cobol ALTER statement A contrived example using ALTER
Example
identification division.
program-id. altering.
date-written. 2015-10-28/06:36-0400.
remarks. Demonstrate ALTER.
procedure division.
main section.
*> And now for some altering.
contrived.
ALTER story TO PROCEED TO beginning
GO TO story
.
*> Jump to a part of the story
story.
GO.
.
*> the first part
beginning.
ALTER story TO PROCEED to middle
DISPLAY "This is the start of a changing story"
GO TO story
.
*> the middle bit
middle.
ALTER story TO PROCEED to ending
DISPLAY "The story progresses"
GO TO story
.
*> the climatic finish
ending.
DISPLAY "The story ends, happily ever after"
.
*> fall through to the exit
exit program.
With a run sample of
prompt$ cobc -xj -debug altering.cob
This is the start of a changing story
The story progresses
The story ends, happily ever after
prompt$ COB_SET_TRACE=Y ./altering
Source: 'altering.cob'
Program-Id: altering Entry: altering Line: 8
Program-Id: altering Section: main Line: 8
Program-Id: altering Paragraph: contrived Line: 11
Program-Id: altering Statement: ALTER Line: 12
Program-Id: altering Statement: GO TO Line: 13
Program-Id: altering Paragraph: story Line: 17
Program-Id: altering Paragraph: beginning Line: 22
Program-Id: altering Statement: ALTER Line: 23
Program-Id: altering Statement: DISPLAY Line: 24
This is the start of a changing story
Program-Id: altering Statement: GO TO Line: 25
Program-Id: altering Paragraph: story Line: 17
Program-Id: altering Paragraph: middle Line: 29
Program-Id: altering Statement: ALTER Line: 30
Program-Id: altering Statement: DISPLAY Line: 31
The story progresses
Program-Id: altering Statement: GO TO Line: 32
Program-Id: altering Paragraph: story Line: 17
Program-Id: altering Paragraph: ending Line: 36
Program-Id: altering Statement: DISPLAY Line: 37
The story ends, happily ever after
Program-Id: altering Statement: EXIT PROGRAM Line: 41
Program-Id: altering Exit: altering
prompt$
See http://open-cobol.sourceforge.net/faq/index.html#alter for more details.
