Exit Program for Change Directory Entry Attributes (QHFCHGAT) API

Before applications can use the Change Directory Entry Attributes (QHFCHGAT) API with your file system, you must:

1. Write an exit program that performs the change attribute operation on behalf of the API. For a detailed description of the API and its calling parameters, see Change Directory Entry Attributes (QHFCHGAT) API.
   
   
2. Give the exit program's name when you register the file system with the Register File System API, QHFRGFS.

After that, when an application calls the QHFCHGAT API, the API calls your exit program and passes it the parameters specified by the application. Your exit program performs the work and returns any data to the API. The API passes the data back to the calling application.

Authorities and Locks

None.

Required Parameter Group

The API passes this information to your exit program:

Operation (CHGAT)

INPUT; CHAR(5)

The abbreviation for the operation being performed (CHGAT).

File system job handle

INPUT; CHAR(16)

The work area or job identifier for use by the file system.

Reserved

INPUT; CHAR(20)

Reserved for future use. This parameter is set to blanks.

Except as noted, the following parameters are the same as the parameters for the API.

Path name

INPUT; CHAR(*)

The API removes the file system name before passing the path name to the exit program.

Path name length

INPUT; BINARY(4)

Attribute information table

INPUT; CHAR(*)

Length of the attribute information table

INPUT; BINARY(4)

API Functions

The QHFCHGAT API performs the standard functions described in Standard HFS API Functions. The API does not validate the attribute information table in any way. It checks only the length parameter to make sure it has a valid value.

Exit Program Requirements

You must create an exit program that performs the standard functions described in Standard HFS Exit Program Requirements and these additional functions:

• Validates the attribute information table.
  
  
• Changes valid attributes in the directory entry.
  
  
• Ignores a request to delete an attribute that does not exist for the directory entry.
  
  
• Ignores a request to change an attribute that cannot be changed or that does not apply to the directory entry. For example, the exit program must ignore requests to change the QFILSIZE attribute in a directory entry for a directory object and must ignore requests to change directories to files, or vice versa.

Error Messages for Exit Program Use

This section lists the messages that the exit program can return to the API.