d $!{DO}	TREE {? or name or .name or [dir.sub...]}
È $!		Moves user around is sub-directory structure.
,$!
$! Enter $	{DO} TREE ?    		Show the next levels
ô$! Enter $	{DO} TREE (RET)		Remove an entry
X$! Enter $	{DO} TREE name 		Add an entry
¼$! Enter $	{DO} TREE .name		Replace lowest entry
 $! Enter $	{DO} TREE {DRxx:}{[...{]}}	SET DEF ...
„$!
è$!-end.of.info-
L$
~$ sds := 'f$logical("SYS$DISK")
°$ old := 'f$directory()
$ leng = 'f$length(old)-1
x$ if( p1.nes."?" ) then goto notnxt
Ü$	do dir *.dir .
@$	exit
¤$
$notnxt:
l$ if( 'f$locate(":",p1).eq.'f$lenght(p1) ) then goto notdrxx
Ð$	if( 'f$locate("[",p1).eq.'f$length(p1)) then p1:= 'p1''old'
4$	goto setdir
˜$
ü$notdrxx:
`	$ if( 'f$locate("[",p1).eq.'f$length(p1) ) then goto notset
Ä	$setdir:
(
$	if( 'f$locate("]",p1).eq.'f$length(p1) ) then p1 := 'p1']
Œ
$	newdir := 'p1
ð
$	goto nowdo
T$
¸$notset:
$ if( p1 .nes. "" ) then goto notup
€$
ä$up:
H$ if( "''f$extract( leng,1,old )'".eqs."." ) then goto gotit
¬$ leng = leng-1
$	if( leng.gt.1 ) then goto up
t$		newdir := 'old'
Ø$		goto nowdo
<$gotit:
 $ newdir := 'f$extract(0,leng,old)']
$	goto nowdo
h$notup:
Ì$ if( "''f$extract( 0,1,p1)'".nes."." ) then goto down
0$	p1 := 'f$extract(1,100,p1)
”$notyet:
ø$ if( "''f$extract( leng,1,old )'".eqs."." ) then goto down
\$ leng = leng-1
À$	if( leng.gt.1 ) then goto notyet
$$		newdir := 'old'
ˆ$		goto nowdo
ì$down:
P$ newdir := 'f$extract(0,leng,old)'.'p1']
´$
$nowdo:
|$ write sys$output "$  set def ",newdir," ,from ",sds,old
à$ set def 'newdir'