fli

fli is a cli tool to list directory content

Why

I have access to my raspberry pi zero via ssh only. As for me it is hard to differentiate types of files etc based on colors, I needed something more readable and clear like picture/icon or emoji as I ended up with etc. And I decided to build fli and since ls is obviosly preinstalled on almost any machine, the second requirement for fli as a complimentary tool, is to be tiny.

Thus fli is a tiny (18KB), easy to read file listing tool.

While working on fli, another aspect of my interest and motivation is to check if with Rust one can build coreutils-like tools, but faster and smaller.

Readability: Nice readability thanks to use of emojis (📄 and 🗂️) instead of text coloring.

Speed: By default directory entries are streamed directly from readdir() to stdout without heap allocation.

Size: Since rust std contributes heavily to binary size, this project is no_std + libc (it contains unsafe code blocks).

Binary size:

• M series mac: 51 KB,
• rpi zero w : 18 KB.

Current display options:

Default fli : short (name and type) sorted by name FLAGS:

• -l : long listing format (name, type, metadata). Default sorting is by name.
• -S : with -l long listing format sorted by size, smallest first.
• -t : with -l long listing format sorted by time, oldest first.
• -r : reverse order while sorting.
• -U : do not sort, list entries in directory order. Alignment is fixed-sized (20 chars for size and n_link) - direct stream, no heap allocation.
• -2 : text output for types :</DIR> <FILE> <LINK> instead of default emojis.
• -0 : color output for types : Dir: Blue, File: Green, Link : Cyan.

Path can be specified as an argument: fli / or fli target/release/fli

New display options may be added soon.

Installation

cargo install fli-tool

note: Running the above command will globally install the fli binary.

Build

Build: cargo build --release

Build with cross for raspberry pi zero w: cross build --release --target arm-unknown-linux-gnueabihf

Copy to rpi : scp /target/arm-unknown-linux-gnueabihf/release/fli <username>@<pi>.local: <target dir>

View

MISC

//arm-linux-gnueabihf
file fli
fli: ELF 32-bit LSB pie executable, ARM, EABI5 version 1 (SYSV), dynamically linked, interpreter /lib/ld-linux-armhf.so.3, for GNU/Linux 4.19.255, stripped

readelf -d fli | grep NEEDED
0x00000001 (NEEDED)                     Shared library: [libc.so.6]
0x00000001 (NEEDED)                     Shared library: [libgcc_s.so.1]

size fli
text    data     bss     dec     hex filename
15308     520       4   15832    3dd8 fli

Benchmarks

it is faster than ls, but it is not the main focus. Still probably need a more sophisticated benchmark later

//20k empty files, sorted by name, macos m-series.
Benchmark 1: /Users/tracyspacy/Documents/GitHub/fli/target/release/fli -l -U
  Time (mean ± σ):      39.8 ms ±   0.6 ms    [User: 14.0 ms, System: 24.6 ms]
  Range (min … max):    38.5 ms …  42.6 ms    60 runs

Benchmark 2: /Users/tracyspacy/Documents/GitHub/fli/target/release/fli -l
  Time (mean ± σ):      46.3 ms ±   0.4 ms    [User: 19.6 ms, System: 25.3 ms]
  Range (min … max):    45.0 ms …  47.4 ms    55 runs

Benchmark 3: /Users/tracyspacy/Documents/GitHub/fli/target/release/fli -l -t
  Time (mean ± σ):      40.8 ms ±   0.6 ms    [User: 14.3 ms, System: 25.0 ms]
  Range (min … max):    39.4 ms …  42.8 ms    62 runs

Benchmark 4: ls -l
  Time (mean ± σ):     145.5 ms ±   1.0 ms    [User: 82.3 ms, System: 61.8 ms]
  Range (min … max):   144.6 ms … 148.3 ms    19 runs

Benchmark 5: ls -l -U
  Time (mean ± σ):     145.4 ms ±   0.3 ms    [User: 82.4 ms, System: 61.7 ms]
  Range (min … max):   144.6 ms … 146.0 ms    19 runs

Benchmark 6: ls -l -t
  Time (mean ± σ):      98.2 ms ±   0.5 ms    [User: 35.7 ms, System: 61.2 ms]
  Range (min … max):    96.8 ms …  99.3 ms    28 runs

Summary
  /Users/tracyspacy/Documents/GitHub/fli/target/release/fli -l -U ran
    1.02 ± 0.02 times faster than /Users/tracyspacy/Documents/GitHub/fli/target/release/fli -l -t
    1.16 ± 0.02 times faster than /Users/tracyspacy/Documents/GitHub/fli/target/release/fli -l
    2.47 ± 0.04 times faster than ls -l -t
    3.65 ± 0.06 times faster than ls -l -U
    3.65 ± 0.06 times faster than ls -l