RFIO_OPEN(3)						      Rfio Library Functions						      RFIO_OPEN(3)

NAME

       rfio_open - opens a file

SYNOPSIS

       #include <sys/types.h>
       #include "rfio_api.h"

       int rfio_open (const char *path, int flags, int mode);

       Under Linux, for large files:
       #define _LARGEFILE64_SOURCE
       #include <sys/types.h>
       #include "rfio_api.h"

       int rfio_open64 (const char *path, int flags, int mode);

       For large files, under other systems:
       #include <sys/types.h>
       #include "rfio_api.h"

       int rfio_open64 (const char *path, int flags, int mode);

DESCRIPTION

       rfio_open  opens  the file whose name is the string pointed to by path, a character string containing the filename specification, and asso-
       ciates a FILE stream with it.
       flags are formed by ORing the following values:

	       O_RDONLY        Open for reading only
	       O_WRONLY        Open for writing only
	       O_RDWR	       Open for reading and writing
	       O_NDELAY        Do not block on open
	       O_APPEND        Append on each write
	       O_CREAT	       Create file if it does not exist
	       O_TRUNC	       Truncate size to 0
	       O_EXCL	       Error if create and file exists
	       O_LARGEFILE     When size can be superior to 2GB-1.
			       See NOTES

       mode specifies the permission bits to be set if the file is created.

       Opening a file with O_APPEND set causes each write on the file to be appended to the end.  If O_TRUNC is specified and the file exists, the
       file  is truncated to zero length.  If O_EXCL is set with O_CREAT, then if the file already exists, the open returns an error.  This can be
       used to implement a simple exclusive access locking mechanism.  If O_EXCL is set and the last component of the pathname is a symbolic link,
       the  open  will	succeed  even  if the symbolic link points to an existing name.  If the O_NDELAY flag is specified and the open call would
       result in the process being blocked for some reason (for example waiting for a carrier on a dial-up line), the  open  returns  immediately.
       The  first time the process attempts to perform IO on the open file, it will block (not currently implemented). On systems that support the
       Large Files, O_LARGEFILE in rfio_open allows files whose sizes cannot be represented in 31 bits to be opened.

RETURN VALUE

       If successful, returns a non-negative integer which may be used to refer to the file on subsequent  rfio_write,	rfio_read  and	rfio_close
       calls.  On failure, rfio_open returns -1 and the error code is stored in serrno.

ERRORS

       ENOENT	    The named file/directory does not exist or is a null pathname.

       EACCES	    Search permission is denied on a component of the path prefix.

       EBUSY	    Device or resource busy. Happens if you try to open in write mode a LCG file that is in an active migration stream.

       EFAULT	    path is a NULL pointer.

       ENOTDIR	    A component of path prefix is not a directory.

       ENAMETOOLONG The length of path exceeds CA_MAXPATHLEN or the length of a path component exceeds CA_MAXNAMELEN.

       SENOSHOST    Host unknown.

       SENOSSERV    Service unknown.

       SECOMERR     Communication error.

SEE ALSO

       Castor_limits(4),rfio_write(3),rfio_read(3),rfio_close(3)

NOTES

       On  Irix,  Tru64  and  IA64 the 64 bit mode is the default one, open and open64 are identical. The flag O_LARGEFILE is accepted on Irix and
       IA64 (where it has no effect) but not on Tru64.	On all other platforms, rfio_open with O_LARGEFILE is equivalent to a call to rfio_open64.

AUTHOR

       LCG Grid Deployment Team

LCG
							   $Date: 2005/03/31 13:13:03 $ 					      RFIO_OPEN(3)