The Gz plugin for the GIMP

This is a quick and dirty page that is the semi-definitive reference on the gzip plugin for the Gimp. I apologize for the lack of gimp graphics. The source is gz.c.

As of 4 Oct 1997, I've updated the plugin to understand file magic. As soon as I remember my author-password to the plugin registry, I'll update it in the registry, and I'm sure the changes will get worked into the next Gimp release. The changes I made should also be made to the bzip2 plugin, which should happen soon.

As of Gimp 0.99.10, Gz comes standard and works correctly without patches to the application. I don't know of any bugs with this version.

As of 30 May 1997, I uploaded to the plugin registry an updated version of gz that is less likely to overwrite files when the indirect save method fails.

Under earlier versions of the Gimp (0.99.9 and below), gz didn't work correctly without patches to the Gimp application itself. If you are running versions this old, upgrade.

Gz is no longer in active development, and I have received no bug reports since it's release. It appears to be stable. Nevertheless, if you have constructive feedback, let me know.

Other notes

• The module works by saving or decompressing to temporary files. This means that you need to have enough free space to have the uncompressed image around momentarily while loading or saving a compressed image. The design of file plugins makes this unavoidable without using named pipes, which I'm not sure can be done in a sufficiently portable way, and would also require modifications to the Gimp application.
• Here's the original comment:

  /* gzip plug-in for the gimp */
  /* loosley based on url.c */ 
  
  /* and, very loosely on hrz.c by */
  /* Albert Cahalan <acahalan at cs.uml.edu> */
  
  /* This is reads and writes gziped image files for the Gimp
   * 
   * You need to have gzip installed for it to work.
   *
   * It works, but I suppose it should be tested more.
   * considering I finshed it at 4:20 in the morning.  
   *
   * It should work with file names of the form
   * filename.foo.gz where foo is some already-recognized extension
   * 
   * and it also works for names of the form 
   * filename.xcfgz - which is equivalent to 
   * filename.xcf.gz
   *
   * I added the xcfgz bit because having a default extension of xcf.gz
   * can confuse the file selection dialog box somewhat, forcing the
   * user to type sometimes when he/she otherwise wouldn't need to.
   *
   * I later decided I didn't like it because I don't like to bloat
   * the file-extension namespace.  But I left in the recognition
   * feature/bug so if people want to use files named foo.xcfgz by
   * default, they can just hack their pluginrc file.
   * 
   * to do this hack, change :
   *                      "xcf.gz,gz,xcfgz"
   * to
   *                      "xcfgz,gz,xcf.gz"
   * 
   * 
   * -Dan Risacher, 0430 CDT, 26 May 1997
   */