umask (BPX1UMK, BPX4UMK) — Set the file mode creation mask

Function

The umask callable service changes the file mode creation mask of a process. The file mode creation mask is used by the security package to turn off permission bits in the mode parameter that is specified. Bit positions that are set in the file mode creation mask are cleared in the mode of the created file.

Requirements

Parameters

File_mode_creation_mask

Supplied parameter

Type:

Structure

Length:

Fullword

The name of a fullword that contains the file mode creation mask. This mask turns off permission bits in a file's mode. File_mode_creation_mask is mapped by the BPXYMODE macro (see BPXYMODE — Map the mode constants of the file services).

Return_value

Returned parameter

Type:

Integer

Length:

Fullword

The name of a fullword in which the umask service returns the previous value of the file mode creation mask. This fullword has the same mapping as the File_mode_creation_mask parameter.

Usage notes

1. The umask service changes the process's file creation mask. This mask controls file permission bits that are set whenever the process creates a file. File permission bits that are turned on in the file creation mask are turned off in the file permission bits of files that are created by the process. For example, if a call to the open (BPX1OPN, BPX4OPN) service specifies a "mode" argument with file permission bits, the process's file creation mask affects that argument: Bits that are on in the mask are turned off in the "mode" argument, and therefore in the mode of the created file.
2. Only the file permission bits of the new mask are used. For example, the type of file field in File_Mode cannot be masked.

Related services

• mkdir (BPX1MKD, BPX4MKD) — Make a directory
• open (BPX1OPN, BPX4OPN) — Open a file

Characteristics and restrictions

There are no restrictions on the use of the umask service.