Parallel Engineering and Scientific Subroutine Library for AIX Version 2 Release 3: Guide and Reference

IPESSL--Determine the Level of Parallel ESSL Installed on Your System

This function returns the current level of Parallel ESSL installed on your system, where the level consists of a version number, release number, and modification number, plus the fix number of the most recent PTF installed.

Note:

This subroutine is useful to you in those instances where your program is using a subroutine or feature that exists only in certain levels of Parallel ESSL. It is also useful when your program is dependent upon certain PTFs being applied to Parallel ESSL.

Syntax

On Return

Function value

is the level of Parallel ESSL installed on your system. It is provided as a fullword integer in the form vvrrmmff, where each two digits represents a part of the level:

• vv is the version number.
• rr is the release number.
• mm is the modification number.
• ff is the fix number of the most recent PTF installed.

Scope: global

Returned as: a fullword integer; vvrrmmff > 0.

Notes

1. To use IPESSL effectively, you must install your Parallel ESSL PTFs in their proper sequential order. As part of the result, IPESSL returns the value ff of the most recent PTF installed, rather than the highest number PTF installed. Therefore, if you do not install your PTFs sequentially, the ff value returned by IPESSL does not reflect the actual level of ESSL.
2. Declare the IPESSL function in your program as returning a fullword integer value.
3. For the first release of Parallel ESSL for AIX Version 4, vv = 01 and rr = 01, and IPESSL returns 1010000.

Example

This example shows several ways to use the IPESSL function. Most typically, you use IPESSL for checking the version and release level of Parallel ESSL. Suppose you are dependent on a new capability in Parallel ESSL, such as a new subroutine or feature, provided for the first time in (fictitious) Parallel ESSL Version 3 Release 2. You can add the following check in your program before using the new capability:

   IF IPESSL() >= 3020000

By specifying 0000 for mmff, the modification and fix level, you are independent of the order in which your modifications and PTFs are installed.

Less typically, you use IPESSL for checking the PTF level of Parallel ESSL. Suppose you are dependent on (fictitious) PTF 24 being installed on your Parallel ESSL Version 1 Release 0 system You want to know whether to call a different user-callable subroutine to set up your array data. You can add the following check in your program before making the call:

   IF IPESSL() >= 1000024

If your system support group installed the Parallel ESSL PTFs in their proper sequential order, this test works properly; otherwise, it is unpredictable.