shitbox/src/cmd/fold/mod.rs
2023-01-13 01:08:32 -05:00

120 lines
3.9 KiB
Rust

use super::Cmd;
use clap::{value_parser, Arg, ArgAction, ArgMatches, Command};
use std::{
fs::File,
io::{self, BufRead, BufReader},
};
use textwrap::{fill, wrap_algorithms::WrapAlgorithm};
#[derive(Debug, Default)]
pub struct Fold;
impl Cmd for Fold {
fn cli(&self) -> Command {
Command::new("fold")
.about("Wrap each input line to fit in specified width")
.author("Nathan Fisher")
.after_long_help("With no FILE, or when FILE is -, read standard input")
.args([
Arg::new("FILE").help("The input file to use").num_args(0..),
Arg::new("BYTES")
.help("Count bytes rather than columns")
.short('b')
.long("bytes")
.action(ArgAction::SetTrue),
Arg::new("WORDS")
.help("Break at spaces")
.short('s')
.long("spaces")
.action(ArgAction::SetTrue),
Arg::new("OPTIMAL")
.help("Optimal fit")
.long_help(
"Uses a look ahad algorithm to avoid unnecessarily short or long lines",
)
.short('o')
.long("optimal")
.action(ArgAction::SetTrue)
.conflicts_with_all(["BYTES", "WORDS"]),
Arg::new("WIDTH")
.help("Use width columns")
.short('w')
.long("width")
.default_value("80")
.num_args(1)
.value_parser(value_parser!(usize)),
])
}
fn run(&self, matches: Option<&ArgMatches>) -> Result<(), Box<dyn std::error::Error>> {
let Some(matches) = matches else {
return Err(Box::new(io::Error::new(io::ErrorKind::Other, "no input")));
};
let files = match matches.get_many::<String>("FILE") {
Some(c) => c.map(String::to_string).collect(),
None => vec!["-".to_string()],
};
for file in files {
if file.as_str() == "-" {
wrap_stdin(matches)?;
} else {
wrap_file(&file, matches)?;
}
}
if matches.get_flag("BYTES") {
println!();
}
Ok(())
}
fn path(&self) -> Option<crate::Path> {
Some(crate::Path::UsrBin)
}
}
fn wrap_line(line: &str, args: &ArgMatches) {
let width = args.get_one("WIDTH").map_or(80, |x| *x);
if args.get_flag("OPTIMAL") {
let line = line.replace('\t', " ");
let opts = textwrap::Options::new(width).wrap_algorithm(WrapAlgorithm::new_optimal_fit());
println!("{}", fill(line.trim_end(), opts));
} else if args.get_flag("WORDS") {
let line = line.replace('\t', " ");
let opts = textwrap::Options::new(width).wrap_algorithm(WrapAlgorithm::FirstFit);
println!("{}", fill(line.trim_end(), opts));
} else if args.get_flag("BYTES") {
for (index, b) in line.as_bytes().iter().enumerate() {
if index % width == 0 {
println!();
}
print!("{}", *b as char);
}
} else {
let line = line
.chars()
.collect::<Vec<char>>()
.chunks(width)
.map(|c| c.iter().collect::<String>())
.collect::<Vec<String>>();
for line in &line {
println!("{}", line);
}
}
}
fn wrap_stdin(args: &ArgMatches) -> Result<(), io::Error> {
for line in io::stdin().lock().lines() {
wrap_line(&line?, args);
}
Ok(())
}
fn wrap_file(file: &str, args: &ArgMatches) -> Result<(), io::Error> {
let fd = File::open(file)?;
let buf = BufReader::new(fd);
for line in buf.lines() {
wrap_line(&line?, args);
}
Ok(())
}