Reviewed and reorganized June 2020
The DO file processor supports various special information variables or built-in macros which take the form $x or $xx, where x is alphabetic. The supported variables are listed here; those that are A-Shell extensions are noted at the end of the list.
|
Variable |
Value |
|
$: |
Original device (e.g. "DSK0:") |
|
$P |
Original ppn (e.g. "7,6") |
|
$$ |
Real dollar sign |
|
$TM |
Time of day in 24 hour HH:MM format (e.g. "13:27") |
|
$TD |
Current date in YYMMDD format |
|
$TW |
Current day of week as a number (0=Mon, 1=Tue,...) |
|
$NJ |
Current job name (e.g. "TSKAAA") |
|
$NT |
Current terminal name |
|
$ND |
Current terminal driver name |
|
$NS |
Current OS (e.g. "AIX") |
|
$SV |
Current OS version |
|
$UX |
Current radix (e.g. "8" or "16") |
|
$LG |
Current language (e.g. "ENGLISH") |
|
$LY |
Yes character (e.g. "Y") |
|
$LN |
No character (e.g. "N") |
|
$NU |
Current login name (e.g. "root") |
The following are supported only under A-Shell:
|
Variable |
Value |
|
$HF |
Current host full path (e.g. "/vm/miame/dsk0/001004") |
|
$HD |
Current host disk (e.g. "dsk0") |
|
$HP |
Current host ppn (e.g. "001004") |
|
$HM |
MIAME env var definition (e.g. "/vm/miame") |
These special information variables are typically used in IF statements or in output messages.
Note that unlike BASIC string symbols defined with the DEFINE statement, these special $ variables in DO files do not contain their own quotes, so if they are used in a context that requires a quoted string, explicit quotes must be added. For example:
IF "$NU" = "jack" ; (correct)
IF $NU = jack ; (incorrect)
IF LEFT("$NJ",3) = "TAS" ; (correct)
IF LEFT($NJ,3) = "TAS" ; (incorrect)
IF "LEFT($NJ,3)" = "TAS" ; (incorrect)
Also note that the special $ variables are only expanded within DO files, not CMD files.