master
Mike Cugini 3 years ago
parent 84c926b8fa
commit 107e692081
  1. 32
      src/main.rs

@ -15,19 +15,17 @@
use std::error::Error; use std::error::Error;
use std::fs::File; use std::fs::File;
use std::io::{self, BufReader};
use std::io::prelude::*; use std::io::prelude::*;
use std::io::{self, BufReader};
use argh::FromArgs; use argh::FromArgs;
#[derive(FromArgs)] #[derive(FromArgs)]
#[argh( #[argh(description = "\
description = "\
chop off bits of file\n\n\ chop off bits of file\n\n\
chop will take produce --count files of --lines lines from the beginning of a\n\ chop will take produce --count files of --lines lines from the beginning of a\n\
file or stdin. Any remaining lines will be written to a final catchall file.")] file or stdin. Any remaining lines will be written to a final catchall file.")]
struct Options { struct Options {
/// number of lines in each chunk /// number of lines in each chunk
#[argh(option, short = 'n')] #[argh(option, short = 'n')]
lines: usize, lines: usize,
@ -51,8 +49,6 @@ struct Options {
/// filename to read from, or "-" for stdin (default "-") /// filename to read from, or "-" for stdin (default "-")
#[argh(positional, default = "String::from(\"-\")")] #[argh(positional, default = "String::from(\"-\")")]
filename: String, filename: String,
} }
struct AlphabeticSuffixGenerator { struct AlphabeticSuffixGenerator {
@ -68,7 +64,10 @@ impl AlphabeticSuffixGenerator {
let mut suffix = vec![b'a'; suffix_length]; let mut suffix = vec![b'a'; suffix_length];
suffix[suffix_length - 1] -= 1; suffix[suffix_length - 1] -= 1;
AlphabeticSuffixGenerator{suffix, remaining: count} AlphabeticSuffixGenerator {
suffix,
remaining: count,
}
} }
} }
@ -77,12 +76,12 @@ impl Iterator for AlphabeticSuffixGenerator {
fn next(&mut self) -> Option<String> { fn next(&mut self) -> Option<String> {
if self.remaining == 0 { if self.remaining == 0 {
return None return None;
} }
for idx in (0..self.suffix.len()).rev() { for idx in (0..self.suffix.len()).rev() {
if self.suffix[idx] < b'z' { if self.suffix[idx] < b'z' {
self.suffix[idx] += 1; self.suffix[idx] += 1;
break break;
} else { } else {
self.suffix[idx] = b'a'; self.suffix[idx] = b'a';
} }
@ -92,17 +91,14 @@ impl Iterator for AlphabeticSuffixGenerator {
} }
} }
fn try_main() -> Result<(), Box<dyn Error>> { fn try_main() -> Result<(), Box<dyn Error>> {
let opts: Options = argh::from_env(); let opts: Options = argh::from_env();
let input: Box<dyn Read> = match opts.filename.as_str() { let input: Box<dyn Read> = match opts.filename.as_str() {
"-" => Box::new(io::stdin()), "-" => Box::new(io::stdin()),
path => { path => match File::open(path) {
match File::open(path) {
Err(why) => panic!("failed to open {}: {}", path, why), Err(why) => panic!("failed to open {}: {}", path, why),
Ok(file) => Box::new(file), Ok(file) => Box::new(file),
}
}, },
}; };
@ -112,7 +108,9 @@ fn try_main() -> Result<(), Box<dyn Error>> {
}; };
let suffix_gen: Box<dyn Iterator<Item = String>> = if opts.numeric { let suffix_gen: Box<dyn Iterator<Item = String>> = if opts.numeric {
Box::new((opts.numeric_start..(opts.numeric_start + opts.count)).map(|num| format!("{}", num))) Box::new(
(opts.numeric_start..(opts.numeric_start + opts.count)).map(|num| format!("{}", num)),
)
} else { } else {
Box::new(AlphabeticSuffixGenerator::new(opts.count)) Box::new(AlphabeticSuffixGenerator::new(opts.count))
}; };
@ -126,8 +124,8 @@ fn try_main() -> Result<(), Box<dyn Error>> {
match reader.read_line(&mut line)? { match reader.read_line(&mut line)? {
0 => { 0 => {
eof = true; eof = true;
break break;
}, }
_ => { _ => {
out_file.write_all(line.as_bytes())?; out_file.write_all(line.as_bytes())?;
line.clear(); line.clear();
@ -141,7 +139,7 @@ fn try_main() -> Result<(), Box<dyn Error>> {
for result in reader.lines() { for result in reader.lines() {
// lines() strips newline characters, so add one // lines() strips newline characters, so add one
out_file.write_all((result? + "\n").as_bytes())?; out_file.write_all((result? + "\n").as_bytes())?;
}; }
} }
Ok(()) Ok(())

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