text: var common = require('./common');
  var fs = require('fs');
  
  // add c spaces to the left of str
  function lpad(c, str) {
      var res = '' + str;
      if (res.length < c) {
          res = Array((c - res.length) + 1).join(' ') + res;
      }
      return res;
  }
  
  common.register('uniq', _uniq, {
      canReceivePipe: true,
      cmdOptions: {
          'i': 'ignoreCase',
          'c': 'count',
          'd': 'duplicates',
      },
  });
  
  //@
  //@ ### uniq([options,] [input, [output]])
  //@ Available options:
  //@
  //@ + `-i`: Ignore case while comparing
  //@ + `-c`: Prefix lines by the number of occurrences
  //@ + `-d`: Only print duplicate lines, one for each group of identical lines
  //@
  //@ Examples:
  //@
  //@ ```javascript
  //@ uniq('foo.txt');
  //@ uniq('-i', 'foo.txt');
  //@ uniq('-cd', 'foo.txt', 'bar.txt');
  //@ ```
  //@
  //@ Filter adjacent matching lines from input
  function _uniq(options, input, output) {
      // Check if this is coming from a pipe
      var pipe = common.readFromPipe();
  
      if (!input && !pipe) common.error('no input given');
  
      var lines = (input ? fs.readFileSync(input, 'utf8') : pipe).trimRight().split(/\r*\n/);
  
      var compare = function (a, b) {
          return options.ignoreCase ?
              a.toLocaleLowerCase().localeCompare(b.toLocaleLowerCase()) :
              a.localeCompare(b);
      };
      var uniqed = lines.reduceRight(function (res, e) {
              // Perform uniq -c on the input
              if (res.length === 0) {
                  return [{count: 1, ln: e}];
              } else if (compare(res[0].ln, e) === 0) {
                  return [{count: res[0].count + 1, ln: e}].concat(res.slice(1));
              } else {
                  return [{count: 1, ln: e}].concat(res);
              }
          }, []).filter(function (obj) {
              // Do we want only duplicated objects?
              return options.duplicates ? obj.count > 1 : true;
          }).map(function (obj) {
              // Are we tracking the counts of each line?
              return (options.count ? (lpad(7, obj.count) + ' ') : '') + obj.ln;
          }).join('\n') + '\n';
  
      if (output) {
          (new common.ShellString(uniqed)).to(output);
          // if uniq writes to output, nothing is passed to the next command in the pipeline (if any)
          return '';
      } else {
          return uniqed;
      }
  }
  
  module.exports = _uniq;
  