diff --git a/Cargo.lock b/Cargo.lock
index 0d991b7..213cfb4 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2,6 +2,231 @@
 # It is not intended for manual editing.
 version = 3
 
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diff --git a/Cargo.toml b/Cargo.toml
index c4c38e6..08a7ffd 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -6,3 +6,5 @@ edition = "2018"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+anyhow = "1.0.44"
+structopt = "0.3.23"
diff --git a/src/main.rs b/src/main.rs
index e7a11a9..e7872e4 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,3 +1,27 @@
-fn main() {
-    println!("Hello, world!");
+use std::fs::File;
+use std::io::Write;
+
+use anyhow::{Context, Result};
+use structopt::StructOpt;
+
+#[derive(StructOpt)]
+struct Cli {
+    #[structopt(parse(from_os_str))]
+    input_file:  std::path::PathBuf,
+    #[structopt(parse(from_os_str))]
+    output_file: std::path::PathBuf,
+}
+
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let args = Cli::from_args();
+
+    let content = std::fs::read_to_string(&args.input_file)
+        .with_context(|| format!("could not read source file {:?}", args.input_file))?;
+
+    let mut out = File::create(args.output_file)?;
+    out.write_all(&content.as_bytes())?;
+
+    out.sync_all()?;
+
+    Ok(())
 }