coderofsalvation / Powscript

write shellscript in a powful way!

Usage

$ wget "https://raw.githubusercontent.com/coderofsalvation/powscript/master/powscript" -O /usr/local/bin/powscript && chmod 755 /usr/local/bin/powscript
$ powscript myscript.pow                          # run directly
$ powscript -c myscript.pow > myscript            # output bashscript
$ powscript -c --to sh myscript.pow > myscript.sh # output sh-script (experimental)

• unnoficial AUR package

Wiki

• Syntax reference
• Modules / Developer Info / Contribution / Similar Projects / Why

Example

#!/usr/bin/env powscript
require_cmd 'echo'
require_env 'TERM'

error(msg exitcode)
  echo "error: $msg"
  if set? $exitcode
    exit $exitcode

run(@args -- foo)
  if empty? foo
    error "please pass --foo <string>" 1
  echo $args[@] "$foo universe!!"
  echo "HOME=$HOME"

run [email protected]

Output:

$ powscript -c foo.pow -o foo.bash
$ ./foo.bash hello --foo powful
hello powful universe!
HOME=/home/yourusername

Check a json example here and here for more examples

Features

• indentbased, memorizable, coffeescript-inspired syntax
• removes semantic noise like { ! [[ @ ]] || ~=
• safetynets: automatic quoting, halt on error or missing dependencies (require_cmd,require_env)
• comfort: json, easy arrays, easy async, functional programming, named variables instead of positionals
• Modules / bundling
• remote/local packages & dependencies
• written/generated for bash >= 4.x, 'zero'-dependency solution for embedded devices e.g.
• hasslefree: easy installation without gcc compilation/3rd party software

Examples

• m3uchecker (19 lines powscript vs 57 lines bash)
• pm.sh
• Collection of codesnippets

Interactive mode (experimental)

Put this line in your .inputrc:

"\C-p" "powscript --interactive\n"

Then hitting ctrl-p in your console will enter powscript mode:

hit ctrl-c to exit powscript, type 'edit' to launch editor, and 'help' for help
> each(line)
>   echo line=$line
> run()
>   tail -2 ~/.kanban.csv | mappipe each
> run
line=1,foo,bar,flop
line=2,foo2,bar2,flop2
>

POSIX /bin/sh compatibility

Powscript can produce 'kindof' POSIX /bin/sh-compatible output by removing bashisms, by introducing the --sh flag:

$ powscript --c foo.pow -o foo.bash
$ powscript --to sh --c foo.pow -o foo.sh

This however, is experimental, as well as the standalone bash2sh converter:

$ cat foo.bash | powscript --to sh  > foo.sh

NOTE: remove bashisms manually using docs/tools like bashism guide or checkbashisms The general rule for POSIX sh-output is: don't write bashfeatures in powscript

Debug your powscript syntax

See FAQ

OSX users

OSX might protest since it isn't quite GNU focused. Please run these commands after installing:

$ brew install bash
$ brew install coreutils gnu-sed grep gawk --default-names
$ echo 'export PATH=/usr/local/opt/coreutils/libexec/gnubin:$PATH' >> ~/.bashrc
$ sed -i 's|#!/bin/bash|#!/usr/local/bin/bash|g' powscript

Live expansion inside editor

HINT: use live expansion inside vim. Put the lines below in .vimrc and hit 'p>' in normal/visual mode to expand powscript to bash

vmap p> :!PIPE=2 powscript -c<CR>
nmap p> ggVG:!PIPE=2 powscript -c<CR>