MKNOD determines how to create the files based on the arguments passed
to the program. When creating a device link or streams (character-type) file,
you must enter both the major and minor numbers.
To create a device link file, enter a major number of 0 and the
LDEV number of the device as the minor number.
To create a streams file, enter a major number greater than 0.
Syntax
mknod "name c|p major minor [link_name]"
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Parameters
- name
Creates a special or fifo file including the program name in the
pathname.
- c|p
Creates a device link file or streams file if this argument is 'c'
(character type).
Creates a fifo file or pipe if this argument is 'p'.
- major
Major number. The following major numbers are valid:
- 0
Creates a device link. The minor number represents the LDEV number.
- 1-254
Creates a streams file.
- minor
Minor device type. This is used in conjunction with the major
number option to provide a UNIX compatible device specification. The
interpretion of the minor number is dependent on the value of the major
number. If the major number is 0, then this number represents a LDEV
number. If the major number is > 0, then this number represents a
streams connection to a driver.
- link_name
Creates the streams file with a link_name. This name
is an eight-character MPE link_name (from the NMMGR link screen).
When the special file is created, it can be accessed through the HPFOPEN
intrinsic and the C library "open" interface. The 0_NONBLOCK option
can be specified using open.
MKNOD sets a CI variable mknodvar with the value 0 if successful.
If errors occur, it returns the file system error status.
To create a fifo file called MYFIFO:
To create a device link file for LDEV 7:
To create a streams file with a link_name of DTSLINK, a major
number of 1, and a minor number of 10:
mknod "strmfile c,1,10,dtslink"
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You can use the LISTFILE command to display special files. For example:
LISTFILE /dev/@,2
PATH= /dev/./
CODE -------------LOGICAL RECORD----------------SPACE----- FILENAME
SIZE TYPE EOF LIMIT R/B SECTORS #X MX
128W FBf 0 1 1 0 0 * MYFIFO
128W FBs 0 1 1 0 0 * STRMFILE
128W FBd 0 1 1 0 0 * tape7
:LISTFILE /dev/tape7,5
**********************
FILE: /dev/tape7
FILE CODE : 0 FOPTIONS: BINARY,FIXED,NOCCTL,DEVICE LINK
BLK FACTOR: 1 OWNER : **
REC SIZE: 256 (BYTES) GROUP ID: **
BLK SIZE: 256 (BYTES) SECURITY--READ :
EXT SIZE: 0 (SECT) WRITE :
NUM REC: 0 APPEND :
NUM SEC: 0 LOCK :
NUM EXT: 0 EXECUTE:
MAX REC: 1 **SECURITY IS ON
FLAGS : NO ACCESSORS
NUM LABELS: 0 CREATED : THU, AUG 24, 1993 3:12 PM
MAX LABELS: 0 MODIFIED: THU, AUG 24, 1993 3:12 PM
DISC DEV #: 1 ACCESESED:THU, AUG 24, 1993 3:12 PM
SEC OFFSET: 0 LABEL ADDR: **
VOLNAME : MPEXL_SYSTEM_VOUME_SET:MEMBER1
DEV TYPE : DEVICE LINK
LDEV : 7 IO CLASS: TAPE
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Additional Discussion |
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For more information on streams and device link files, refer to the
HPDEVCREATE intrinsic in the MPE/iX Intrinsics Reference Manual (32650-90028).
