rush

Warning:: Work in progress.

Succinct & readable processing language for a Unix shell. Written in Rust.

$ echo "Hello " | rh '_ + world'
Hello world

Requirements

Any Unix-like system should do.

Usage

rh [--input <MODE> | --string | --lines | --words | --chars | --bytes | --files]
    [--before <EXPRESSION>]
    [--after <EXPRESSION>]
    <EXPRESSION> [<EXPRESSION> ...]

OPTIONS:
    -i, --input <MODE>
        Defines how the input should be treated when processed by EXPRESSION [values: string, lines, words, chars, bytes, files]
    -s, --string                 Apply the expression once to the whole input as single string
    -l, --lines                  Apply the expression to each line of input as string. This is the default
    -w, --words                  Apply the expression to each word in the input as string.
    -c, --chars                  Apply the expression to each character of input (treated as 1-character string).
    -b, --bytes                  Apply the expression to input bytes. The expression must take byte value as integer and return integer output.
    -f, --files                  Apply the expression to the content of each file (as string) whose path is given as a line of input
    -B, --before <EXPRESSION>
        Optional expression to evaluate before processing the input. The result of this expression is discarded but any side effects (assignments) will persist.
    -A, --after <EXPRESSION>
        Optional expression to evaluate after processing the input. If provided, only the result of this expression will be printed to standard output.

ARGS:
    <EXPRESSION>...
        Expression(s) to apply to input. When multiple expressions are given, the result of one is passed as input to the next one.

Examples

Strings

$ echo 'Alice has a cat' | rh 'before("cat")' '_ + "dog"'
Alice has a dog
$ echo 'Alice has a cat' | rh 'after("Alice")' '"Bob" + _'
Bob has a cat

ROT13

$ echo -n 'flap' | rh -c 'ord' '(_ - ord(a) + 13) % 26' '_ + ord(a)' chr | rh -s 'sub(/\s+/, "")'
sync
$ echo -n 'flap' | rh -s rot13
sync

CSV

$ echo '1,2,3' | rh 'csv & map(int & (*2)) & csv'
2,4,6

$ rh 'csv' '{number: _[0], symbol: _[1], name: _[2], mass: _[3]}'  <./elements.csv
{"mass":"1","name":"Hydrogen","number":"1","symbol":"H"}
{"mass":"4","name":"Helium","number":"2","symbol":"He"}
# etc.

Contributing

You need a Rust toolchain (with Cargo) to build rush itself.

Additionally, the Python-based Invoke task runner is used for automation. It is recommended you install it inside a Python virtualenv. e.g.:

$ virtualenv ~/venv/rush && source ~/venv/rush/bin/activate
$ pip install -r -requirements-dev.txt

Then you can use:

$ inv

to build the binary & the library crate, and run their tests.

License

rush is licensed under the GNU GPL v3 license.

Copyright © 2016, Karol Kuczmarski