Routines (alphabetical) > Routines: E > EOF

# EOF

The EOF function tests the specified file unit for the end-of-file condition.

Note: The EOF function cannot be used with files opened with the RAWIO keyword to the OPEN routines. Many of the devices commonly used with RAWIO signal their end-of-file by returning a zero transfer count to the I/O operation that encounters the end-of-file.

## Examples

If file unit number 1 is open, the end-of-file condition can be checked by examining the value of the expression EOF(1). For example, the following IDL code reads and prints a text file:

; Open the file readme.txt:

OPENR, 1, 'readme.txt'

; Define a string variable:

A = ''

; Loop until EOF is found:

WHILE ~ EOF(1) DO BEGIN

; Read a line of text:

READF, 1, A

; Print the line:

PRINT, A

ENDWHILE

; Close the file:

CLOSE, 1

## Syntax

Result = EOF(Unit)

## Return Value

If the file pointer is positioned at the end of the file, EOF returns true (1), otherwise false (0) is returned.

## Arguments

### Unit

The file unit to test for end-of-file.

## Keywords

None.

## Version History

Original | Introduced

## See Also

POINT_LUN