MPE/iX System Utilities Reference Manual (32650-90908)

Chapter 14
MKNOD
Operation
142
Operation
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]"
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:
mknod "myfifo p"
To create a device link file for LDEV 7:
mknod "/dev/tape7 c,0,7"
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"
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