Topic       : The GFA-Basic Compendium
Author      : GFA Systemtechnik GmbH
Version     : GFABasic.HYP v2.98 (12/31/2023)
Subject     : Documentation/Programming
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Index Size  : 28056
HCP-Version : 3
Compiled on : Atari
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View Ref-FileINP(#n)
INP&(#n)
INP%(#n)
OUT #n,a[,b,c,...]
OUT& #n,a[,b,c,...]
OUT% #n,a[,b,c,...]

n: iexp

INP(#n) reads a byte from a file which has been previously opened with OPEN.
The numerical expression n is the channel number under which the file was
OPENed.

INP&(#n) reads a word (two-byte value) from a file.

INP%(#n) reads a long (four-byte value) from a file. Thus a%=INP%(#1) can
replace a%=CVL(INPUT$(4,#1)).

OUT #n sends a byte to a file which was been previously opened with OPEN. The
numerical expression n is the channel number under which the file was OPENed.
Only the low-order 8 bits of a, b, c, ... are output, thus limiting their
values to 255.

OUT& #n sends a word (two-byte value) to a file.

OUT% #n sends a long (four-byte value) to a file.

INP() and OUT without the '#' can also be used for communication with the
screen, keyboard, etc. (e.g. INP(2) reads a character from the keyboard). See
the section called "Communicating with Peripherals".

Example:

    OPEN "o",#1,"TEST.TXT"
    OUT #1,128
    CLOSE #1
    '
    OPEN "i",#1,"TEST.TXT"
    a=INP(#1)
    CLOSE #1
    PRINT a

--> In the first part of the example a file is opened for output and a byte is
    written to it. In the second part this byte is read back in as the variable
    'a' which when printed is revealed to have the value 128.

Memo: INP(#n), INP&(#n), and INP%(#n) incorrectly return error code 0 if
      the #channel number is incorrect.

Fread()+, Fwrite()+