln!("{}{} ~/example.env{}", grey, bin, reset);
+
+            return ExitCode::FAILURE;
+        },
+        Some(file_path) => {
+            let content = fs::read_to_string(file_path)
+                                .expect("could not read .env file");
+
+            let help = content.split("\n")
+                .filter(|line| !line.is_empty() && !line.starts_with("#"))
+                .map(|line| {
+                    if line.starts_with("export") {
+                        return line.to_owned();
+                    } else {
+                        return format!("export {}", line);
+                    }
+                })
+                .collect::<Vec<_>>()
+                .join("\n");
+
+            println!("{}", help);
+            return ExitCode::SUCCESS;
+        }
+    }
 }