Search order for DLLs in the z/OS UNIX file system
When you use the z/OS® UNIX file system,
the search order for resolving a DLL reference in a CALL
statement
depends on the setting of the Language Environment® POSIX
runtime
option.
If the POSIX
runtime option is ON
,
the search order is as follows:
- The runtime environment looks for the DLL in the z/OS UNIX file system. If the LIBPATH environment variable is set, the run time searches each directory listed. Otherwise, it searches just the current directory. The search for the DLL in the z/OS UNIX file system is case sensitive.
- If the runtime environment does not find the DLL in the z/OS UNIX file system, it tries to load the DLL from the MVS™ load library search order of the caller. In this case, the DLL name must be eight characters or less. The run time automatically converts the DLL name to uppercase for this search.
If the POSIX
runtime option is set to OFF
,
the search order is reversed:
- The runtime environment tries to load the DLL from the search order for the load library of the caller.
- If the runtime environment cannot load the DLL from this load library, it tries to load the DLL from the z/OS UNIX file system.
related references
Language Environment Programming Reference (POSIX)
Language Environment Programming Reference (POSIX)