Topic       : The GFA-Basic Compendium
Author      : GFA Systemtechnik GmbH
Version     : GFABasic.HYP v2.98 (12/31/2023)
Subject     : Documentation/Programming
Nodes       : 899
Index Size  : 28056
HCP-Version : 3
Compiled on : Atari
@charset    : atarist
@lang       : 
@default    : Document not found
@help       : Help
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@width      : 75
@hostname   : STRNGSRV
@hostname   : CAB     
@hostname   : HIGHWIRE
@hostname   : THING   
View Ref-FileLOF(#n)
LOC(#n)
EOF(#n)
CLOSE [#n]
TOUCH [#]n

n: iexp

The numerical expression n refers to the channel number previously specified
with OPEN.

LOF() (length of file) returns the length of a file in bytes.

LOC() (location) returns the current position of the data pointer measured in
bytes from the beginning of the file. (where LOC() returns zero). See also
SEEK.

EOF() (end of file) determines whether the data pointer points to the end of a
file (or the whole file has been read). If the data pointer does point to the
end of the file, TRUE (-1) is returned, otherwise FALSE (0).

CLOSE closes a data channel to a file or peripheral device previously opened
with OPEN. The numerical expression n contains the number of the channel to be
closed. If the channel number is omitted, all open files are closed.

TOUCH updates the date and time stamps of a file, giving it the current system
date and time.

Examples:

    OPEN "o",#1,"TEST.TXT"
    FOR i%=1 to 20
      PRINT #1,STR$(i%)
    NEXT i%
    CLOSE #1
    FILES "TEST.TXT"
    DELAY 20               ! Wait 20 seconds
    OPEN "u",#1,"TEST.TXT"
    TOUCH #1
    CLOSE #1
    FILES "TEST.TXT"

--> In the example the file TEST.TXT is opened, written to, and closed. Then
    the file information is displayed, including the time and date. Twenty
    seconds later the file is opened again, the date and time updated, then
    closed. The file information is displayed again.

    OPEN "i",#1,"TEST.TXT"
    PRINT "file length: ";LOF(#1)
    PRINT
    PRINT "data","position of the data pointer"
    DO UNTIL EOF(#1)
      INPUT #1,a$
      PRINT "";a$,LOC(#1)
    LOOP
    CLOSE #1

--> The example opens the file from the previous example for reading.  First
    the length of the file is displayed by means of LOF(). Then the contents of
    the file are displayed along with the associated data pointer position
    until the termination condition of the loop is met when EOF() is TRUE.

Memo: TOUCH does not issue an error if the #channel is wrong.
      TOUCH doesn't work in the editor or compiled, just does nothing.
      CLOSE #n does not issue an error if the #channel is wrong.
      EOF(), LOC(), and LOF() don't issue errors if the #channel is wrong.

      Note: EOF() often fails on emulators using the HostFS!
            Failures have been seen with ARAnyM and Hatari.
            Solution: Use a disk image.

Fclose()+, Fdatime()+