use std::fs::File;
use std::io::{self, Read};
use std::path::PathBuf;
use std::process;
use std::str::FromStr;
use base64::{alphabet, engine, read, write};
use structopt::StructOpt;
#[derive(Debug, StructOpt)]
enum Alphabet {
Standard,
UrlSafe,
}
impl Default for Alphabet {
fn default() -> Self {
Self::Standard
}
}
impl FromStr for Alphabet {
type Err = String;
fn from_str(s: &str) -> Result<Self, String> {
match s {
"standard" => Ok(Self::Standard),
"urlsafe" => Ok(Self::UrlSafe),
_ => Err(format!("alphabet '{}' unrecognized", s)),
}
}
}
/// Base64 encode or decode FILE (or standard input), to standard output.
#[derive(Debug, StructOpt)]
struct Opt {
/// decode data
#[structopt(short = "d", long = "decode")]
decode: bool,
/// The alphabet to choose. Defaults to the standard base64 alphabet.
/// Supported alphabets include "standard" and "urlsafe".
#[structopt(long = "alphabet")]
alphabet: Option<Alphabet>,
/// The file to encode/decode.
#[structopt(parse(from_os_str))]
file: Option<PathBuf>,
}
fn main() {
let opt = Opt::from_args();
let stdin;
let mut input: Box<dyn Read> = match opt.file {
None => {
stdin = io::stdin();
Box::new(stdin.lock())
}
Some(ref f) if f.as_os_str() == "-" => {
stdin = io::stdin();
Box::new(stdin.lock())
}
Some(f) => Box::new(File::open(f).unwrap()),
};
let alphabet = opt.alphabet.unwrap_or_default();
let engine = engine::GeneralPurpose::new(
&match alphabet {
Alphabet::Standard => alphabet::STANDARD,
Alphabet::UrlSafe => alphabet::URL_SAFE,
},
engine::general_purpose::PAD,
);
let stdout = io::stdout();
let mut stdout = stdout.lock();
let r = if opt.decode {
let mut decoder = read::DecoderReader::new(&mut input, &engine);
io::copy(&mut decoder, &mut stdout)
} else {
let mut encoder = write::EncoderWriter::new(&mut stdout, &engine);
io::copy(&mut input, &mut encoder)
};
if let Err(e) = r {
eprintln!(
"Base64 {} failed with {}",
if opt.decode { "decode" } else { "encode" },
e
);
process::exit(1);
}
}
