Command Wait in COBOL? - cobol

Question

Is there a kind of "Wait" function in COBOL?
I wrote a calculator, and to make it more 50s, i Print " Computing." "Computing.." ecc
For example:
DISPLAY "SECONDO NUMERO"
ACCEPT B
COMPUTE C= A * B
DISPLAY "Computing"
DISPLAY "Computing."
DISPLAY "Computing.."
DISPLAY "Computing..."
DISPLAY "Computing...."
DISPLAY "Computing....."
DISPLAY "Computing......"
DISPLAY A "x" B " FA..."
DISPLAY C
Now, is there a way to make a little delay (half a second) on COBOL where I put the "Computing" piece? I created a github repo (https://github.com/aIDserse/Super-utility-Submachine-COBOL-CALCULATOR) to this project, look at it (refer to version 1.3) for the complete code (and maybye spread it hahah). Thx!!!

Answer 1

There is a statement for sleeping in standard COBOL, but only with COBOL 202x:
CONTINUE AFTER arithmetic-expression SECONDS
As this standard is in the committee draft state it is hard to find an implementation, but as you've asked for GnuCOBOL - GnuCOBOL 3.1 already implements it.
Other than this there are some dialect specific library routines that can be used, like CALL "C$SLEEP" originating from ACUCOBOL-GT (also implemented with GnuCOBOL, but be aware that pre 3.1-versions only use the non-decimal part, so "0.9" will sleep zero seconds).
For OpenCOBOL/GnuCOBOL you can call the CBL_OC_NANOSLEEP/CBL_GC_NANOSLEEP library routines.
For any COBOL environment that can call native routines you have variants of CALL "sleep".
As mentioned by Rick Smith Many COBOL implementations also implement a callable SYSTEM where you may use something like a ping localhost with a timeout, but whatever you call may not be available (or the process running the COBOL environment has no access to it).
Stephen Gennard mentioned a very common extension:
ACCEPT something WITH TIMEOUT
which has a "beware" that different environments use a different scale (some seconds, some milliseconds). This has the pro/con that the user can "break" out by pressing a key (normally a function key); and the additional issue that it may only work in "graphical" environments.
Anton's answer highlights the IBM library routine CEE3DLY.

Answer 2

There's no wait statement in any ISO Standard COBOL.
However, if you got built in system routines available either C$SLEEP (for seconds) or CBL_GC_NANOSLEEP (for nanoseconds) should do the trick.
Example (sleeps for half a second):
call "CBL_GC_NANOSLEEP" using "500000000" end-call
For IBM's Enterprise COBOL (LE enabled) the CEE3DLY routine is most suitable (there are also other legacy routines available).

Answer 3

For GnuCobol call the C$SLEEP with the number of seconds you want to wait.
CALL "C$SLEEP" USING 2 END-CALL
COBOL has no build in language feature to handle waiting. This is a system specific request and I believe always requires calling an external module to interface with said system.

Answer 4

There is no wait or delay statement in standard COBOL. There may be, for GnuCOBOL, a CALL "SYSTEM" to effect a delay.
I took some code that I use for elapsed time measurement and modified the code to create a procedure for a delay.
Wherever you need a delay, insert the statement PERFORM timed-delay. Of course, the delay may be changed. This code is set to work even if the delay crosses midnight.
Code:
working-storage section.
01 t pic 9(8).
01 t-start.
03 t-start-hour pic 99.
03 t-start-minute pic 99.
03 t-start-second pic 99v99.
01 t-end.
03 t-end-hour pic 99.
03 t-end-minute pic 99.
03 t-end-second pic 99v99.
77 t-elapsed pic 9(7)v99.
procedure division.
begin.
accept t from time
display t
perform timed-delay
accept t from time
display t
stop run
.
timed-delay.
accept t-start from time
move 0 to t-elapsed
perform until t-elapsed > 0.5 *> one-half second
accept t-end from time
perform get-elapsed
end-perform
.
get-elapsed.
if t-start > t-end
move 86400 to t-elapsed
else
move 0 to t-elapsed
end-if
compute t-elapsed = t-elapsed
+ (t-end-hour - t-start-hour) * 3600
+ (t-end-minute - t-start-minute) * 60
+ (t-end-second - t-start-second)
end-compute
.
Output: (shows a delay of 0.55 seconds)
21424364
21424419
The initial PERFORM WITH TEST AFTER ... is nothing like the code I provided in: Cobol-Restart from the program , so I turned it into comments. It should be removed.
If you want to use SLEEP-SEC instead of a fixed value, replace the 0.5 with SLEEP-SEC; but provide a VALUE clause for SLEEP-SEC or MOVE a value to it before the displaying the menu.
For example, in your code (with most code removed):
DATA DIVISION.
WORKING-STORAGE SECTION.
01 SLEEP-SEC PIC S9(2)V9(2).
01 A PIC S9(7)V9(7).
01 B PIC S9(7)V9(7).
01 C PIC S9(7)V9(7).
01 D PIC S9(11)V9(7).
01 INPUT1 PIC 9(14).
01 Q PIC X VALUE "Y".
01 t-start.
03 t-start-hour pic 99.
03 t-start-minute pic 99.
03 t-start-second pic 99v99.
01 t-end.
03 t-end-hour pic 99.
03 t-end-minute pic 99.
03 t-end-second pic 99v99.
77 t-elapsed pic 9(7)v99.
PROCEDURE DIVISION.
MAIN.
* PERFORM WITH TEST AFTER
* UNTIL Q ="YES" OR "Y" OR "y" OR "yes" OR "Yes"
* END-PERFORM.
DISPLAY "CALCULATOR".
DISPLAY "WHAT DO YOU WANT DO DO?".
DISPLAY "1 ADDITION".
DISPLAY "15 EXIT"
DISPLAY "CHOOSE AN OPTION"
ACCEPT INPUT1
EVALUATE INPUT1
WHEN = 15
DISPLAY "OK, GOOD JOB :)"
STOP RUN
WHEN = 1
DISPLAY "FIRST NUMBER"
ACCEPT A
DISPLAY "SECOND NUMBER"
ACCEPT B
COMPUTE C= A + B
DISPLAY "Computing"
PERFORM timed-delay
DISPLAY "(" A ")" "+" "(" B ")" "RESULTS..."
DISPLAY C
END-EVALUATE
IF INPUT1 NOT = 15
DISPLAY "DO YOU WANT TO DO OTHER CALCULATIONS?"
ACCEPT Q
IF Q = "YES" OR "Y" OR "y" OR "yes" OR "Yes" GO TO MAIN
ELSE DISPLAY "OK, GOOD JOB :)"
END-IF
STOP RUN.
timed-delay.
accept t-start from time
move 0 to t-elapsed
perform until t-elapsed > 0.5 *> one-half second
accept t-end from time
perform get-elapsed
end-perform
.
get-elapsed.
if t-start > t-end
move 86400 to t-elapsed
else
move 0 to t-elapsed
end-if
compute t-elapsed = t-elapsed
+ (t-end-hour - t-start-hour) * 3600
+ (t-end-minute - t-start-minute) * 60
+ (t-end-second - t-start-second)
end-compute
.