Roller is a simple yet robust text truncation utility written in Rust.

It's really easy to use. Here's an example:

xtitle -s | roller | lemonbar

• xtitle outputs the current window title
• lemonbar generates a status bar on the top of the screen

Roller requires Rust and its package manager, Cargo. Once you have these installed:

git clone https://github.com/kbrgl/roller.git
cd roller
cargo build --release
sudo ln -s ./target/release/roller /usr/bin/roller

sudo pacman -S rust cargo

sudo apt install rust cargo

Roller 1.0.0
Kabir Goel <kabirgoel.kg@gmail.com>
Truncate text by rolling it like a news ticker.

USAGE:
    roller [FLAGS] [OPTIONS]

FLAGS:
    -h, --help       Prints help information
    -m, --mutate     Roll in place instead of on separate lines
    -r, --reverse    Roll in reverse
    -V, --version    Prints version information

OPTIONS:
    -c, --count <NUMBER>           Only roll this many times
    -i, --interval <INTERVAL>      Set a custom interval in milliseconds
    -a, --postfix <POSTFIX>        Append a static postfix to the text
    -b, --prefix <PREFIX>          Prepend a static prefix to the text
    -s, --separator <SEPARATOR>    Place a separator between consecutive rolls
    -t, --truncate <LENGTH>        Only roll if text is longer than LENGTH, effectively truncating it

$ echo 'Rust' | roller -c 5
Rust 
ust R
st Ru
t Rus
 Rust

By default, Roller will refresh if there is any new input on stdin.

$ xtitle -s | roller
~/Code/roller | nvim 
/Code/roller | nvim $
Code/roller | nvim $/
ode/roller | nvim $/C
~ | fish 
 | fish ~
| fish ~ 

• Before the first '~ | fish', I change my currently active window. xtitle outputs the new window title and outputs it. Roller picks up the change.

This option is useful if you want to make sure that the text does not exceed a certain length

$ echo 'Rust' | roller -c 5 -t 5
Rust 
Rust 
Rust 
Rust 
Rust 

Same options, different text:

$ echo 'Rusty.' | roller -c 5 -t 5
Rusty
usty.
sty. 
ty. R
y. Ru

• The -t flag causes text to be 'truncated' at a certain length. This means that if the text exceeds that length then it is scrolled and truncated at given length, otherwise it is neither scrolled nor truncated.

$ echo 'Rust' | roller -c 3 -s ' -- '
Rust -- 
ust -- R
st -- Ru

By default, the separator is a single space. If the default separator was an empty string (''), the output would look like the following:

Rust
ustR
stRu

$ echo 'Rust' | roller -a ' -- ' -b ' .. '
 .. Rust  -- 
 .. ust R -- 
 .. st Ru -- 

Roller is open source software licensed under the terms of the MIT license.