cam_get_device, cam_open_device: make behavior simpler and more deterministic

Remove or re-work support for the several features from the past:
- remove incomplete support for trimming slice/partition names
- remove mapping from old device names "sd" and "st"
- remove whitespace trimming
- remove unconditional skipping of leading 'r' in a device name
- skip leading 'n' or 'e' only if the following device name matches
  a list of known devices that support no-rewind and eject-on-close
  features; currently this is only sa(4)
- reflect the above changes in comments in code and in cam(3)
- remove a note cautioning against use of cam_get_device and
  cam_open_device in cam(3)

Reviewed by:	mjacob

1 files changed, 2 insertions, 12 deletions

diff --git a/lib/libcam/cam.3 b/lib/libcam/cam.3
index 25328c2..c11d8fd 100644
--- a/lib/libcam/cam.3
+++ b/lib/libcam/cam.3
@@ -190,12 +190,6 @@ into a device name and unit number.
 Once the device name and unit number
 are determined, a lookup is performed to determine the passthrough device
 that corresponds to the given device.
-.Fn cam_open_device
-is rather simple to use, but it is not really suitable for general use
-because its behavior is not necessarily deterministic.
-Programmers writing
-new applications should make the extra effort to use one of the other open
-routines documented below.
 .Pp
 .Fn cam_open_spec_device
 opens the
@@ -354,19 +348,15 @@ respectively.
 can handle strings of the following forms, at least:
 .Pp
 .Bl -tag -width 1234 -compact
-.It /dev/foo0a
-.It /dev/foo1s2c
+.It /dev/foo1
 .It foo0
-.It foo0a
-.It nfoo0
+.It nsa2
 .El
 .Pp
 .Fn cam_get_device
 is provided as a convenience function for applications that need to provide
 functionality similar to
 .Fn cam_open_device .
-Programmers are encouraged to use more deterministic methods of obtaining
-device names and unit numbers if possible.
 .Sh RETURN VALUES
 .Fn cam_open_device ,
 .Fn cam_open_spec_device ,