The i/OS has an interesting and somewhat troublesome capability to allow us to change production objects on the fly during production up-time. While this capability provides us with the capability to maintain an up-time of 24x7, replacing production programs and other production objects during uptime allows us to have multiple versions of a production program running simultaneously, which can certainly cause problems. Nevertheless, the capability exists and we use it.

When creating a program, the compiler commands allow you to specify a REPLACE parameter as in the following:

CRTCLPGM PGM(PAYLIB/PAY001P) REPLACE(*YES)

Here, if the PAY001P program already exists, it will be replaced by the new version. The old version of the program is renamed, and moved to the library QRPLOBJ. Those users currently using the replaced program, will continue to use the old version(in QRPLOBJ), until they exit from that program and release the resolved program pointer or log off.

In addition to the standard options that are shown at the top of each PDM 'Work with' display, you can create your own user-defined PDM options. These user-defined options let you customize your PDM environment so you can be more productive.

Here are a few of the things you might do with user-defined options:

There are many occasions in which you need to locate a text string in a file, or, more often, in a series of source code members. Those of us that continue to use PDM(Program Development Manager) as a valuable tool in our toolbox can use PDM option 25(Find String) from the WRKMBRPDM and WRKOBJPDM displays. Entering this option causes PDM to search for any occurrence of the character string specified and perform an action, such as displaying the member containing the string, and/or printing a list of all members in which the string was found.

Because option 25 (Find string) is only available within the PDM environment, IBM created a special CL command that you can use to perform text searches when you are outside the PDM list environment. The command is named FNDSTRPDM (Find String using PDM), and it is shipped as part of the IBM Application Development Toolset LPP. You can use the FNDSTRPDM command interactively, or in batch, and you can include it in your programs. A wide variety of command options are available, making this command very flexible and quite powerful.

For our Unix readers, FNDSTRPDM is like the grep command on steroids.

In this article we'll examine the FNDSTRPDM command in detail and show examples for your productivity.