_o_AP fopen

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4D Pack v15.1

_o_AP fopen


_o_AP fopen ( toOpen ; mode ) -> Function result

Parameter	Type	Description
toOpen	String	Name of the file or port to be opened
mode	Integer	Opening mode 0 = write only 1 = read only
Function result	Longint	Value to be used with AP FPRINT, or 0 if the file or port cannot be open

Description

The _o_AP fopen command calls the fopen ANSI C command, which enables the opening of serial or parallel ports (on Windows) or the direct creation of files.

The value returned by this function is then used with the _o_AP FPRINT command to write through the port, or to write the file. The opened port or file can then be closed using the command _o_AP FCLOSE.

Note: On Mac OS, this function works only with the direct creation of files.

Example 1

Writing "hello world" on the parallel port:

 port:=_o_AP fopen("LPT1";0)

 _o_AP FPRINT(port;"hello world")

 _o_AP FCLOSE(port)

Example 2

Writing "hello world" on the serial port:

 port:=_o_AP fopen("COM1";0)

 _o_AP FPRINT(port;"hello world")

 _o_AP FCLOSE(port)

Example 3

Writing "hello world" in a file:

 port:=_o_AP fopen("C:\MyDoc.txt";0)

 _o_AP FPRINT(port;"hello world")

 _o_AP FCLOSE(port)

Example 4

Reading a file:

 port:=_o_AP fopen("C:\MyDoc.txt";1)

 MyVar:=_o_AP fread(port)

 _o_AP FCLOSE(port)