mkfs.8

UNIX v6源代码 这几乎是最经典的unix版本 unix操作系统设计和莱昂氏unix源代码分析都是用的该版

.th MKFS VIII 11/1/73
.sh NAME
mkfs \*- construct a file system
.sh SYNOPSIS
.bd /etc/mkfs
special
proto
.sh DESCRIPTION
.it Mkfs
constructs a file system
by writing on the special file
.it special
according to the directions
found in
the prototype file
.it proto.
The prototype file
contains tokens separated by spaces or
new lines.
The first token is the name of a file
to be copied onto block zero as
the bootstrap program
(see boot procedures (VIII)).
The second token is a number specifying the
size of the created file system.
Typically it will be the number of blocks on the device,
perhaps diminished
by space for swapping.
The next token is the i-list size in blocks
(remember there are 16 i-nodes per block).
The next set of tokens comprise the specification
for the root file.
File specifications consist of tokens
giving the mode,
the user-id,
the group id,
and the initial contents of the file.
The syntax of the contents field
depends on the mode.
.s3
The mode token for a file is a 6 character string.
The first character
specifies the type of the file.
(The characters
.bd \*-bcd
specify regular, block special,
character special and directory files
respectively.)
The second character of the type
is either
.bd u
or
.bd \*-
to specify set-user-id mode or not.
The third is
.bd g
or
.bd \*-
for the set-group-id mode.
The rest of the mode
is a three digit octal number giving the
owner, group, and other read, write, execute
permissions (see
.it chmod
(I)).
.s3
Two decimal number
tokens come after the mode; they specify the
user and group ID's of the owner of the file.
.s3
If the file is a regular file,
the next token is a pathname
whence the contents and size are copied.
.s3
If the file is a block or character special file,
two decimal number tokens
follow which give the major and minor device numbers.
.s3
If the file is a directory,
.it mkfs
makes the entries \fB.\fR and \fB..\fR
and then
reads a list of names and
(recursively)
file specifications for the entries
in the directory.
The scan is terminated with the
token \fB$\fR.
.s3
If the prototype file cannot be opened and
its name consists of a string of digits,
.it mkfs
builds a file system with a single
empty directory on it.
The size of the file system is the value
of
.it proto
interpreted as a decimal number.
The i-list size is the file system size
divided by
43 plus the size divided by 1000.
(This corresponds to an average size of
three blocks per file
for a 4000 block file system and
six blocks per file at 40,000.)
The boot program is left uninitialized.
.s3
A sample prototype specification follows:
.s3
.nf
.in +5
/usr/mdec/uboot
4872 55
d\*-\*-777 3 1
usr	d\*-\*-777 3 1
	sh	\*-\*-\*-755 3 1 /bin/sh
	ken	d\*-\*-755 6 1
		$
	b0	b\*-\*-644 3 1 0 0
	c0	c\*-\*-644 3 1 0 0
	$
$
.in -5
.fi
.sh "SEE ALSO"
file system (V),
directory (V),
boot procedures (VIII)
.sh BUGS
It is not possible to initialize a file larger than
64K bytes.
.br
The size of the file system is restricted to
64K blocks.
.br
There should be some way to specify links.