MKFS(VIII) 11/1/73 MKFS(VIII) NAME mkfs - construct a file system SYNOPSIS /etc/mkfs special proto DESCRIPTION Mkfs constructs a file system by writing on the special file special according to the directions found in the prototype file 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. The mode token for a file is a 6 character string. The first character specifies the type of the file. (The characters -bcd specify regular, block special, character special and directory files respectively.) The second character of the type is either u or - to specify set-user- id mode or not. The third is g or - for the set-group-id mode. The rest of the mode is a three digit octal number giving the owner, group, and foreigner read, write, execute permissions (see chmod (I)). Two decimal number tokens come after the mode; they specify the user and group ID's of the owner of the file. If the file is a regular file, the next token is a pathname whence the contents and size are copied. If the file is a block or character special file, two decimal number tokens follow which give the major and minor device numbers. If the file is a directory, mkfs makes the entries . and .. and then reads a list of names and (recursively) file specifications for the entries in the directory. The scan is terminated with the token $. If the prototype file cannot be opened and its name consists of a string of digits, mkfs builds a file system with a single empty directory on it. The size of the file system is the value of proto interpreted as a decimal number. The i-list size is the file system size divided by 50. (This corresponds to an average size of three blocks per file.) The boot program is left uninitialized. A sample prototype specification follows: /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 $ $ SEE ALSO file system(V), directory(V), boot procedures(VIII) DIAGNOSTICS There are various diagnostics for syntax errors, inconsistent values, and sizes too small. BUGS It is not possible to initialize a file larger than 64K bytes. The size of the file system is restricted to 64K blocks. There should be some way to specify links.