Dynamic invocation of the HZAZIP program by other programs

Other programs can call the HZAZIP utility to perform compression and decompression processing requests. When the HZAZIP utility receives control, it examines the program parameter list and proceeds accordingly.

The first program parameter must begin with a halfword counter indicating the length of the function request text that immediately follows. The format is the same format as the system uses to pass the parameter specified in the PARM operand of the EXEC statement in JCL.

A second program parameter can be specified to override the default file names used by the HZAZIP utility. If the value of the halfword length indicator at the start of the parameter is not a multiple of 8 or is not less than 256, the HZAZIP utility ignores it. A series of 8-byte file name entries immediately follow the length indicator and each can specify the DD name to use instead of the default name. Set a slot to 8 bytes of zeros to avoid overriding that particular default file name. SYSPRINT, SYSUT1 and SYSUT2 correspond to the sixth, eighth and ninth file name slots respectively.