HP 3000 Manuals HP 3000 Manuals
IF
Used to control the execution sequence of a job, UDC, or command file.
(Native Mode)
Syntax
IF expression [THEN]
Parameters
expression Logical expression, consisting of operands and
relational operators. The operators listed in
table 2-14 may be incorporated in expression.
Table 2-14. Logical Operators - The IF Command
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| | |
| Logical operators: | AND, OR, XOR, NOT |
| | |
- -
| | |
| Boolean functions and values: | BOUND, TRUE, FALSE, ALPHA, ALPHANUM, NUMERIC, ODD |
| | |
- -
| | |
| Comparison operators: | =, <>, <, >, <=, >= |
| | |
- -
| | |
| Bit manipulation operators: | LSL, LSR, CSR, CSL, BAND, BOR, BXOR, BNOT |
| | |
- -
| | |
| Arithmetic operators: | MOD, ABS, * , / , + , -, ^ (exponentiation) |
| | |
- -
| | |
| Functions returning strings: | CHR, DWNS, UPS, HEX, OCTAL, INPUT, LFT, RHT, RPT, |
| | LTRIM, RTRIM, STS |
| | |
- -
| | |
| Functions returning integers: | ABS, LEN, MAX, MIN, ORD, POS, TYPEOF |
| | |
- -
| | |
| Other functions: | FINFO, SETVAR |
| | |
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The allowed operands are any variable, integer, string, or Boolean
constants, and the MPE/iX reserved words are WARN, FATAL, SYSTEM, and OK.
Compound logical expressions can be formed using the AND, NOT, XOR, and
OR logical operators, and nested within parentheses.
The THEN keyword is optional. It may be used or omitted and has no
effect on the results.
Operation Notes
This command begins an IF block consisting of all the commands after the
IF command up to, but not including, the next ELSE. ELSEIF, or ENDIF
statement. The ELSE, ELSEIF, or ENDIF must have the same nesting level
as the IF statement. Another similar block can follow the ELSE
statement.
Nesting of the blocks is allowed to 30 levels so long as IF is used
alone. In a case where IF is used with WHILE the total nesting of IF and
WHILE blocks cannot exceed 30 levels. Each IF or WHILE block read by the
Command Interpreter increments the nesting count even if it resides
within a different UDC or COMMAND file.
The ENDIF statement ends the IF block. The logical expression is
evaluated and, if the expression evaluates to TRUE, the IF block is
executed; if FALSE, the ELSE or ELSEIF block (if one exists) is executed.
NOTE You may not write an IF construct in such a way that it physically
crosses from one user command (UDCs or command files) to another.
Use
This command may be issued from a job, session, program, or in BREAK.
Pressing Break has no effect unless expression contains the INPUT
evaluator function.
Example
The following job listing illustrates the use of an IF statement with
ELSE and ENDIF statements:
!CONTINUE
!PASXL MYPROG,MYUSL
!IF JCW>=FATAL THEN
! TELL USER.TECHPUBS;COMPILE FAILED
!ELSE
! TELL USER.TECHPUBS;COMPILE COMPLETED
!ENDIF
Related Information
Commands CALC, ELSE, ELSEIF, ENDIF, WHILE, ENDWHILE, ESCAPE, RETURN
Manuals Appendix B, "Expression Evaluator Functions"