mknod(8)mknod(8)NAMEmknod - Creates a special file
/usr/sbin/mknod special_file [b major_device# minor_device# | c
/usr/sbin/mknod filename p
Indicates that the special file corresponds to a block-oriented device
(disk or tape) Indicates that the special file corresponds to a charac‐
ter-oriented device Creates named pipes (FIFOs)
The mknod command makes a directory entry. The first argument is the
name of the special device file. Select a name that is descriptive of
The mknod command has two forms. In the first form, the second argument
is the b or c flag. The last two arguments are numbers specifying the
major_device, which helps the operating system find the device driver
code, and the minor_device, the unit drive, or line number, which may
be either decimal or octal.
The assignment of major device numbers is specific to each system. You
can determine the device numbers by examining the conf.c system source
file. If you change the contents of the conf.c file to add a device
driver, you must rebuild the kernel.
In the second form of mknod, you use the p flag to create named pipes
A user who is root can create a character or block special file.
To create the special file for a new drive, /dev/disk/dsk20, with a
major device number of 1 and a minor device number of 2, enter: mknod
/dev/disk/dsk20 b 1 2
This command creates the special file, /dev/disk/dsk20, which is
a block special file with major device number 1 and minor device
number 2. To create a pipe named fifo, enter: mknod fifo p
This command creates the pipe fifo, which is not necessarily in
the current directory.
Specifies the command path Specifies the system device numbers specifi‐