# NAG FL Interfacex04adf (close)

## ▸▿ Contents

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## 1Purpose

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

## 2Specification

Fortran Interface
 Integer, Intent (In) :: iounit Integer, Intent (Inout) :: ifail
#include <nag.h>
 void x04adf_ (const Integer *iounit, Integer *ifail)
The routine may be called by the names x04adf or nagf_file_close.

## 3Description

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

None.

## 5Arguments

1: $\mathbf{iounit}$Integer Input
On entry: the Fortran unit number which identifies the file to be closed.
2: $\mathbf{ifail}$Integer Input/Output
On entry: ifail must be set to $0$, $-1$ or $1$ to set behaviour on detection of an error; these values have no effect when no error is detected.
A value of $0$ causes the printing of an error message and program execution will be halted; otherwise program execution continues. A value of $-1$ means that an error message is printed while a value of $1$ means that it is not.
If halting is not appropriate, the value $-1$ or $1$ is recommended. If message printing is undesirable, then the value $1$ is recommended. Otherwise, the value $0$ is recommended. When the value $-\mathbf{1}$ or $\mathbf{1}$ is used it is essential to test the value of ifail on exit.
On exit: ${\mathbf{ifail}}={\mathbf{0}}$ unless the routine detects an error or a warning has been flagged (see Section 6).

## 6Error Indicators and Warnings

If on entry ${\mathbf{ifail}}=0$ or $-1$, explanatory error messages are output on the current error message unit (as defined by x04aaf).
Errors or warnings detected by the routine:
${\mathbf{ifail}}=1$
Cannot close file associated with channel $⟨\mathit{\text{value}}⟩$.
${\mathbf{ifail}}=-99$
An unexpected error has been triggered by this routine. Please contact NAG.
See Section 7 in the Introduction to the NAG Library FL Interface for further information.
${\mathbf{ifail}}=-399$
Your licence key may have expired or may not have been installed correctly.
See Section 8 in the Introduction to the NAG Library FL Interface for further information.
${\mathbf{ifail}}=-999$
Dynamic memory allocation failed.
See Section 9 in the Introduction to the NAG Library FL Interface for further information.

Not applicable.

## 8Parallelism and Performance

x04adf is not threaded in any implementation.

None.

## 10Example

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.