Zgv is a GIF, JPEG, and PBM/PGM/PPM viewer with a file-selector front-end.

The major changes between v2.2 and the new version are:

- Zgv can now be run from a non-console tty and still work, provided
  there is a free VT available - that is, one without a getty or other
  process running on it. (Generally you'll have at least one or two.)
  If this is required, it switches to the new VT before starting and
  switches back when finished; this gives reasonably transparent
  operation from X, Emacs, iScreen, etc. (Redirect stderr to a
  non-console to force this behaviour when running from consoles -
  e.g. "zgv 2>/dev/null" with bash/ksh/zsh.)

- Scaling mode - allows you to 'zoom in' on a picture and pan around
  the enlarged image. Also available in 'interpolation between the
  enlarged pixels' flavour in 24-bit modes, if you really want your
  computer to crawl... :)

- PgUp, PgDn and similar all do what you might expect now.

- The '-a "command"' option which allows you to use the zgv file
  selection front-end while actually invoking some other program when
  a file is selected for viewing. At the moment, this is a little
  rough around the edges (shell scripts seem to confuse it).

- A couple of other small hacks which might be useful, although they
  aren't strictly the domain of a picture viewer - the '-s' option
  outputs the area of the picture onscreen when Esc is pressed, which
  can be useful in constructions like "djpeg foo.jpg|pnmcut `zgv -s
  foo.jpg` >blarg.ppm"; and the '-r' option to repeatedly re-read a
  picture after a certain timeout.

along with these bugfixes:

- I think I've fixed the 'floating point exception or division by
  zero' problem which several people noted. However, I can't test it,
  so if v2.3 works on your machine and v2.2 didn't, please email me
  saying so.

- A couple of other, more innocuous bugs fixed.

and these other changes:

- Added 'force16fs' entry in config file, to force 16-colour mode for
  file selector. Designed for use if the 256-colour 640x480 mode is
  available from your video card, but for some reason is unusable.

- System config. file is now /etc/zgv.conf. /etc/system.zgvrc still
  works, but it's best to rename it.

- Zgv uses stdin now for keyboard input instead of /dev/tty. (Since
  reading output from another process from stdin in graphics mode
  (along the lines of "djpeg thingy.jpg | zgv /proc/self/fd/0")
  doesn't really work, there was no reason not to; in addition,
  starting up on a free VT would be more tricky otherwise.)

- Zgv is now distributed under the terms of the GNU General Public
  License.


You can find out the current status of zgv and any other free software
by me by fingering mr216@atlas.gre.ac.uk.

Cheers,
- Russell Marks (mr216@gre.ac.uk).