Fix code in WASI-tutorial.md
@@ -121,14 +121,14 @@ use std::io::{Read, Write};
fn process(input_fname: &str, output_fname: &str) -> Result<(), String> {
let mut input_file =
- fs::File::open(input_fname).map_err(|err| format!("error opening input: {}", err))?;
+ fs::File::open(input_fname).map_err(|err| format!("error opening input {}: {}", input_fname, err))?;
let mut contents = Vec::new();
input_file
.read_to_end(&mut contents)
.map_err(|err| format!("read error: {}", err))?;
let mut output_file = fs::File::create(output_fname)
- .map_err(|err| format!("error opening output '{}': {}", output_fname, err))?;
+ .map_err(|err| format!("error opening output {}: {}", output_fname, err))?;
output_file
.write_all(&contents)
.map_err(|err| format!("write error: {}", err))
@@ -139,7 +139,7 @@ fn main() {
let program = args[0].clone();
if args.len() < 3 {
- eprintln!("{} <input_file> <output_file>", program);
+ eprintln!("usage: {} <input_file> <output_file>", program);
return;
}
