From 7e8ee5ed9cad6484e9f13f81731b102ced58402e Mon Sep 17 00:00:00 2001 From: Adam Carpenter Date: Tue, 9 Jul 2019 15:14:04 -0400 Subject: Init. --- rust-book/ftoctof/src/main.rs | 43 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) create mode 100755 rust-book/ftoctof/src/main.rs (limited to 'rust-book/ftoctof/src/main.rs') diff --git a/rust-book/ftoctof/src/main.rs b/rust-book/ftoctof/src/main.rs new file mode 100755 index 0000000..6425344 --- /dev/null +++ b/rust-book/ftoctof/src/main.rs @@ -0,0 +1,43 @@ +use std::env; + +fn print_usage() { + eprintln!("error: usage: ftoctof [degrees] [f|c]"); +} + +fn main() { + // grab degrees value + let degrees: f32 = match env::args().nth(1) { + Some(s) => { + let attempt: f32 = s.trim().parse() + .expect("error: could not parse degrees"); + attempt + }, + None => { + print_usage(); + return; + }, + }; + + // grab scale identifier + let scale = match env::args().nth(2) { + Some(s) => s.to_lowercase(), + None => { + print_usage(); + return; + }, + }; + + // compute and print conversion + if scale == "f" { + let result: f32 = (degrees - 32.0) * 5.0 / 9.0; + println!("{} degrees fahrenheight is {} degrees celcius.", degrees, result); + } + else if scale == "c" { + let result: f32 = degrees * 9.0 / 5.0 + 32.0; + println!("{} degrees celcius is {} degrees fahrenheight.", degrees, result); + } + else { + print_usage(); + } + +} -- cgit v1.2.3