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 associates 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