NAG Library Routine Document

x04adf (close)

1
Purpose

x04adf closes a file associated with a given Fortran unit number.

2
Specification

Fortran Interface
Subroutine x04adf ( iounit, ifail)
Integer, Intent (In):: iounit
Integer, Intent (Inout):: ifail
C Header Interface
#include <nagmk26.h>
void  x04adf_ (const Integer *iounit, Integer *ifail)

3
Description

x04adf is especially useful if the calling language is not Fortran. It closes a file associated with a given Fortran unit number.

4
References

None.

5
Arguments

1:     iounit – IntegerInput
On entry: the Fortran unit number which identifies the file to be closed.
2:     ifail – IntegerInput/Output
On entry: ifail must be set to 0, -1 or 1. If you are unfamiliar with this argument you should refer to Section 3.4 in How to Use the NAG Library and its Documentation for details.
For environments where it might be inappropriate to halt program execution when an error is detected, the value -1 or 1 is recommended. If the output of error messages is undesirable, then the value 1 is recommended. Otherwise, if you are not familiar with this argument, the recommended value is 0. When the value -1 or 1 is used it is essential to test the value of ifail on exit.
On exit: ifail=0 unless the routine detects an error or a warning has been flagged (see Section 6).

6
Error Indicators and Warnings

If on entry ifail=0 or -1, explanatory error messages are output on the current error message unit (as defined by x04aaf).
Errors or warnings detected by the routine:
ifail=1
Cannot close file associated with channel value.
ifail=-99
An unexpected error has been triggered by this routine. Please contact NAG.
See Section 3.9 in How to Use the NAG Library and its Documentation for further information.
ifail=-399
Your licence key may have expired or may not have been installed correctly.
See Section 3.8 in How to Use the NAG Library and its Documentation for further information.
ifail=-999
Dynamic memory allocation failed.
See Section 3.7 in How to Use the NAG Library and its Documentation for further information.

7
Accuracy

Not applicable.

8
Parallelism and Performance

x04adf is not threaded in any implementation.

9
Further Comments

None.

10
Example

This example program simply illustrates how to close a file once it has been opened for writing followed by how to close a file once it has been opened for reading.

10.1
Program Text

Program Text (x04adfe.f90)

10.2
Program Data

None.

10.3
Program Results

Program Results (x04adfe.r)