Using “showcap” to debug tapecap entries

Doug Tody wrote on Dec 10, 1999

As Tony Ferro points out below there is a bug affecting Exabyte support
in the tapecap.linux file in PC-IRAF which I am passing on in case it
saves someone else from having to debug this as well.  This also shows
how to use the showcap task to debug any *cap file.  (The task certainly
could be made more convenient to use on arbitrary *cap files, but even so
this is easy enough).

----
Hi Tony,

>   I finally tracked down a typo in your dev$tapecap.linux file in the
>   RedHat PCIX distribution.  The "mtexb?" entries end in "tc=generic-exabyte"
>   instead of "tc=generic-exb" which is the actual entry lower on.  With
>   this change the drive is at least recognized.

This has been fixed in the master system, thanks.
 
>   Is there any utility similar to the showcap program for graphcap which
>   will display the "expanded" tapecap entry?  That would have helped debug
>   this problem.

It isn't very apparent but showcap is in fact what you use for all the "cap"
files.  For example in the current case I just did this and here is what
it looks like:

    cl> set graphcap = dev$tapecap.linux
    cl> 
    cl> showcap
    cmd :  `set' device
	|  `*' (to dump full graphcap entry
	|  cc [arg1 [arg2 [arg3]]]
	;

    cc  :   a two chararacter capcode (e.g., 'cm')
	|   an encoder program (non alpha first char)
	;

    * set mtexb0
    :al=st0 nst0:dv=nst0:lk=st0:dt=Exabyte EXB-8200 8mm tape drive:\
    tt=P6-120MP:ts#2347794:bs#0:mr#32768:or#32768:fb#10:rs#2000:fs#188416:\
    mf:

An extra "cl" before the above, followed by a "bye" when done, would
remove the temporary redefinition of graphcap.

	- Doug

---

Last post on Dec 10, 1999