Establishing installation defaults

Note: This procedure involves making changes to an MVS™ component and modifying an authorized library. It can only be performed by your system programmer, who can provide you with a list of the defaults that have been established for your installation.

Default values for binder options can be customized to the needs of your installation by replacing a data-only load module in SYS1.LINKLIB. CSECT IEWBODEF in load module IEWBLINK can be used to specify default values for one or more options. The module is initially set to the null string but can be modified and configured to contain binder option default settings in the same form they would be specified in the JCL PARM field, without enclosing apostrophes or parentheses. A halfword length field preceding the string must be set to the current length of the string.

The following example shows how you can set the defaults for binder options FETCHOPT, LET and MSGLEVEL:

   IEWBODEF  CSECT
             DC     AL2(ENDPARM-PARMS)
   PARMS     EQU    *
             DC     C'COMPRESS=YES,'
             DC     C'FETCHOPT(NOPACK,NOPRIME),'
             DC     C'LET(4),'
             DC     C'MSGLEVEL(4)'
   ENDPARM   EQU    *
             END

Any options that can be set in the JCL PARM field can be defaulted in this manner. Notice the setting of the length and the comma delimiters between options. Once this module has been assembled it must be linked into module IEWBLINK, using either the linkage editor or binder, replacing the empty module.

It is recommended that only binder processing options, (for example, COMPAT, LINECT, LIST, MAP, and MSGLEVEL), be established for your installation. Module attributes, such as RMODE, REUS and OVLY, tend to vary from module to module, and changing the defaults for these attributes can result in unwanted conflicts. Note that utilities, such as IEBCOPY, invoke the binder to perform part of their processing, and any defaults established with this procedure can affect those utilities as well.

Installations planning to migrate from PDS load modules to PDSE or UNIX program objects may want to consider an installation default of COMPRESS=YES. This might result in as much as a 20 percent to 25 percent reduction in DASD space requirements for programs. However, program objects bound with COMPRESS=YES cannot be rebound or inspected (by AMBLIST or debuggers, for example) on any system older than z/OS® version 1 release 7.

The installation default can be overridden for calls to the binder, including those through the c89 and ld UNIX commands, TSO LINK, and the binder Application Programming Interface.

Note: The installation default also applies in some cases to IEBCOPY and the UNIX cp command. You cannot override the default for those programs.