Troubleshooting Browser Displays of Technical Papers

Problems with Viewing

A properly installed browser will have no problem displaying our technical papers. If things don't work, the problem is at your end. Almost all repositories of computer science papers worldwide use the same file formats that we do, so if you're having trouble here, it'll be the same everywhere else. (Try any of these computer science repositories.) The following notes are intended to help you diagnose the problem. The discussion is in terms of Unix machines. Please mail me corrections if things are different on other machines.

Our technical papers are stored as LaTeX dvi (file extension .dvi) and as postscript files (file extension .ps). Most, but not all papers are available in both formats. Most of the files are compressed with either the Unix "compress" (additional extension .Z) or the GNU "gzip" (additional extension .gz) programs. For the most part, the dvi files use compress (so the extensions become .dvi.Z) and the postscript ones use gzip (with extensions .ps.gz).

To display our papers, you need to have the appropriate programs for undoing the compression ("uncompress" for .Z and "gunzip" for .gz files), and the appropriate viewers (usually "xdvi" for .dvi and "ghostview" or "gv" for .ps), and your browser needs to know which program to apply to which type of file. This is done by various system files, and by a local file which, on Unix machines, is usually called ".mailcap"

First, check whether you can read this plain dvi file and/or this plain postscript file.

If that didn't work, you may either be missing the necessary viewers, or your browser doesn't connect them up to the file extensions correctly.

Using Unix?

Try typing "xdvi", "ghostview", or "gv" directly to a shell. If none of those did anything, then either you don't have the viewers, or they're called something else. In these cases, get your systems guy to tell you what they're called, or to install them. You can get the Ghostview and GV viewers for postscript from http://www.cs.wisc.edu/~ghost/. You'll need ghostscript (the actual postscript interpeter) as well.

Using Windows?

Click here to download the GSview viewer for postscript (it's just over a megabyte). Windows will ask what you want to do with the file--choose the "run this program option". (If you save it to disk, then you'll have to run the downloaded self-installing program gsv34w32.exe yourself.) Click on the GsView icon that appears following the install (or run the program gsview32), which will set up an association with the mime type application/postscript.

Associating Mime Types Correctly

If you have the viewers but things still don't get displayed correctly, then your browser must not be associating them with file extensions correctly. These associations refer to what are called MIME types, and are set up in system files or in the .mailcap file (usually) in your home directory in mailcap format. On Unix, adding the following lines to your .mailcap file will do the job (mutatis mutandis if your viewers are called something else). 
  application/postscript; ghostview %s
  application/x-dvi; xdvi %s
On both Unix and Windows you can also do this easily in Netscape: click on Edit, then Preferences, then Applications (under Navigator). Scroll down to (e.g.,) "application/postscript" in the left hand column and click to select that line. Then click on Edit, then Application. Then browsw to find the Ghostview viewer and click OK, then OK again. Postscript files should now display correctly.

Problems with Decompressing

If you can read the plain dvi and postscript files, then the next thing is to check whether you can read this compressed dvi file and/or this gzipped postscript file.

If not, try typing "uncompress" and "gunzip" directly to a shell. If they don't work, ask your system guy to install these programs, or to tell you what they're called. You can get gzip/gunzip (which can also do uncompress) from the Free Software Foundation at http://www.gnu.org

If the programs are available, then it's probably the associations that are broken. Try adding the following lines to your .mailcap file. 

  application/x-gzip; gunzip %s
  application/x-compress; uncompress %s
You'll never get this to work on Windows or Mac machines because their Web browsers are faulty. Here's an explanation from the Los Alamos National Laboratory. We offer a workaround by decompressing gzipped postscript files locally. (Note that gsview on Windows seems to deal with gzipped files ok.)

Problems with Printing

A4 Paper

Our papers are formatted for 8.5 by 11 inch paper (US letter size) and may look a bit awkward, but should still be readable, on A4. Please mail us at pvs-request@csl.sri.com if any file looks really bad on A4.

You can also resize pages from letter to A4 yourself with the command "psresize -Pletter -pa4" using the psresize program from the psutils package, which you can get from http://www.dcs.ed.ac.uk/home/ajcd/psutils/

Pages Stack in Reverse Order

Most of our papers are stored in acsending page order, which is convenient for printers that stack the pages face down (e.g., HP printers). If your printer does it the other way, use "psrev foo.ps | lpr" or "pstops 1:-0 foo.ps | lpr" to print the pages of foo.ps in reverse order (use "lpr -s" if you run out of spool space).

psrev is distributed as part of Sun or Adobe's software, while pstops is part of the psutils package, which you can get from http://www.dcs.ed.ac.uk/home/ajcd/psutils/ (Another program in the psutils package, called psselect, can also reverse pages and has simpler command arguments.)

Don't try to print from ghostview if the files come out backwards. Either explicitly download and save the file, or grab the temporary file while ghostview is displaying it (this will have a name like hbaa11346.ps in /tmp or /usr/tmp and is deleted once you exit ghostview) and use psrev or pstops as above.

Slow Downloads

Problems with slow downloads aren't our fault. We have a dedicated Web and FTP server directly connnected to the main backbone of the Bay Area Research Net (BARNET), which uses fast routers and numerous redundant T1 and T3 lines. If you're coming in from Europe, try to do so from a country that has adequate external bandwidth (Germany seems particularly bad in this regard), and outside European and US East Coast working hours (I've found things best in the morning, up to about 9am European/8am UK time, and at weekends). Alternatively, try the mirror site in London (this link gets you to .dvi files, postscript files are in a subdirectory of that name)

FTP Access

If all else fails, you can download the files by ftp and deal with them by hand. The ftp directory for dvi files is ftp://ftp.csl.sri.com/pub/reports and that for postscript is ftp://ftp.csl.sri.com/pub/reports/postscript

Return to the Computer Science Laboratory home page

John Rushby (Rushby@csl.sri.com)