PXFOPEN

POSIX Subroutine: Opens or creates a file.

Module

USE IFPOSIX

CALL PXFOPEN (path,ilen,iopenflag,imode,ifildes,ierror)

path	(Input) Character. The path of the file to be opened or created.
ilen	(Input) INTEGER(4). The length of path string.
iopenflag	(Input) INTEGER(4). The flags for the file. (For possible constant names that can be passed to PXFCONST or IPXFCONST, see below.)
imode	(Input) INTEGER(4). The permissions for a new file. This argument should always be specified when iopenflag=O_CREAT; otherwise, it is ignored. (For possible permissions, see below.)
ifildes	(Output) INTEGER(4). The returned file descriptor for the opened or created file.
ierror	(Output) INTEGER(4). The error status.

If successful, ierror is set to zero; otherwise, an error code.

For iopenflag, you should specify one of the following constant values:

O_RDONLY (read only)
O_WRONLY (write only)
O_RDWR (read and write)

In addition, you can also specify one of the following constant values by using a bitwise inclusive OR (IOR):

Value	Action
O_CREAT	Creates a file if the file does not exist.
O_EXCL	When used with O_CREAT, it causes the open to fail if the file already exists. In this case, a symbolic link exists, regardless of where it points to.
O_NOCTTY¹	If `path` refers to a terminal device, it prevents it from becoming the process's controlling terminal even if the process does not have one.
O_TRUNC	If the file already exists, it is a regular file, and `imode` allows writing (its value is O_RDWR or O_WRONLY), it causes the file to be truncated to length 0.
O_APPEND	Opens the file in append mode. Before each write, the file pointer is positioned at the end of the file, as if with PXFLSEEK.
O_NONBLOCK (or O_NDELAY)¹	When possible, opens the file in non-blocking mode. Neither the open nor any subsequent operations on the file descriptor that is returned will cause the calling process to wait. This mode need not have any effect on files other than FIFOs.
O_SYNC	Opens the file for synchronous I/O. Any writes on the resulting file descriptor will block the calling process until the data has been physically written to the underlying hardware.
O_NOFOLLOW¹	If `path` is a symbolic link, it causes the open to fail.
O_DIRECTORY¹	If `path` is not a directory, it causes the open to fail.
O_LARGEFILE¹	On 32-bit systems that support the Large Files System, it allows files whose sizes cannot be represented in 31 bits to be opened.
O_BINARY²	Opens the file in binary (untranslated) mode.
O_SHORT_LIVED²	Creates the file as temporary. If possible, it does not flush to the disk.
O_TEMPORARY²	Creates the file as temporary. The file is deleted when last file handle is closed.
O_RANDOM²	Specifies primarily random access from the disk.
O_SEQUENTIAL²	Specifies primarily sequential access from the disk.
O_TEXT²	Opens the file in text (translated) mode. ³
¹LX only ²WS ²WS ³For more information, see "Text and Binary Modes" in the Visual C++ programmer's guide.

Argument imode specifies the permissions to use if a new file is created. The permissions only apply to future accesses of the newly created file. The value for imode can be any of the following constant values (which can be obtained by using PXFCONST or IPXFCONST):

Value	Description
S_IRWXU	00700 user (file owner) has read, write and execute permission.
S_IRUSR, S_IREAD	00400 user has read permission.
S_IWUSR, S_IWRITE	00200 user has write permission.
S_IXUSR, S_IEXEC	00100 user has execute permission.
S_IRWXG¹	00070 group has read, write and execute permission.
S_IRGRP¹	00040 group has read permission.
S_IWGRP¹	00020 group has write permission.
S_IXGRP¹	00010 group has execute permission.
S_IRWXO¹	00007 others have read, write and execute permission.
S_IROTH¹	00004 others have read permission.
S_IWOTH¹	00002 others have write permission.
S_IXOTH¹	00001 others have execute permission.
¹L*X only

Example

The following call opens a file for writing only and if the file does not exist, it is created:

call PXFOPEN( "OPEN.OUT", &
               8, &
               IOR( IPXFCONST(O_WRONLY), IPXFCONST(O_CREAT) ), &
               IOR( IPXFCONST(S_IREAD), IPXFCONST(S_IWRITE) ) )

PXFOPEN

Module

Example

See Also