Contains the implementation of the wc linux command using node.js

wc.js

#!/usr/bin/env node

/*

    This small node.js app should do exactly what the wc linux command does.
    
    Quote from man wc:
         Print  newline,  word,  and  byte counts for each FILE, and a total line if more than one FILE is specified.  With no FILE, or when FILE is -, read standard
       input.  A word is a non-zero-length sequence of characters delimited by white space.  The options below may be used to  select  which  counts  are  printed,
       always in the following order: newline, word, character, byte, maximum line length.
       
   
     In this version I will use the Commander node js extension, please see the https://github.com/visionmedia/commander.js github page.
     Please use the npm install commander command to install the library in your node app folder.

*/

var fs = require('fs');
var commander = require('commander');

var NEW_LINE_DELIMITER = '\n';
var SPACE = ' ';
var TAB = '\t';

var cloneFunction = function(fn) {
    // Workaround for commander.js issue.
    // http://stackoverflow.com/a/6772648
    return fn.bind({});
};


var checkIfFileExists = function(infile) {
    var infilePath = infile.toString();
    var stats = fs.statSync(infilePath);
    if(!stats && !stats.isFile()) {
        process.stdout.write('%s does not exist.', infilePath);                
        process.exit(1);
    }
    return infilePath;
};

var countLines = function(infile) {
    var fileContent = fs.readFileSync(infile);
    if(fileContent) {
        var lineCount = fileContent.toString().split(NEW_LINE_DELIMITER);
        if(lineCount && lineCount.length > 0) {
            var numberOfLines = lineCount.length - 1;
            process.stdout.write(numberOfLines + ' ' + infile +  NEW_LINE_DELIMITER);
        }
        else {
            process.stdout.write('The file is empty.');
        }
    }
    else {
        process.stdout.write('The file is empty.');
    }
};

var countWords = function(infile) {
    var fileContent = fs.readFileSync(infile);
    if(fileContent) {
        var sumOfWords = 0;
        var lines = fileContent.toString().split(NEW_LINE_DELIMITER);
        for(var i=0; i<lines.length ; ++i) {
            if(lines[i] != NEW_LINE_DELIMITER && lines[i] != TAB && lines[i].length > 0) {
                sumOfWords += (lines[i].split(SPACE)).length;            
            }
        }        
        process.stdout.write(sumOfWords + ' ' + infile +  NEW_LINE_DELIMITER);
    }
    else {
        process.stdout.write('The file is empty.');
    }
};

var countCharacters = function(infile) {
    var fileContent = fs.readFileSync(infile);
    if(fileContent) {
        var textInFile = fileContent.toString();
        process.stdout.write(textInFile.length + ' ' + infile +  NEW_LINE_DELIMITER);
    }
    else {
        process.stdout.write('The file is empty.');
    }
};


  commander.option('-l, --lines <file>', 'Path to file to analyze', cloneFunction(checkIfFileExists))
           .option('-w, --words <file>', 'Path to file to analyze', cloneFunction(checkIfFileExists))
           .option('-c, --characters <file>', 'Path to file to analyze', cloneFunction(checkIfFileExists))
           .parse(process.argv);
        
            if(commander.lines) {
                countLines(commander.lines);
            }
            
            if(commander.words) {
                countWords(commander.words);
            }
            
            if(commander.characters) {
                countCharacters(commander.characters);
            }