













                                   WAIT

                               V1 18-May-86



Author:  C G Wilson, 71 Galatea St, Charleville, Australia 4470

WAIT is a programme which allows a user to wait until a  particular  period
of  time  has elapsed, or for a particular time on a particular date or day
of the week.

It is designed to be used mostly in command  files  running  detached  jobs
under TSX-plus, but will operate under RT-11.

WAIT requires routines from the CVLLIB library by the  same  author.   This
library is available through DECUS.

Please refer all bugs, complaints and suggestions to the author, who at  an
indefinite time in the future will consider them!


Contents:
        - Running WAIT
        - TIME Format
        - Waiting for a Timed Interval
        - Waiting for a Particular Time
        - Waiting for a Time on a Particular Date
        - Waiting for a Time on a Particular Day of the Week
        -       Special Day Names (TODAY & TOMORROW)
        - After the Wait
        - HELP Text
WAIT - A Programme for Waiting under TSX-plus                        Page 2



1.0  Running WAIT

To run wait, either run it directly (in which case it  will  prompt  for  a
time and optionally a date), or use the DCL format:

        .R WAIT
        Until:
or
        .WAIT <time>

The user must type a time, and optionally a day or date, to WAIT.  The time
should precede the day, and be separated from it by a space:

        .WAIT <time>
        .WAIT <time> <day or date>

        .R WAIT
        Until: <time>

        .R WAIT
        Until: <time> <day or date>




2.0  TIME Format

The time must be specified as digits representing hours, minutes,  seconds,
and clock ticks, in either the form

        hours:minutes:seconds.ticks (optionally followed by AM or PM)

for time or day, or

        +hours:minutes:seconds.ticks

for a time interval.


If not all fields are specified, the first field will be  taken  as  hours,
the second as minutes, et cetera.

For example:

        3:0:0           = 3am
        3:0             = same
        3               = same again

        3pm             = 3pm!
        15:00           = same

        0:0             = midnight, commencing day
        24:0            = midnight, finishing day

WAIT - A Programme for Waiting under TSX-plus                        Page 3



        3:12:25.10      = ten ticks past 25 seconds past
                            twelve minutes past three AM.

        +3              = time interval of three hours
        +0:3            = time interval of three minutes
        +0:0:3          = time interval of three seconds
        +0:0:0.25       = half a second, if 50Hz clock
                            (a bit less if 60Hz)

In interval time (ie preceded by a "+") the hours may exceed 24.  Otherwise
all  fields  are checked for validity.  A time of day of greater than 24:00
(eg 24:30) is not allowed.



3.0  Waiting for a Timed Interval

To wait for a timed interval, specify the time interval required,  preceded
by  a  plus  ("+")  sign.   (You  may  not specify a day or date using this
format.)

        .WAIT +0:10     waits for ten minutes
        .WAIT +0:0:5    waits for five seconds
        .WAIT +100      waits one hundred hours!



4.0  Waiting for a Particular Time

To wait for a particular time, specify the time of day required.

        .WAIT 10:00     waits until the next occurrence of 10am.
        .WAIT 5pm       ibid, 5pm



5.0  Waiting for a Time on a Particular Date

To wait for a particular  time  on  a  particular  date,  follow  the  time
required  by a space, then the date required.  The date may be specified in
standard DEC format (eg 3-Sep-87) or in British format (3/9/87 for the same
date).   If  only  the  day  is  specified,  the current month and year are
assumed.  If the day and the month only are specified, the current year  is
assumed.

        .WAIT 10:00 31-May-86   waits for 10am on that date.
        .WAIT 10:00 31          waits for 10am on the 31st of the current
                                        month.
        .WAIT 10:00 31/5        waits for 10am on the 31st of May this
                                        year.

If the date has already passed, an error message will  be  printed  and  no
waiting will occur.

WAIT - A Programme for Waiting under TSX-plus                        Page 4



There is a limit of about 600 days ahead that WAIT can wait for (due to its
using  only  a single TWAIT request for the complete wait).  If your system
reliability is such that this is a  limitation  (wow!),  use  several  WAIT
commands in a row.



6.0  Waiting for a Time on a Particular Day of the Week

To wait for a particular time on a particular day of the week,  follow  the
time required by a space, then the name of the required day.

        .WAIT 3pm sunday        Waits for the next 3pm on a sunday
                                If today is sunday, and it is not 3pm,
                                it will wait for 3pm today.
        .WAIT 22:00 friday      Waits until the next 10pm on a friday.

        .R WAIT
        Until: 22:00 friday     same
        Until: ^C               (require ^C if run this way)
        .

The day names may be abbreviated to the minimum  non-ambiguous  string  (ie
SU, M, TU, W, TH, F, and SA).



6.1  Special Day Names

There are two special day names implemented:  TODAY  and  TOMORROW.   These
may  not  be  abbreviated.  If a time is specified with TODAY, and the time
has already passed, no wait will occur (unlike specifying the  time  alone,
in  which  case  if  it  has  passed,  WAIT  will  wait until that time the
following day).



7.0  After the Wait

If WAIT is run using the DCL command format (.WAIT time etc), the  keyboard
monitor  will  be  ready  for  another  command  after  the  wait  has been
performed.  If WAIT is run directly (.R WAIT), after the wait the "Until: "
prompt will again be displayed, requiring a control-C to return to monitor.



8.0  HELP Text

The command

        .WAIT help

or      .WAIT
        Until:  help
WAIT - A Programme for Waiting under TSX-plus                        Page 5




will type a brief descriptive text of WAIT functions and formats.
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