osf1 man page for fdatasync

fdatasync(2)							System Calls Manual						      fdatasync(2)

NAME
       fdatasync -  Writes data changes in a file to permanent storage

SYNOPSIS
       #include <unistd.h>

       int fdatasync (	    int fildes );

PARAMETERS
       Specifies a valid open file descriptor.

DESCRIPTION
       The  fdatasync function causes system buffers containing a file's modified data to be written to permanent storage.  The fdatasync function
       does not return until the operation has been completed. The fdatasync function provides data integrity, ensuring  that  data  in  permanent
       storage	is  identical  to data in the buffer. However, use of fdatasync does not guarantee that file control information such as owner and
       modification time has been updated to permanent storage (see the fsync function).

NOTES
       The file identified by the fildes parameter must be open for writing when the fdatasync function is issued or the call will fail.

RETURN VALUES
       Upon successful completion, the fdatasync function returns a value of 0 (zero). If the fdatasync function fails, a value of -1 is  returned
       and errno is set to indicate the error. If fdatasync fails, outstanding I/O operations are not guaranteed to have been completed.

ERRORS
       If the fdatasync function fails, errno may be set to one of the following values:

       [EBADF]	      The fildes parameter is not a valid file descriptor.

       [EINVAL]       The fildes parameter does not refer to a file on which this operation is possible.

       If any queued I/O operations fail, the fdatasync function returns error conditions defined for the read and write functions.

RELATED INFORMATION
       Functions: fcntl(2), fsync(2), open(2), read(2), sync(2), write(2) delim off

																      fdatasync(2)