ENV

Derivation: ENVironment

ENV specifies the operating system for your C application. z/OS XL C++ users can get the same behavior by using the z/OS XL C++ compiler option TARGET(IMS) to specify ENV(IMS).

Restriction: This option does not apply to non-C languages and can be specified only with the C #pragma runopts directive. You cannot set this option at the system level, region level, or in the CEEBXITA assembler user exit interface.

For non-CICS applications, the ENV option differs from other runtime options that it does not have a standard default. The default depends on the system (CMS, IMS, or MVS) in which compilation occurs.

ENV is ignored under CICS®.

Read syntax diagramSkip visual syntax diagram ENV ( CMSIMSMVS )
CMS
Specifies that the C application runs in a CMS environment.
IMS
Specifies that the C application runs in an IMS environment. You do not need to specify the ENV option if your application is invoked under IMS but does not actually use IMS facilities.
MVS
Specifies that the C application runs in an MVS environment.

z/OS® UNIX considerations

  • In a multithreaded environment, the ENV option is shared by all threads in the process.