X04ABF (PDF version)
X04 Chapter Contents
X04 Chapter Introduction
NAG Library Manual

NAG Library Routine Document

X04ABF

Note:  before using this routine, please read the Users' Note for your implementation to check the interpretation of bold italicised terms and other implementation-dependent details.

+ Contents

    1  Purpose
    7  Accuracy

1  Purpose

X04ABF returns the value of the current advisory message unit number, or sets the current advisory message unit number to a new value.

2  Specification

SUBROUTINE X04ABF ( IFLAG, NADV)
INTEGER  IFLAG, NADV

3  Description

X04ABF enables those library routines which output advisory messages to determine the number of the output unit to which the advisory messages are to be sent; in this case X04ABF is called with IFLAG=0. X04ABF may also be called with IFLAG=1 to set the unit number to a specified value. Otherwise a default value (stated in the Users' Note for your implementation) is returned.
Records written to this output unit by other library routines are at most 120 characters long (including a line-printer carriage control character), unless those library routines allow you to specify longer records.
Note that if the unit number is set <0, no messages will be output.

4  References

None.

5  Parameters

1:     IFLAG – INTEGERInput
On entry: the action to be taken (see NADV).
Constraint: IFLAG=0 or 1.
2:     NADV – INTEGERInput/Output
On entry: if IFLAG=0, NADV need not be set.
If IFLAG=1, NADV must specify the new advisory message unit number.
On exit: if IFLAG=0, NADV is set to the current advisory message unit number.
If IFLAG=1, NADV is unchanged.
Note that Fortran unit numbers must be positive or zero. If NADV is set <0, output of advisory messages is totally suppressed.

6  Error Indicators and Warnings

None.

7  Accuracy

Not applicable.

8  Further Comments

The time taken by X04ABF is negligible.

9  Example

In this example X04ABF is called by your main program to make the advisory message from the routine DUMMY appear on the same unit as the rest of the output (unit 6). Normally a NAG Library routine with an IFAIL parameter (see Section 3.3.2 in the Essential Introduction) would take the place of DUMMY.

9.1  Program Text

Program Text (x04abfe.f90)

9.2  Program Data

None.

9.3  Program Results

Program Results (x04abfe.r)


X04ABF (PDF version)
X04 Chapter Contents
X04 Chapter Introduction
NAG Library Manual

© The Numerical Algorithms Group Ltd, Oxford, UK. 2012