Difference between revisions of "Linux/command/mknod"

Latest revision as of 20:42, 5 January 2018

computing: software: operating systems: Linux: mknod

Questions

What happens if mknod is invoked with just a name and no options, as in "mknod /dev/loop0"?

Manpage

Name

mknod - make block or character special files

Synopsis

mknod [OPTION]... NAME TYPE [MAJOR MINOR]

Description

Create the special file NAME of the given TYPE. TYPE can be a FIFO, character special file, or block special file. An exit status of zero indicates success, and a nonzero value indicates failure

The term "special file" (not to be confused with "Special File Type") has a technical meaning on Unix: something that can generate or receive data. Usually this corresponds to a physical piece of hardware, e.g., a printer or a disk. (These files are typically created at system-configuration time.) The "mknod" command is what creates files of this type. Such devices can be read either a character at a time or a "block" (many characters) at a time, hence we say there are "block special" files and "character special" files.

Mandatory arguments to long options are mandatory for short options too.

-m, --mode=MODE

set permission mode (as in chmod), not a=rw -umask. Uses `a=rw' minus the bits set in the umask as

the point of departure. (Editor's note: these last two bits of information seem to flatly contradict each other; the first is from MAN, the second is from info. It's also unclear.)

--help

display this help and exit

--version

output version information and exit Both MAJOR and MINOR must be specified when TYPE is b, c, or u (i.e. the special file is block or character type), and they must be omitted when TYPE is p. If MAJOR or MINOR begins with 0x or 0X, it is interpreted as hexadecimal; otherwise, if it begins with 0, as octal; otherwise, as decimal.

TYPE may be:

b
create a block (buffered) special file
c, u
create a character (unbuffered) special file
p
create a FIFO

Author

Written by David MacKenzie.

Reporting Bugs

Report bugs to <bug-coreutils@gnu.org>.

Copyright

Edit History

2005-10-14 Cleaned up after being imported into htyp
2005-06-25 This page created from a combination of MAN page and info coreutils (both in Ubuntu hoary).

@@ Line 1: / Line 1: @@
-[[Category:Linux
+{{linuxcmdhdr|mknod}}[[Category:manpages]]
-Shell Commands]]
+==Questions==
-[[Techniques]]: [[Linux]]: [[Linux:mknod|mknod]]
+*What happens if mknod is invoked with just a name and no options, as in "mknod /dev/loop0"?
-==Documentation==
+==Manpage==
 ===Name===
-*[[Linux:mknod|mknod]] - make block or character special files
+*{{linuxcmd|mknod}} - make block or character special files
 ===Synopsis===
-*[[Linux:mknod|mknod]] [''OPTION'']... ''NAME TYPE'' [''MAJOR MINOR'']
+* {{linuxcmd|mknod}} [''OPTION'']... ''NAME TYPE'' [''MAJOR MINOR'']
 ===Description===
-Create the special file NAME of the given TYPE. TYPE can be a FIFO,
+Create the special file NAME of the given TYPE. TYPE can be a FIFO, character special file, or block special file.
-character special file, or block special file.
+An exit status of zero indicates success, and a nonzero value indicates failure
-An exit status of zero indicates success, and a nonzero value indicates
-failure
+The term "special file" (not to be confused with "Special File Type") has a technical meaning on Unix: something that can generate or receive data. Usually this corresponds to a physical piece of hardware, e.g., a printer or a disk. (These files are typically created at system-configuration time.) The "{{linuxcmd|mknod}}" command is what creates files of this type. Such devices can be read either a character at a time or a "block" (many characters) at a time, hence we say there
-The term "special file" (not to be confused with "Special File Type")
-has a technical meaning on Unix: something that can generate or receive
-data. Usually this corresponds to a physical piece of hardware, e.g., a
-printer or a disk. (These files are typically created at
-system-configuration time.) The `[[Linux:mknod|mknod]]' command is what
-creates files of this type. Such devices can be read either a character
-at a time or a "block" (many characters) at a time, hence we say there
 are "block special" files and "character special" files.
-Mandatory arguments to long options are mandatory for short options
-too. *'''-m, --mode'''=''MODE''
+Mandatory arguments to long options are mandatory for short options too.
-:set permission mode (as in [[Linux:chmod|chmod]]), not a=rw -
+*'''-m, --mode'''=''MODE''
-[[Linux:umask|umask]]. Uses `a=rw' minus the bits set in the umask as
+:set permission mode (as in [[chmod]]), not a=rw -[[Linux:umask|umask]]. Uses `a=rw' minus the bits set in the umask as
-the
+the point of departure. (Editor's note: these last two bits of information
-point of departure. (Editor's note: these last two bits of information
 seem to flatly contradict each other; the first is from MAN, the second
-is from info.)
+is from info. It's also unclear.)
 *'''--help'''
-:display this help and exit *'''--version'''
+:display this help and exit
-:output version information and exit Both MAJOR and MINOR must be
+*'''--version'''
-specified when TYPE is b, c, or u (i.e. the special file is block or
+:output version information and exit Both MAJOR and MINOR must be specified when TYPE is b, c, or u (i.e. the special file is block or character type), and they must be omitted when TYPE is p. If MAJOR or MINOR begins with 0x or 0X, it is interpreted as hexadecimal; otherwise, if it begins with 0, as octal; otherwise, as decimal.
-character type), and they must be omitted when TYPE is p. If MAJOR or
-MINOR begins with 0x or 0X, it is interpreted as hexadecimal;
+''TYPE'' may be:
-otherwise, if it begins with 0, as octal; otherwise, as decimal. TYPE
+*'''b'''
-may be: '''b'''
+*:create a block (buffered) special file
-:create a block (buffered) special file '''c''', '''u'''
+*'''c''', '''u'''
-:create a character (unbuffered) special file '''p'''
+*:create a character (unbuffered) special file
-:create a FIFO ===Author===
+*'''p'''
-Written by David MacKenzie. ===Reporting Bugs===
+*:create a FIFO
-Report bugs to <bug-coreutils@gnu.org>. ===Copyright===
-Copyright &copy; 2004 Free Software Foundation, Inc. This is free
+===Author===
-software; see the source for copying conditions. There is NO warranty;
+Written by David MacKenzie.
-not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+===Reporting Bugs===
+Report bugs to <bug-coreutils@gnu.org>.
+===Copyright===
+Copyright &copy; 2004 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 ===See Also===
-The full documentation for mknod is maintained as a Texinfo manual. If
+The full documentation for mknod is maintained as a Texinfo manual. If the info and mknod programs are properly installed at your site, the command info coreutils mknod should give you access to the complete manual.
-the info and mknod programs are properly installed at your site, the
-command info coreutils mknod should give you access to the complete
-manual.
 ==Edit History==
-* '''2005-06-25''' This page created from a combination of MAN page and
+* '''2005-10-14''' Cleaned up after being imported into htyp
-info coreutils (both in Ubuntu hoary).
+* '''2005-06-25''' This page created from a combination of MAN page and info coreutils (both in Ubuntu hoary).