4D Doc Center : AP fopen

4D Pack v13.2

AP fopen


AP fopen ( ; mode ) -> Function result

Parameter	Type	Description
	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 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 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 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:=AP fopen("LPT1";0)

 AP FPRINT(port;"hello world")

 AP FCLOSE(port)

Example 2

Writing "hello world" on the serial port:

 port:=AP fopen("COM1";0)

 AP FPRINT(port;"hello world")

 AP FCLOSE(port)

Example 3

Writing "hello world" in a file:

 port:=AP fopen("C:\myfile.txt";0)

 AP FPRINT(port;"hello world")

 AP FCLOSE(port)

Example 4

Reading a file:

 port:=AP fopen("C:\myfile.txt";1)

 MyVar:=AP fread(port)

 AP FCLOSE(port)