Enhanced SET command
    Copyright (c) 1990 Wayne D. Mingee       All rights reserved
 Archive ESET21  Program ESET v2.1  Suggested donation $10.00

                              QUICK REFERENCE
Formats:
    ESET  switches name prompt [valid-keys] [+/-]length] [time-limit]
    ESET  switches name=[value]

/B terminate if any error has occurred up to this point.
/N terminate if no error has occurred up to this point.
/U convert to upper case.
/C output LF on STDOUT.
/V additional data item is used as valid input chars.
/E the user can edit current value
/M use the master environment
/D display results on stdout as name=value.
/X display return code on stdout as [xxx].
/Lnn the user has nn seconds to start responding.
/A when the user enters a char into the last position input is terminated
/T remove all leading and trailing blanks
Switches UVEMDXTA are toggles. Each occurrence reverses the state.
Special code    $D - returns current date mm-dd-yyyy
                $T - returns current time hh:mm:ss
                $Sn1,n2,string - returns substring of variable
                $+ [+/-]n2 -  add integer n2 to variable
                $& [+/-]n2 -  and integer n2 to variable
                $^ [+/-]n2 -  xor integer n2 to variable
                $[ [+/-]n2 -  shift variable left n2 bits
                $] [+/-]n2 -  shift variable right n2 bits
                $C  - returns a 0 if running under the primary command
                      processor and a 1 if it is a secondary.

If name ends in:       then:
         -             remove data from variable
         ^             prepend data to variable
         +             append data to variable
         *             data is in two parts separated by a
                       delimiter equal to the first char. The
                       first occurrence of the first part is replaced
                       by the second part.
                       ie: /yy/xx/  replaces yy with xx.
         @             same as * but changes all occurrences.