dd/
dd.rs

1//! This is not a typical bpaf usage,
2//! but you should be able to replicate command line used by dd
3use bpaf::{any, construct, doc::Style, short, OptionParser, Parser};
4use std::str::FromStr;
5
6#[derive(Debug, Clone)]
7#[allow(dead_code)]
8pub struct Options {
9    magic: bool,
10    in_file: String,
11    out_file: String,
12    block_size: usize,
13}
14
15/// Parses a string that starts with `name`, returns the suffix parsed in a usual way
16fn tag<T>(name: &'static str, meta: &str, help: &'static str) -> impl Parser<T>
17where
18    T: FromStr,
19    <T as std::str::FromStr>::Err: std::fmt::Display,
20{
21    // it is possible to parse OsString here and strip the prefix with
22    // `os_str_bytes` or a similar crate
23    any("", move |s: String| Some(s.strip_prefix(name)?.to_owned()))
24        // this defines custom metavar for the help message
25        .metavar(&[(name, Style::Literal), (meta, Style::Metavar)][..])
26        .help(help)
27        .anywhere()
28        .parse(|s| s.parse())
29}
30
31fn in_file() -> impl Parser<String> {
32    tag::<String>("if=", "FILE", "read from FILE")
33        .fallback(String::from("-"))
34        .display_fallback()
35}
36
37fn out_file() -> impl Parser<String> {
38    tag::<String>("of=", "FILE", "write to FILE")
39        .fallback(String::from("-"))
40        .display_fallback()
41}
42
43fn block_size() -> impl Parser<usize> {
44    // it is possible to parse notation used by dd itself as well,
45    // using usuze only for simplicity
46    tag::<usize>("bs=", "SIZE", "read/write SIZE blocks at once")
47        .fallback(512)
48        .display_fallback()
49}
50
51pub fn options() -> OptionParser<Options> {
52    let magic = short('m')
53        .long("magic")
54        .help("a usual switch still works")
55        .switch();
56    construct!(Options {
57        magic,
58        in_file(),
59        out_file(),
60        block_size(),
61    })
62    .to_options()
63}
64
65fn main() {
66    println!("{:#?}", options().run());
67}
dd/dd.rs

dd/
dd.rs
