devreserv(1M) System Administration Commands devreserv(1M)
NAME
devreserv - reserve devices for exclusive use
SYNOPSIS
devreserv [ key [device-list...]]
DESCRIPTION
devreserv reserves devices for exclusive use. When the device is no longer required, use devfree to release it.
devreserv reserves at most one device per device-list. Each list is searched in linear order until the first available device is found. If
a device cannot be reserved from each list, the entire reservation fails.
When devreserv is invoked without arguments, it lists the devices that are currently reserved and shows to which key it was reserved. When
devreserv is invoked with only the key argument, it lists the devices that are currently reserved to that key.
OPERANDS
The following operands are supported:
device-list Defines a list of devices that devreserv will search to find an available device. The list must be formatted as a single
argument to the shell.
key Designates a unique key on which the device will be reserved. The key must be a positive integer.
EXAMPLES
Example 1: Reserving a Floppy Disk and a Cartridge Tape
The following example reserves a floppy disk and a cartridge tape:
$ key=$$
$ echo "The current Process ID is equal to: $key"
The Current Process ID is equal to: 10658
$ devreserv $key diskette1 ctape1
Example 2: Listing All Devices Currently Reserved
The following example lists all devices currently reserved:
$ devreserv
disk1 2423
diskette1 10658
ctape1 10658
Example 3: Listing All Devices Currently Reserved to a Particular Key
The following example lists all devices currently reserved to a particular key:
$ devreserv $key
diskette1
ctape1
EXIT STATUS
The following exit values are returned:
0 Successful completion.
1 Command syntax was incorrect, an invalid was option used, or an internal error occurred.
2 Device table or device reservation table could not be opened for reading.
3 Device reservation request could not be fulfilled.
FILES
/etc/device.tab
/etc/devlkfile
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Availability |SUNWcsu |
+-----------------------------+-----------------------------+
SEE ALSO
devfree(1M), attributes(5)
NOTES
The commands devreserv and devfree are used to manage the availability of devices on a system. Their use is on a participatory basis and
they do not place any constraints on the actual access to the device. They serve as a centralized bookkeeping point for those who wish to
use them. Devices which have been reserved cannot be used by processes which utilize the device reservation functions until the reserva-
tion has been canceled. However, processes that do not use device reservation may use a device that has been reserved since such a process
would not have checked for its reservation status.
SunOS 5.10 5 Jul 1990 devreserv(1M)