NAME
opendisk —
open a disk partition
LIBRARY
library “libutil”
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 argument 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).
iscooked controls which paths in
/dev are tried.
opendisk()
attempts to open the following variations of path, in
order:
If path does not contain a slash (“/”), the following variations are attempted:
- If iscooked is zero:
- /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.).
- If iscooked is non-zero:
- /dev/path
- path with a prefix of “/dev/”.
- /dev/pathX
- path with a prefix of “/dev/” and a suffix of ‘X’ (q.v.).
If the above fails, then the original path is tried using the following two variations:
- The iscooked value is ignored:
- path
- The pathname as given.
- pathX
- path with a suffix of ‘X’, where ‘X’ represents the raw partition of the device, as determined by getrawpartition(3), usually “c”.
RETURN VALUES
An open file descriptor, or -1 if the open(2) failed.
ERRORS
opendisk() may set
errno to one of the following values:
- [
EFAULT] - buf was the
NULLpointer. - [
EINVAL] O_CREATwas set in flags, or getrawpartition(3) didn't return a valid partition.
The opendisk() function may also set
errno to any value specified by the
open(2) function.
SEE ALSO
HISTORY
The opendisk() function first appeared in
NetBSD 1.3.
The lookup order of opendisk() was changed
in NetBSD 7.1 to first look in
/dev in order to avoid opening random files in the
current working directory.