function sprintf() {
    function pad(str, len, chr, leftJustify) {
        var padding = (str.length >= len) ? '' : Array(1 + len - str.length >>> 0).join(chr);
        return leftJustify ? str + padding : padding + str;

    }

    function justify(value, prefix, leftJustify, minWidth, zeroPad) {
        var diff = minWidth - value.length;
        if (diff > 0) {
            if (leftJustify || !zeroPad) {
                value = pad(value, minWidth, ' ', leftJustify);
            } else {
                value = value.slice(0, prefix.length) + pad('', diff, '0', true) + value.slice(prefix.length);
            }
        }
        return value;
    }

    function formatBaseX(value, base, prefix, leftJustify, minWidth, precision, zeroPad) {
        // Note: casts negative numbers to positive ones
        var number = value >>> 0;
        prefix = prefix && number && {'2': '0b', '8': '0', '16': '0x'}[base] || '';
        value = prefix + pad(number.toString(base), precision || 0, '0', false);
        return justify(value, prefix, leftJustify, minWidth, zeroPad);
    }

    function formatString(value, leftJustify, minWidth, precision, zeroPad) {
        if (precision != null) {
            value = value.slice(0, precision);
        }
        return justify(value, '', leftJustify, minWidth, zeroPad);
    }

    var a = arguments, i = 0, format = a[i++];
    return format.replace(sprintf.regex, function(substring, valueIndex, flags, minWidth, _, precision, type) {
            if (substring == '%%') return '%';

            // parse flags
            var leftJustify = false, positivePrefix = '', zeroPad = false, prefixBaseX = false;
            for (var j = 0; flags && j < flags.length; j++) switch (flags.charAt(j)) {
                case ' ': positivePrefix = ' '; break;
                case '+': positivePrefix = '+'; break;
                case '-': leftJustify = true; break;
                case '0': zeroPad = true; break;
                case '#': prefixBaseX = true; break;
            }

            // parameters may be null, undefined, empty-string or real valued
            // we want to ignore null, undefined and empty-string values

            if (!minWidth) {
                minWidth = 0;
            } else if (minWidth == '*') {
                minWidth = +a[i++];
            } else if (minWidth.charAt(0) == '*') {
                minWidth = +a[minWidth.slice(1, -1)];
            } else {
                minWidth = +minWidth;
            }

            // Note: undocumented perl feature:
            if (minWidth < 0) {
                minWidth = -minWidth;
                leftJustify = true;
            }

            if (!isFinite(minWidth)) {
                throw new Error('sprintf: (minimum-)width must be finite');
            }

            if (!precision) {
                precision = 'fFeE'.indexOf(type) > -1 ? 6 : (type == 'd') ? 0 : void(0);
            } else if (precision == '*') {
                precision = +a[i++];
            } else if (precision.charAt(0) == '*') {
                precision = +a[precision.slice(1, -1)];
            } else {
                precision = +precision;
            }

            // grab value using valueIndex if required?
            var value = valueIndex ? a[valueIndex.slice(0, -1)] : a[i++];

            switch (type) {
                case 's': return formatString(String(value), leftJustify, minWidth, precision, zeroPad);
                case 'c': return formatString(String.fromCharCode(+value), leftJustify, minWidth, precision, zeroPad);
                case 'b': return formatBaseX(value, 2, prefixBaseX, leftJustify, minWidth, precision, zeroPad);
                case 'o': return formatBaseX(value, 8, prefixBaseX, leftJustify, minWidth, precision, zeroPad);
                case 'x': return formatBaseX(value, 16, prefixBaseX, leftJustify, minWidth, precision, zeroPad);
                case 'X': return formatBaseX(value, 16, prefixBaseX, leftJustify, minWidth, precision, zeroPad).toUpperCase();
                case 'u': return formatBaseX(value, 10, prefixBaseX, leftJustify, minWidth, precision, zeroPad);
                case 'i':
                case 'd': {
                              var number = parseInt(+value);
                              var prefix = number < 0 ? '-' : positivePrefix;
                              value = prefix + pad(String(Math.abs(number)), precision, '0', false);
                              return justify(value, prefix, leftJustify, minWidth, zeroPad);
                          }
                case 'e':
                case 'E':
                case 'f':
                case 'F':
                case 'g':
                case 'G':
                          {
                              var number = +value;
                              var prefix = number < 0 ? '-' : positivePrefix;
                              var method = ['toExponential', 'toFixed', 'toPrecision']['efg'.indexOf(type.toLowerCase())];
                              var textTransform = ['toString', 'toUpperCase']['eEfFgG'.indexOf(type) % 2];
                              value = prefix + Math.abs(number)[method](precision);
                              return justify(value, prefix, leftJustify, minWidth, zeroPad)[textTransform]();
                          }
                default: return substring;
            }
                    });
}
sprintf.regex = /%%|%(\d+\$)?([-+#0 ]*)(\*\d+\$|\*|\d+)?(\.(\*\d+\$|\*|\d+))?([scboxXuidfegEG])/g;

/**
 * Trival printf implementation, probably only useful during page-load.
 * Note: you may as well use "document.write(sprintf(....))" directly
 */
function printf() {
    // delegate the work to sprintf in an IE5 friendly manner:
    var i = 0, a = arguments, args = Array(arguments.length);
    while (i < args.length) args[i] = 'a[' + (i++) + ']';
    document.write(eval('sprintf(' + args + ')'));
}