nip

    1.1.0 • Public • Published

    nip - Node Input/output Piper

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    nip is a command line utility for performing any type of processing to and from files and pipes

    Install

    npm install nip -g
    

    If you omit the -g then make sure to add the local npm module path to your default path

    You should now be able to call nip from the command line.

    Usage: nip js-function [options] [files]

    The js-function can be one of three syntaxes:

    1. return line.substr(0, 10) + index
    2. function(line, index, cols, lines) { /* code here */ return value; }
    3. /* code */ return function(line, i, cols, lines) { /* ... */ return value; }

    The names line, index, lines, and cols can be changed in the second and third style syntaxes

    If the return value is false nothing is sent to output stream
    If the return value is not a string or number then the line will be sent to the output stream
    else the return value will be sent to the output stream (including an empty string)

    options

    -f js-file or --file=js-file

    use the js-file as the function to execute on the input instead of the js-function argument you must supply either this option or the js-function argument


    -1 or --first-line-only

    only execute once per file, not for each line
    this is useful if you plan on proccessing the file as a whole, namely through the lines variable
    for example (not a useful one): nip 'return lines.length' -1 file.txt


    -c string-or-regex, --col-splitter=string-or-regex

    the splitter for --cols, can be regex or string format, by default it's /\s+/


    -s string-or-regex, --line-splitter=string-or-regex

    the line separator, can be regex or string format, by default we're splitting on lines so it's \n


    -n string, --line-joiner=string

    string used to join lines together


    Examples

    Only output lines that begin with the word var:

    nip 'function(l) { return /^var/.test(l); }' lines-that-start-with-var.txt
    

    Output every second line only in uppercase in a file:

    nip 'function(line, i) { return i % 2 ? line.toUpperCase() : false; }' every-2nd-line.txt
    

    Trim whitesplace from a file:

    nip 'return line.replace(/^s*|s*$/g, "");' trim-lines.txt
    

    Run the contents of jsfile.js on file.txt:

    nip -f jsfile.js file.txt
    

    Like most unix commands, you can pipe the input and/or output:

    generate a script file to rename files recursively and sequentiality
    find . -type f | nip 'return "mv " + line + " " + line.replace(/\/[^/]*$/, "") + "/" + index;' > rename-script

    rename files recursively and sequentiality
    find . -type f | nip 'return "mv " + line + " " + line.replace(/\/[^/]*$/, "") + "/" + index;' | sh

    find the biggest number from all files in a directory:

    nip '
      var biggest = 0;
      this.on("end", function() { print(biggest); });
      return function(_,i,lines) {
        biggest = Math.max(biggest,
          Math.max.apply(Math, lines.match(/(?:\s|^)[\d]+(?:\.\d*)?(?:\s|$)/g))
        )
      }' -1 *
    

    By default there are start, end, fileStart, and fileEnd events you can register by doing this.on('end', function() {})

    The context inside the main function can be used as a global store, and has a filename property


    Why

    This is for people who aren't "devops" and who can't crank out a fancy piped shell script using awk and sed. Also most programmers who have node installed can write a quick javascript one+ liner to do what the oldschoolers would make a shell script out of.

    https://github.com/kolodny/nip

    Install

    npm i nip

    DownloadsWeekly Downloads

    2

    Version

    1.1.0

    License

    MIT

    Unpacked Size

    13.6 kB

    Total Files

    13

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