EOF - test input end-of-file, or write output end-of-file.

Alternate Entry Name: .EOF

Usage:

B:
   stat = eof( [unit] );

/* C users should use "feof" */

Where:

unit

is the number of the I/O unit to be tested or ended. If "unit" is not specified, the current read unit is tested for end-of-file.

stat

When testing an input unit, "stat" receives an end-of-file indicator if the unit is at end-of-file. If the file was opened with the "zc" option for OPEN, EOF is indicated by a "stat" of -1; otherwise, it is indicated by a "stat" of 0. In the C library, the "zc" option is the default. When writing on an output unit, "stat" always receives a non-zero value.

Description:

If EOF is called for an input unit, the function tests whether or not the unit is in end-of-file status. If EOF is called for an output unit, the function writes an end-of-file on the unit. When EOF is called to handle an output unit which is a disk file, an end-of-file mark is written and a new block begun.

Note that using EOF on output units is only for very special applications. Normally you would accomplish the same result by closing the unit and reopening it with no rewind.

Note that an input unit is placed in end-of-file status only after a read results in an end-of-file being detected.

See Also:

expl c lib feof

the ANSI C function to check for end-of-file. Note that "feof" only works on input units and returns a different value to indicate end-of-file.

Copyright © 1996, Thinkage Ltd.