December 2002
Lynx on OS/2: Straight Answers and Keen Tricks
Part 3 - Viewing Images
by Dallas E. Legan
In parts 1 and 2 of this series, we've concentrated on Lynx and getting it working optimally on your OS/2 system. Now it's time to get creative.
How can I view images with Lynx (or other text mode browsers)?
With REXX!
The build of Lynx that you install may handle image viewing conveniently 'out of the box', but frankly I had to fiddle around some to get it working. I had similar experiences with other text mode browsers I use, in particular eLinks. The following script works with Lynx (or other text mode browsers) and an image viewer (I use PMJPEG, hence the name of the script) so that you can view pictures and other graphics on web pages.
This wrapper script combines all the various measures I found necessary to get PMJPEG working with several text browsers. Comments indicate where it should be put into configuration files/settings to interface with these web clients. Also, it could be used as a place to add some more features, like a menu to select different image viewers/processors. Where these might be added is indicated in comments.
I'm certain people will come up with other ideas to improve this, but it works, and can get you going if have any trouble viewing images!
/* ReXX */
/*
PMGPEGgn.CMD
A wrapper function for general use with text mode browsers
To launch image viewing programs
Usage: pmjpeggn
Make sure /* ReXX */ comment is on the first line,
starting in the first column!
--
Where to use:
Lynx: used in 'lynx.cfg' file
examples:
XLOADIMAGE_COMMAND:pmjpeggn LYNX_TEMP_SPACE %s &
VIEWER:image/bmp:pmjpeggn lynx_temp_space %s &:XWINDOWS
(for Unix type shell)
or
XLOADIMAGE_COMMAND:start /c pmjpeggn LYNX_TEMP_SPACE %s
VIEWER:image/bmp:start /c pmjpeggn lynx_temp_space %s :XWINDOWS
(for CMD.EXE shell)
Also, you should define some none-null value
for environmental variable 'DISPLAY'
either in CONFIG.SYS or a wrapper function being
used to launch Lynx.
Under some circumstances, it may
be used as the image viewer if it is
set to the 'volume:/path/program' being used
as the image viewer.
w3m: used in 'mailcap' file
example:
image/gif ; cmd /c pmjpeggn PWD %s ; ;
eLinks (and probably 'links'): used in escape/setup/associations
(Then escape/setup/save settings)
example, inside text based interface:
c:/os2/apps/pmjpegel PWD %
User will also need to define
extensions and types, 'www image'
'image/jpeg' etc.
--
might typically be:
TMP
TEMP
TMPDIR
LYNX_TEMP_SPACE
PWD
--
typically is '%s' (check browser documentation)
when the link to the image is activated
from the browser, the image is downloaded
to a local file for viewing, but there
seem to be some problems this script will
correct.
*/
/* Grab the command line parameters, by various means: */
PARSE ARG . imagefile ;
PARSE UPPER ARG tdir . ;
/*
CALL SysCls ;
/*
Lip service to loading the RexxUtils until this is really needed.
CALL LOADLIB.CMD
IF RC = 1 THEN SAY "Error: Couldn't load RexxUtil library."
/* FROM "ReXX COOKBOOK", P. 7-2, TO REGISTER ReXXUtil DLL */
*/
*/
/* extract the name of the temporary/scratch directory
typicly stored in the environmental variable whose
name is stored in 'tdir', and was passed to this program
on invocation: */
wdir = Value( tdir, , 'OS2ENVIRONMENT' ) ;
IF '' = wdir THEN
wdir = directory() ;
/* --- for shells where environmental variable
PWD (for instance) might not be defined.
PWD ~ Present Working Directory
pass PWD as a dummy variable if
the browser uses the directory it was
launched in for temporary files,
instead of a directory identified by the value
of an environmental variable.
This last IF statement will then
grab the working directory to use.
*/
/* convert directory seperators to OS/2 standard:
Major purpose of this script - Lynx likes and gives out '/'s
but OS/2 utilities frequently have to have '\'s
as directory seperators.
*/
wdir = Translate( wdir, '\', '/' ) ;
/* now move to the temporary/scratch directory: */
wdirc = Directory( wdir ) ;
/* make the same correction to the image file
directory, if it was part of the name passed
to this script when invoked,
standardizing the directory seperator.
*/
imagefile = Translate( imagefile, '\', '/' ) ;
/* Now extract the file name extension, so the image format
information can be saved:
*/
ofilename = imagefile ;
/*
SAY 'ofilename ='ofilename'=' ;
*/
DO WHILE '' >< ofilename
PARSE VAR ofilename extension '.' ofilename
END
/* SAY 'extension ='extension'=' ; */
newname = 'elqqq.'extension ;
/* SAY 'newname ='newname'=' ; */
/* Note: Possible future improvement:
At this point it might be desirable to ask the user
if they'd like to permenantly save a copy of the
image file, and take appropriate action.
For this possible improvement, the VREXX package
might be a good choice.
*/
/* move the image to another file name because
eLinks browser will immediately delete the
file before pmjpeg.exe (or possibly other image
viewers) get a chance to render the file.
*/
'@ECHO off' ;
'@del 'newname' 2> NUL 1>&2 ' ;
'@Copy 'imagefile' 'newname' 2> NUL 1>&2 ' ;
/* Note: Possible future improvement:
At this point it might be appropriate to ask the user,
with a menu of choices,
what image viewer they would like to use,
For this possible improvement also,
the VREXX package might be a good choice.
*/
/* This is good for all but eLinks, which has a focus problem,
where this flips back to eLinks instead of the image viewer:
'start "Text mode browser Viewer" /F /PM /MAX pmjpeg 'newname ;
(get 'go.exe' or a similar focus/task list tool from Hobbes.)
*/
'@start "Text mode browser Viewer" /F /PM /MAX pmjpeg 'newname ,
' && go -j pmjpeg 2> NUL 1>&2 ' ;
EXIT ;
Try it yourself! You can download a zip file of this script. If your image viewer is something other than PMJPEG, just modify the references in the script appropriately.
To be continued... Part 4 delves into Lynx's EXTERNAL commands with a REXX script that will do a lot of the work for you. The EXTERNAL commands will allow you to switch to another browser (like w3m or eLinks) that can better render framed pages, for example. The image viewer will not help on this. Frame does not necessarily go along with picture in this case!
If you missed them:
- Part 1 of this series gets you started using the Lynx browser.
- Once you have it running, Part 2 helps you use Lynx more effectively.
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