isatty (BPX2ITY, BPX4ITY) (X/Open Version) — Determine whether a file descriptor represents a terminal

Function

The isatty callable service determines whether a file is a terminal.

Requirements

Operation	Environment
Authorization:	Supervisor state or problem state, any PSW key
Dispatchable unit mode:	Task
Cross memory mode:	PASN = HASN
AMODE (BPX2ITY):	31-bit
AMODE (BPX4ITY):	64-bit
ASC mode:	Primary mode
Interrupt status:	Enabled for interrupts
Locks:	Unlocked
Control parameters:	All parameters must be addressable by the caller and in the primary address space.

Format

CALL BPX2ITY,(File_descriptor,
              Return_value,
              Return_code,
              Reason_code)

AMODE 64 callers use BPX4ITY with the same parameter.

Parameters

File_descriptor

Supplied parameter

Type:: Integer
Length:: Fullword

The name of a fullword that contains the file descriptor.

Return_value

Returned parameter

Type:: Integer
Length:: Fullword

The name of a fullword in which the isatty service returns 1 if File_descriptor is a terminal, or 0 if it is not a terminal.

Return_code

Returned parameter

Type:: Integer
Length:: Fullword

The name of a fullword in which the isatty service stores the return code. The isatty service may return Return_code only if Return_value is 0. See z/OS UNIX System Services Messages and Codes for a complete list of possible return code values. The isatty service can return one of the following values in the Return_code parameter:

Return_code	Explanation
EBADF	The filedes argument is not a valid open file descriptor.
ENOTTY	The filedes argument is not associated with a terminal.

Reason_code

Returned parameter

Type:: Integer
Length:: Fullword

The name of a fullword in which the isatty service stores the reason code. The isatty service may return Reason_code only if Return_value is 0. Reason_code further qualifies the Return_code value. For the reason codes, see z/OS UNIX System Services Messages and Codes.

Usage notes

This version of isatty is XPG4 compliant.
This function does not return -1. If the file descriptor is not valid, a zero is returned.

isatty (BPX2ITY, BPX4ITY) (X/Open Version) — Determine whether a file descriptor represents a terminal

Function

Requirements

Format

Parameters

Usage notes

Related services

Characteristics and restrictions

Examples