Re: LYNX-DEV lynx.cfg VIEWER entry which crashes lynx

[Klaus Weide]

On Sat, 30 Nov 1996, Nelson Henry Eric wrote:

> In my futile attempts to view a compressed text file via most in
> lynx, I hit upon a way to crash lynx.  Using lynx2-6 with the
> 11/24 composite, slang0.99-34,  compiled with gcc-2.7.2 on sunos4.1.3.
> Don't know if it's interesting or not.  Particulars below.  __Henry
> 
> With the entry in lynx.cfg:
> 
> VIEWER:text/x-compressed:/usr/bin/gzip %s > ~/%s | /home/.most/most ~/%s

Just

VIEWER:text/x-compressed:/home/.most/most %s
 
should do, since the file that your VIEWER gets to see will have
already been uncompressed at that point.  The first %s will be the
name of a temporary file into which Lynx uncompresses your original
file.  And your trace shows that that is happening.

One should never put more %s's in the definitions in lynx.cfg than 
are supported; i.e. (according to the comments in lynx.cfg) two for
DOWNLOADER and PRINTER, one for some others. 

Your crash is probably due do this statement from src/HTFWriter.c:

    sprintf (me->end_command, pres->command, fnam, "");

where pres->command will hold the string you specified as a viewer
command.  A second %s in that string would in effect be ignored,
but the third on makes sprintf() try to handle more aguments than it has..

It's not nice of Lynx to crash in such a case, but at least it is not
something that can be done by a user of a captive account (but only 
by the installer of the .cfg file, and maybe the mailcap file).

Some warning text in lynx.cfg might be in order..

  Klaus

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