wc-rs

The good old unix tool rewritten in Rust.

Why write it in Rust?

I wanted to learn Rust and this seemed like a small and simple enough project to get started with. To my surprise this naive implementation turned out to be faster than the original C implementation of wc, take a look at some numbers. This is my first rust project so it might contain some bad code, please raise an issue if you find any room for improvment within the codebase.

Install

• To download and install using cargo run cargo install wc-rs
• To build from source

    git clone https://github.com/palash25/wc-rs.git
    cd wc-rs/
    cargo build --release
  

Usage

Same as the standard wc command that is shipped with every linux distro.

$ wc-rs --help

USAGE:
    wc-rs [FLAGS] [FILE]...

FLAGS:
    -m, --chars      prints the character counts
    -h, --help       Prints help information
    -l, --lines      prints the newline counts
    -V, --version    Prints version information
    -w, --words      print the words counts

ARGS:
    <FILE>...    file path(s) to run wc-rs on

Stats

Testing with 3 files each having 48K lines

Time test

$ \time  wc-rs small-file-*
 48414   81402  556859 small-file-1
 48414   81402  556859 small-file-2
 48414   81402  556859 small-file-3
 145242  244206 1670577 total

 real 0:00.05	 user 0.05	 sys 0.00


$ \time  ./target/release/wc-rs small-file-*
 48414	81402	556859	small-file-1
 48414	81402	556859	small-file-2
 48414	81402	556859	small-file-3
 145242	244206	1670577	total

 real 0:00.02	 user 0.00	 sys 0.01

PV test

$ wc-rs small-file-* | pv
  48414   81402  556859 small-file-1
  48414   81402  556859 small-file-2
  48414   81402  556859 small-file-3
 145242  244206 1670577 total

 159 B 0:00:00 [ 3.1KiB/s] [  <=>                ]

$ ./target/release/wc-rs small-file-* | pv
 48414	81402	556859	small-file-1
 48414	81402	556859	small-file-2
 48414	81402	556859	small-file-3
 145242	244206	1670577	total

 186 B 0:00:00 [9.57KiB/s] [  <=>                ]

Testing with 2 files each having 2 million lines

Time test

$ \time  wc-rs big-file-*
 2091965  3549748 24604624 big-file-1
 2091965  3549748 24604624 big-file-2
 4183930  7099496 49209248 total

 real 0:01.14	 user 1.11	 sys 0.02

$ \time  ./target/release/wc-rs big-file-*
2091965	3549748	24604624	big-file-1
2091965	3549748	24604624	big-file-2
4183930	7099496	49209248	total

 real 0:00.49	 user 0.36	 sys 0.12

PV test

$ wc-rs big-file-* | pv
 2091965  3549748 24604624 big-file-1
 2091965  3549748 24604624 big-file-2
 4183930  7099496 49209248 total

 121 B 0:00:01 [ 101 B/s] [    <=>               ]

$ ./target/release/wc-rs big-file-* | pv
2091965	3549748	24604624	big-file-1
2091965	3549748	24604624	big-file-2
4183930	7099496	49209248	total

 148 B 0:00:00 [ 315 B/s] [  <=>                  ]

Testing with 2 files each having 10 million lines

Time test

$ \time  wc-rs bigger-file-*
 10048406  17328448 124739305 bigger-file-1
 10446226  18017383 129746037 bigger-file-2
 20494632  35345831 254485342 total

 real 0:05.73	 user 5.66	 sys 0.05

$ \time  ./target/release/wc-rs bigger-file-*
 10048406	17328448	124739305	bigger-file-1
 10446226	18017383	129746037	bigger-file-2
 20494632	35345831	254485342	total

 real 0:02.20	 user 1.64	 sys 0.55

PV test

 wc-rs big-file-* | pv
 10048406  17328448 124739305 bigger-file-1
 10446226  18017383 129746037 bigger-file-2
 20494632  35345831 254485342 total

 130 B 0:00:05 [22.5 B/s] [    <=>            ]

 ./target/release/wc-rs bigger-file-* | pv
 10048406  17328448 124739305 bigger-file-1
 10446226  18017383 129746037 bigger-file-2
 20494632  35345831 254485342 total

 157 B 0:00:02 [69.5 B/s] [  <=>              ]

Testing with a denser 10 million line file

This is where things start to slow down a little. This file has double the number of characters than the previous one and almost double the size (~250MB)

Time test

$ \time -p wc-rs big-and-chonky.txt
10048951    31711680    274285495  big-and-chonky.txt

real 4.72   user 4.67   sys 0.04

$ \time -p ./target/release/wc-rs big-and-chonky.txt
10048951	31711680	274285495  big-and-chonky.txt

real 1.89   user 1.36   sys 0.53

PV test

$ wc-rs big-and-chonky.txt | pv
10048951    31711680    274285495   big-and-chonky.txt

46 B 0:00:04 [9.81 B/s] [  <=>                  ]

$ ./target/release/wc-rs big-and-chonky.txt | pv
10048951    31711680    274285495   big-and-chonky.txt

55 B 0:00:01 [29.2 B/s] [  <=>                  ]

TODO

• Read stdin in case no file paths are provided
• Add line lenght flag L
• Add bytes flag c