From:	HENRY::IN%"munnari!murdu.oz!u3369429%seismo.css.gov%sri-kl.ARPA%relay.cs.net@rca.com" 17-FEB-1987 09:06
To:	
Subj:	Re: A Useful 'SET DEFAULT' Replacement

In article <8702131859.AA01619@blia.BLI> forrest@cgl.ucsf.edu@blia.UUCP (Jon Forrest) writes:
>The following is a command procedure that replaces the
>'SET DEFAULT' command. There have been many versions
>of such command procedures, 
My hot favourite is "SD" by Richard L.Bryan, Stan Knutson, Vicki, Tom Kent
and Alan L. Zirkle. Beats everything I've seen so far.

>The primary feature of my version is that it
>sets your prompt to the complete default directory name.
Don't you get into difficulties if the length of your current directory string
is greater than 32 characters?

I use my prompt-string for two different things:
A "$$ " indicates that my privileges are switched on, a "# " indicates that they
are disabled.
When I also wanted to include the "current directory" in my prompt, I found it
very inconvenient to look for the cursor all over the screen. I like things to
be predictable. So I came up with a prompt string which displays the directory
on the far right, while the usual prompt ({"$$ "|"# "}) appears on the left.

The resulting procedure ("PCD") is called by my version of "cd" ("SD", see
above). Here it is:
 
$ Verify='F$Verify(F$TRNLNM("COMMAND_DEBUG"))
$! Procedure: PCD.COM  V-1.24  Michael Bednarek  November 1986
$! Sets prompt to Current Directory/CR/Previous Prompt
$! It produces a 32 character prompt string with the directory as far to the
$! right as possible, positioning the cursor however after the 'previous prompt'
$! This can result in a strange appearance with long directory names; never
$! mind, just type over it.
$ CR[0,8]=13					! Carriage Return
$ TAB[0,8]=9					! Horizontal Tab
$ Old_Prompt=F$Environment("Prompt")
$ pCR=F$Locate(CR,Old_Prompt)			! position of <CR> in Old_Prompt
$ If pCR.eq.F$Length(Old_Prompt) then pCR=-1
$ Prompt=F$Extract(pCR+1,255,Old_Prompt)	! part of Old_Prompt after <CR>
$ lP=F$Length(Prompt)				! length thereof
$ Directory=F$Environment("DEFAULT")
$ lD=F$Length(Directory)
$ If lP+lD.le.31 then goto Do_it
$! If the length of the part of OLD_Prompt that we want to retain (lP) plus
$! the length of the current directory is greater than 31 we extract the
$! rightmost part of the directory string.
$ x=31-lP
$ Directory=F$Extract(lD-30+lP,x,Directory)
$ lD=x
$ Do_it: n=31-lD-lP	! n indicates the number of <TAB>s we can insert
$ If n.lt.0 then n=0
$ If n*8+lD.gt.80 then n=(80-lD)/8	! but don't make it fall off the screen
$!Prompt=F$FAO("!''n'*	")+Directory+CR+Prompt
$ Prompt=F$FAO("!''n'*''TAB'")+Directory+CR+Prompt
$!
$ Set Prompt="''Prompt'"
$ Verify=F$Verify(Verify)

u3369429@murdu.oz.au (Michael Bednarek)