OPENDISK(3)               OpenBSD Programmer's Manual              OPENDISK(3)

NAME
     opendisk - open a disk's ``raw'' partition



LIBRARY
SYNOPSIS
     #include <util.h>

     int
     opendisk(const char *path, int flags, char *buf, size_t buflen,
             int iscooked);

DESCRIPTION
     opendisk() opens path, for reading and/or writing as specified by the ar-
     gument flags using open(2),  and the file descriptor is returned to the
     caller.  buf is used to store the resultant filename.  buflen is the
     size, in bytes, of the array referenced by buf (usually MAXPATHLEN
     bytes).  If iscooked is non zero, the ``cooked'' partition (block device)
     is opened, rather than the ``raw'' partition (character device).

     opendisk() attempts to open the following variations of path, in order:

     path         The pathname as given.

     pathX        path with a suffix of `X', where `X' represents the raw par-
                  tition of the device, as determined by getrawpartition(3),
                  usually ``c''.

     If iscooked is zero, then the following two variations are attempted:

     /dev/rpath   path with a prefix of ``/dev/r''.

     /dev/rpathX  path with a prefix of ``/dev/r'' and a suffix of `X' (q.v.).

     Otherwise (i.e., iscooked is non-zero), the following variations are at-
     tempted:

     /dev/path    path with a prefix of ``/dev/''.

     /dev/pathX   path with a prefix of ``/dev/'' and a suffix of `X' (q.v.).

RETURN VALUES
     An open file descriptor, or -1 if the open(2) failed.

ERRORS
     opendisk() may set errno to one of the following values:

     [EINVAL]      O_CREAT was set in flags, or getrawpartition(3) didn't re-
                   turn a valid partition.

     [EFAULT]      buf was the NULL pointer.

     The opendisk() function may also set errno to any value specified by the
     open(2) function.

SEE ALSO
     open(2),  getrawpartition(3)

HISTORY
     The opendisk() function first appeared in NetBSD 1.3.

OpenBSD 2.6                   September 22, 1997                             1