PickBASIC / FlashBASIC

%open() function

The %open() function opens the host OS file specified by str and sets the file status flags according to the value of oflag.

Syntax

 file.descriptor = %open(str, oflag, pmode)

Parameter(s)


`str`	Specifies the file name to open or create.
`oflag`	Specifies the status of the file. Valid values are defined in the include file: fcntl.h. Multiple flags can be specified in the syntax.
	`O$APPEND`	Moves the file pointer to the end of the file.
	`O$BINARY`	Opens in binary mode.
	`O$CREAT`	Creates a new file with the name specified in `str`. Owner-ID and group-ID are set. The mode of the file is set according to the value of `mode` modified as follows: all bits in the file mode creation mask of the process are cleared and the sticky bit is cleared. If no value for the mode is specified when using the O$CREAT flag, an arbitrary value is used from your stack and undefined permissions are used.
	`O$EXCL`	If O$EXCL and O$CREAT are set, open fails if the file exists.
	`O$NDELAY`	Nonblocking I/O. The effect of this flag varies depending on the type of the file. See host OS system documentation.
	`O$RDONLY`	Opens for reading only.
	`O$RDWR`	Opens for reading and writing.
	`O$SYNC`	Synchronized writes.
	`O$TEXT`	Opens in text mode and translates text (default). For example: `^Z` is assumed to be an end of line.
	`O$TRUNC`	If the file exists, its length is set to 0.
	`O$WRONLY`	Opens for writing only.
`pmode`	Specifies the read-write permissions for newly created files opened with the O$CREAT flag. Valid values are defined in the include file: mode.h. If no value for the mode is specified when using the O$CREAT flag, an arbitrary value is used from your stack and undefined permissions are used.
	`S$IRUSR`	UNIX only. Opens a new file with read only permissions.
	`S$IWUSR`	UNIX only. Opens a new file with write only permissions.
	`S$IREAD`	Windows only. Opens a new file with read only permissions.
	`S$IWRITE`	Windows only. Opens a new file with write only permissions.

Description

Files opened by %open() are closed automatically when the FlashBASIC program terminates.

The file descriptor is returned as a number or -1 if an error occurred. system(0) contains the error number.

Note:

There is a limit on the number of host OS files a process can have opened simultaneously. See your platform documentation.
Files opened by a FlashBASIC program are normally closed automatically when the program terminates. However, it is a good practice to close them.

Example(s)

include dm,bp,unix.h fcntl.h
fd=%open(’fname’, o$wronly+o$append)
if fd<0 then
   crt ’Cannot open. errno=’:system(0)
end

See also

%close() function→%filecheck() function→%fsize() function→%lseek() function→%rdhex() function→%read() function→%ttyname() function→%unlink ()function→%whex() function→%write() function→FlashBASIC C functions overview→cfunction statement→