Javascript batch processing filename utilities

filename-utils.js

/**
 * Return something as filename-save string. 
 * 
 * Result will contain only 0-9, a-z and "-". 
 * It converts german umlauts, you might want
 * to add some conversions for your target
 * language. 
 */
function filesc(str) {
  return (str+'')
    .toLowerCase()
    .replace('ö','oe')
    .replace('ä','ae')
    .replace('ü','ue')
    .replace('ß','ss')
    .replace(/[^0-9A-Za-z]+/g,'-')
    .replace(/^-|-$/g,'')
  ;
}

/**
 * Pad a number n with c (default:5) zeros. 
 * 
 * For input n=42 returns "00042". 
 */
function zeropad(n,c) {
  n=n*1;
  c=c||5;
  var digits = n==0 ? 1 : Math.floor(Math.log(n)/Math.log(10))+1 ;
  return new Array(c-digits+1).join('0')+n;
}