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use std::env;
use crate::{Error, Input, Result};
// NOTE: I assumed I should keep this "DIY". I would most likely use some "de facto" external
// libraries like `clap`, `serde`, ect.
#[derive(Debug, Default)]
pub struct Cli {
pub files: Vec<Input>,
pub opts: Opts,
}
impl Cli {
pub fn parse() -> Result<Self> {
env::args()
.skip(1)
.try_fold(Cli::default(), |mut cli, opt| {
match opt.as_str() {
"-" => cli.files.push(Input::Stdin),
o if o.starts_with("--") => cli.opts.parse_long(o)?,
o if o.starts_with('-') => cli.opts.parse_short(o)?,
s => cli.files.push(s.into()),
};
Ok(cli)
})
.map(|mut cli| {
if cli.files.is_empty() {
cli.files.push(Input::Stdin);
}
cli
})
}
}
#[derive(Debug, Default)]
pub struct Opts {
/// number nonempty output lines, overrides -n
pub number_nonblank: bool,
/// display $ at end of each line
pub show_ends: bool,
/// number all output lines
pub number: bool,
/// suppress repeated empty output lines
pub squeeze_blank: bool,
/// display TAB characters as ^I
pub show_tabs: bool,
/// use ^ and M- notation, except for LFD and TAB
pub show_nonprinting: bool,
/// display help and exit
pub help: bool,
/// output version information and exit
pub version: bool,
}
impl Opts {
fn parse_long(&mut self, s: &str) -> Result<()> {
match s {
"--number-nonblank" => self.number_nonblank = true,
"--show-ends" => self.show_ends = true,
"--number" => self.number = true,
"--squeeze-blank" => self.squeeze_blank = true,
"--show-tabs" => self.show_tabs = true,
"--show-nonprinting" => self.show_nonprinting = true,
"--help" => self.help = true,
"--version" => self.version = true,
s => return Err(Error::Opts(s.to_string())),
};
Ok(())
}
fn parse_short(&mut self, s: &str) -> Result<()> {
for o in s.chars().skip(1) {
match o {
'b' => self.number_nonblank = true,
'E' => self.show_ends = true,
'n' => self.number = true,
's' => self.squeeze_blank = true,
'T' => self.show_tabs = true,
'v' => self.show_nonprinting = true,
s => return Err(Error::Opts(s.to_string())),
};
}
Ok(())
}
}
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