File renaming code

[xbytor]

I've been working with exiftool a lot lately. One of the things I like about it is the way it can convert file names. If you've done any C programming, it's basically a sprintf-technique.

This function makes it brain-dead easy to get the base and extension of a filename
Code: Select allvar base = file.strf("%f");
var ext= file.strf("%e")

change a file's extension
Code: Select allvar fname  = file.strf("%d/%f.psd");

and create completely new path names based on the old one
Code: Select allvar fname = file.strf("%d/%e/%f.%e);

I do stuff like this manually on a regular basis. Now there's a way to do it automagically.

Let me know if you find any problems.

Enjoy!

-X

Code: Select all//
// File.strf
//   This is based of the file name formatting facility in exiftool. Part of
//   the description is copy directly from there. You can find exiftool at:
//      http://www.sno.phy.queensu.ca/~phil/exiftool/
//
// Description:
//
//   Format a file string using a printf-like format string
//
//
// fmt is a string where the following substitutions occur
//   %d - the directory name (no trailing /)
//   %f - the file name without the extension
//   %e - the file extension without the leading '.'
//   %% - the '%' character
//
// if fs is true the folder is in local file system format
//   (e.g. C:\images instead of /c/images)
//
// Examples:
//
// Reformat the file name:
// var f = new File("/c/work/test.jpg");
// f.strf("%d/%f_%e.txt") == "/c/work/test_jpg.txt"
//
// Change the file extension
// f.strf("%d/%f.psd") == "/c/work/test.psd"
//
// Convert to a file name in a subdirectory named after the extension
// f.strf("%d/%e/%f.%e") == "/c/work/jpg/test.jpg"
//
// Change the file extension and convert to a file name in a subdirectory named
//   after the new extension
// f.strf("%d/psd/%f.psd") == "/c/work/psd/test.psd"
//
// Advanced Substitution
//   A substring of the original file name, directory or extension may be
//   taken by specifying a string length immediately following the % character.
//   If the length is negative, the substring is taken from the end. The
//   substring position (characters to ignore at the start or end of the
//   string) may be given by a second optional value after a decimal point.
//
// For example:
//
// var f = new File("Picture-123.jpg");
//
// f.strf("%7f.psd") == "Picture.psd"
// f.strf("%-.4f.psd") == "Picture.psd"
// f.strf("%7f.%-3f") == "Picture.123"
// f.strf("Meta%-3.1f.xmp") == "Meta123.xmp"
//
File.prototype.strf = function(fmt, fs) {
  var self = this;
  var name = self.name;

  var m = name.match(/\.([^\.]+)/);
  var e = m ? m[1] : '';
  m = name.match(/(.*)\.[^\.]+/);
  var f = m ? m[1] : name;
  var d = (fs ? self.parent.fsName : self.parent.toString());

  var str = fmt;

  if (false) {
    // simple substitution
    var str = str.replace(/%d/g, d);
    str = str.replace(/%f/g, f);
    str = str.replace(/%e/g, e);
    str = str.replace(/%%/g, '%');
  }

  // advanced substition

  var rex = /([^%]*)%(-)?(\d+)?(\.\d+)?(%|d|e|f)(.*)/;


  while (m = rex.exec(str)) {
    var pre = m[1];
    var sig = m[2];
    var len = m[3];
    var ign = m[4];
    var typ = m[5];
    var post = m[6];

    var subst = '';

    if (typ == '%') {
      subst = '%';
    } else {
      var s = '';
      switch (typ) {
        case 'd': s = d; break;
        case 'e': s = e; break;
        case 'f': s = f; break;
      }

      var strlen = s.length;

      if (len || ign) {
        ign = (ign ? Number(ign.substr(1)) : 0);
        if (len) {
          len = Number(len);
          if (sig) {
            subst = s.substr(strlen - len - ign, len);
          } else {
            subst = s.substr(ign, len);
          }
        } else {
          if (sig) {
            subst = s.substr(0, strlen-ign);
          } else {
            subst = s.substr(ign);
          }
        }

      } else {
        subst = s;
      }
    }

    str = pre + subst + post;
  }

  return str;
};

[rogerdodger]

was looking how to rename files and just found this.

thanks again!