jayin

  

Let's say you have a gitignore-like file:

# https://github.com/fritx/dotfiles
# .gitignore
*
!.gitignore
!README.md
!prs-welcome.svg
!.bashrc
!.bash_profile
!.exports
!.aliases
!.editorconfig

You want to cp the listed files to another folder.

Do it in bash?

files=$(cat .gitignore | sed /^\*$/d | sed s/\!//)
for file in $files; do cp $file ./dotfiles/; done
 
# or even 
cat file | sed /^\*$/d | sed s/\!// \
  | while read -r file; do cp $file ./dotfiles/; done
 
# thanks to @congeec, http://v2ex.com/t/278831#reply3 
sed /^\*$/d .gitignore | sed s/\!// | xargs -I{} cp {} ./dotfiles/

WTF?

As a node.js developer, what if using just js flow/style?

cat .gitignore | js -ti 'x.trim().split(`\n`).slice(1).map(x => x.slice(1))' \
  | js -e 'exec(`cp ${x} ./dotfiles/`)'
 
# same as 
cat .gitignore | js -ti 'x.trim().split(`\n`)' \
  | js 'x.slice(1)' \
  | js 'x.map(x => x.slice(1))' \
  | js -e -c 'cp ${x} ./dotfiles/'

# lodash is also integrated in 
# https://github.com/lodash/lodash 
echo '[1,2,3,4]' | js '_.filter(x, x => x %2)'  \
  | js '_.reverse(x)'  \
  >> file
 
# or in chain 
echo '[1,2,3,4]'  \
  | js '_(x).filter(x => x %2).reverse().value()'  \
  >> file

Don't forget to take an alias if you want.

npm install -g jayin
alias js="jayin"

• -ti: input as text, no more JSON.parse
• -to: output as text, no more JSON.stringify
• -t: input/output both as text
• -e: for each, in chain
• -c: shortcut of exec(cmd)
• x: current input value
• i: current index value (with -e)
• exec(cmd): child_process.execSync(cmd)

jayin is based on through2.

If you've seen anything that is similar to this, don't hesitate to let me know ;)