Use VarSubtract to subtract a specified value from a specified variable.
VarSubtract may also be entered as VarSubt[ract] or Subt[ract].
Required Operands
OPER1 is the name of a previously declared numeric variable.
OPER2 is a non-negative numeric integer.
OPER2 will be subtracted from the value of the OPER1 variable. The result will be stored in the OPER1 variable. An unconditional error occurs if the result is less than 0.
Return Codes
OK Successful.
Examples
The following example shows how the VarSubtract command could be used within a procedure to search for a string of characters on every third line above the current line:
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SET PPDVBL,1
DCL LINE,NUM,6
DCL STR,CHAR,65,V
PARSE STR
SETD LINE,SSDBASE&SIBSCRPM ;GET CURRENT LINE NUMBER
BLOCK
IF LINE,LE,3 ;ARE THERE 3 LINES LEFT?
EXIT ER,'[9820] String "&STR" not found.'
SUBTRACT LINE,3 ;UP THREE LINES
POSITION &LINE
SET PPDCOND,1 ;EXAMINE USES RETURN CODE
EXAMINE "&STR"
IF SIBRETCD,EQ,OK ;IF WE FOUND IT, GET OUT
EXIT OK
SET PPDCOND,0 ;OTHERWISE TRY AGAIN
ENDBLOCK
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