GNU.WIKI: The GNU/Linux Knowledge Base

  [HOME] [PHP Manual] [HowTo] [ABS] [MAN1] [MAN2] [MAN3] [MAN4] [MAN5] [MAN6] [MAN7] [MAN8] [MAN9]

  [0-9] [Aa] [Bb] [Cc] [Dd] [Ee] [Ff] [Gg] [Hh] [Ii] [Jj] [Kk] [Ll] [Mm] [Nn] [Oo] [Pp] [Qq] [Rr] [Ss] [Tt] [Uu] [Vv] [Ww] [Xx] [Yy] [Zz]


     VOP_READ, VOP_WRITE — read or write a file


     #include <sys/param.h>
     #include <sys/vnode.h>
     #include <sys/uio.h>

     VOP_READ(struct vnode *vp, struct uio *uio, int ioflag,
         struct ucred *cred);

     VOP_WRITE(struct vnode *vp, struct uio *uio, int ioflag,
         struct ucred *cred);


     These entry points read or write the contents of a file

     The arguments are:

     vp      The vnode of the file.

     uio     The location of the data to be read or written.

     ioflag  Various flags.

     cnp     The credentials of the caller.

     The ioflag argument is used to give directives and hints to the file
     system.  When attempting a read, the high 16 bits are used to provide a
     read-ahead hint (in units of file system blocks) that the file system
     should attempt.  The low 16 bits are a bit mask which can contain the
     following flags:

     IO_UNIT        Do I/O as atomic unit.

     IO_APPEND      Append write to end.

     IO_SYNC        Do I/O synchronously.

     IO_NODELOCKED  Underlying node already locked.

     IO_NDELAY      FNDELAY flag set in file table.

     IO_VMIO        Data already in VMIO space.


     The file should be locked on entry and will still be locked on exit.


     Zero is returned on success, otherwise an error code is returned.


     [EFBIG]            An attempt was made to write a file that exceeds the
                        process's file size limit or the maximum file size.

     [ENOSPC]           The file system is full.

     [EPERM]            An append-only flag is set on the file, but the caller
                        is attempting to write before the current end of file.


     uiomove(9), vnode(9)


     This manual page was written by Doug Rabson.

  All copyrights belong to their respective owners. Other content (c) 2014-2018, GNU.WIKI. Please report site errors to
Page load time: 0.118 seconds. Last modified: November 04 2018 12:49:43.