z/OS V1R9.0 UNIX System Services Command ... - Christian Grothoff

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cpio
After the header information, namesize bytes of pathname are stored. namesize
includes the null byte of the end of the pathname. After this, filesize bytes of the file
contents are recorded.
Binary headers contain the same information in 2-byte (short) and 4-byte (long)
integers as follows:
Bytes Field Names
2 magic
2 dev
2 ino
2 mode
2 uid
2 gid
2 nlink
2 rdev
2 mtime
2 namesize
2 filesize
After the header information comes the filename, with namesize rounded up to the
nearest 2-byte boundary. Then the file contents appear as in the ASCII archive. The
byte ordering of the 2- and 4-byte integers in the binary format is
machine-dependent and thus portability of this format is not easily guaranteed.
Related Information
The compress, cpio, pax, and tar commands
magic — Format of the /etc/magic file
Description
The file command uses the /etc/magic file in its attempt to identify the type of a
binary file. Essentially, /etc/magic contains templates showing what different types
of files look like.
The magic file contains lines describing magic numbers, which identify particular
types of files. Lines beginning with a > or & character represent continuation lines
to a preceding main entry:
> If the file command finds a match on the main entry line, these additional
patterns are checked. Any pattern that matches is used. This may generate
additional output; a single blank separates each matching line’s output if
any output exists for that line.
& If the file command finds a match on the main entry line, and a following
continuation line begins with this character, that continuation line’s pattern
must also match, or neither line is used. Output text associated with any
line beginning with the & character is ignored.
Each line consists of four fields, separated by one or more tabs:
(a) The first field is a byte offset in the file, consisting of an optional offset
operator and a value. In continuation lines, the offset immediately follows a
continuation character.
912 z/OS V1R9.0 UNIX System Services Command Reference
If no offset operator is specified, then the offset value indicates an offset
from the beginning of the file.