devreserv(1M) System Administration Commands devreserv(1M)NAMEdevreserv - reserve devices for exclusive use
SYNOPSISdevreserv [ key [device-list...]]
DESCRIPTIONdevreserv 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 partic‐
ular 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 ALSOdevfree(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 reservation
has been canceled. However, processes that do not use device reserva‐
tion 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)