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#[macro_use]
extern crate uucore;
use clap::{App, Arg, ArgMatches};
use std::fs::File;
use std::io::{stdin, stdout, BufRead, BufReader, BufWriter, Read, Write};
use std::iter::repeat;
use std::str::from_utf8;
use unicode_width::UnicodeWidthChar;
static VERSION: &str = env!("CARGO_PKG_VERSION");
static ABOUT: &str = "Convert tabs in each FILE to spaces, writing to standard output.
With no FILE, or when FILE is -, read standard input.";
pub mod options {
pub static TABS: &str = "tabs";
pub static INITIAL: &str = "initial";
pub static NO_UTF8: &str = "no-utf8";
pub static FILES: &str = "FILES";
}
static LONG_HELP: &str = "";
static DEFAULT_TABSTOP: usize = 8;
fn get_usage() -> String {
format!("{0} [OPTION]... [FILE]...", executable!())
}
fn tabstops_parse(s: String) -> Vec<usize> {
let words = s.split(',');
let nums = words
.map(|sn| {
sn.parse::<usize>()
.unwrap_or_else(|_| crash!(1, "{}\n", "tab size contains invalid character(s)"))
})
.collect::<Vec<usize>>();
if nums.iter().any(|&n| n == 0) {
crash!(1, "{}\n", "tab size cannot be 0");
}
if let (false, _) = nums
.iter()
.fold((true, 0), |(acc, last), &n| (acc && last <= n, n))
{
crash!(1, "{}\n", "tab sizes must be ascending");
}
nums
}
struct Options {
files: Vec<String>,
tabstops: Vec<usize>,
tspaces: String,
iflag: bool,
uflag: bool,
}
impl Options {
fn new(matches: &ArgMatches) -> Options {
let tabstops = match matches.value_of(options::TABS) {
Some(s) => tabstops_parse(s.to_string()),
None => vec![DEFAULT_TABSTOP],
};
let iflag = matches.is_present(options::INITIAL);
let uflag = !matches.is_present(options::NO_UTF8);
let nspaces = tabstops
.iter()
.scan(0, |pr, &it| {
let ret = Some(it - *pr);
*pr = it;
ret
})
.max()
.unwrap();
let tspaces = repeat(' ').take(nspaces).collect();
let files: Vec<String> = match matches.values_of(options::FILES) {
Some(s) => s.map(|v| v.to_string()).collect(),
None => vec!["-".to_owned()],
};
Options {
files,
tabstops,
tspaces,
iflag,
uflag,
}
}
}
pub fn uumain(args: impl uucore::Args) -> i32 {
let usage = get_usage();
let matches = App::new(executable!())
.version(VERSION)
.about(ABOUT)
.usage(&usage[..])
.after_help(LONG_HELP)
.arg(
Arg::with_name(options::INITIAL)
.long(options::INITIAL)
.short("i")
.help("do not convert tabs after non blanks"),
)
.arg(
Arg::with_name(options::TABS)
.long(options::TABS)
.short("t")
.value_name("N, LIST")
.takes_value(true)
.help("have tabs N characters apart, not 8 or use comma separated list of explicit tab positions"),
)
.arg(
Arg::with_name(options::NO_UTF8)
.long(options::NO_UTF8)
.short("U")
.help("interpret input file as 8-bit ASCII rather than UTF-8"),
).arg(
Arg::with_name(options::FILES)
.multiple(true)
.hidden(true)
.takes_value(true)
)
.get_matches_from(args);
expand(Options::new(&matches));
0
}
fn open(path: String) -> BufReader<Box<dyn Read + 'static>> {
let file_buf;
if path == "-" {
BufReader::new(Box::new(stdin()) as Box<dyn Read>)
} else {
file_buf = match File::open(&path[..]) {
Ok(a) => a,
Err(e) => crash!(1, "{}: {}\n", &path[..], e),
};
BufReader::new(Box::new(file_buf) as Box<dyn Read>)
}
}
fn next_tabstop(tabstops: &[usize], col: usize) -> usize {
if tabstops.len() == 1 {
tabstops[0] - col % tabstops[0]
} else {
match tabstops.iter().find(|&&t| t > col) {
Some(t) => t - col,
None => 1,
}
}
}
#[derive(PartialEq, Eq, Debug)]
enum CharType {
Backspace,
Tab,
Other,
}
fn expand(options: Options) {
use self::CharType::*;
let mut output = BufWriter::new(stdout());
let ts = options.tabstops.as_ref();
let mut buf = Vec::new();
for file in options.files.into_iter() {
let mut fh = open(file);
while match fh.read_until(b'\n', &mut buf) {
Ok(s) => s > 0,
Err(_) => buf.is_empty(),
} {
let mut col = 0;
let mut byte = 0;
let mut init = true;
while byte < buf.len() {
let (ctype, cwidth, nbytes) = if options.uflag {
let nbytes = char::from(buf[byte]).len_utf8();
if byte + nbytes > buf.len() {
(Other, 1, 1)
} else if let Ok(t) = from_utf8(&buf[byte..byte + nbytes]) {
match t.chars().next() {
Some('\t') => (Tab, 0, nbytes),
Some('\x08') => (Backspace, 0, nbytes),
Some(c) => (Other, UnicodeWidthChar::width(c).unwrap_or(0), nbytes),
None => {
(Other, 1, 1)
}
}
} else {
(Other, 1, 1)
}
} else {
(
match buf[byte] {
0x09 => Tab,
0x08 => Backspace,
_ => Other,
},
1,
1,
)
};
match ctype {
Tab => {
let nts = next_tabstop(ts, col);
col += nts;
if init || !options.iflag {
safe_unwrap!(output.write_all(&options.tspaces[..nts].as_bytes()));
} else {
safe_unwrap!(output.write_all(&buf[byte..byte + nbytes]));
}
}
_ => {
col = if ctype == Other {
col + cwidth
} else if col > 0 {
col - 1
} else {
0
};
if buf[byte] != 0x20 {
init = false;
}
safe_unwrap!(output.write_all(&buf[byte..byte + nbytes]));
}
}
byte += nbytes;
}
safe_unwrap!(output.flush());
buf.truncate(0);
}
}
}