HP-UX Reference (11i v3 07/02) - 1 User Commands N-Z (vol 2)

p
pax(1) pax(1)
header structure.
ustar Interchange Format
A ustar archive tape or file shall contain a series of logical records. Each logical record shall be a fixed-
size logical record of 512 bytes. Each file archived shall be represented by a header logical record that
describes the file, followed by zero or more logical records that give the contents of the file. At the end of
the archive file there shall be two 512-octet logical records filled with binary zeros, interpreted as an end-
of-archive indicator. The header logical record shall contain the following fields:
name,prefix
The name and the prefix fields shall produce the pathname of the file. A new pathname shall be
formed, if prefix is not an empty string (its first character is not NUL), by concatenating prefix (up to
the first NUL character), a slash character, and name; otherwise, name is used alone. In this manner,
pathnames up to 256 characters can be supported. If a pathname does not fit in the space provided,
pax shall notify the user of the error, and shall not store any part of the file-header or data on the
medium.
mode
The mode field provides 12 bits encoded in the ISO/IEC 646:1991 standard octal digit representation
to encode the permissions.
uid,gid
The user and group ID of the owner and group of the file, respectively. If
uid or gid is greater than
2097151, a value of -1 will be stored in the respective field of the
ustar
header. If the corresponding
name (user name for uid and group name for gid) also could not be stored in the archive,
pax shall
notify the user of the error but shall include the other attributes of the file and its data on the
medium.
uname,gname
The names of the owner and group of the file, respectively. If the user or group name is longer than 31
characters, it will not be stored in the respective field of the
ustar header. pax
shall notify the
user of the error but shall include the other attributes of the file and its data on the medium.
size
The size of the file in bytes. If the size of the files is greater than or equal to 8GB,
pax shall notify the
user of the error, and shall not store any part of the file-header or data on the medium.
mtime
The modification time of the file at the time it was archived.
typeflag
Specifies the type of file archived. All of the typeflag fields shall be coded in the ISO/IEC 646:1991
standard IRV
0 Represents a regular file.
1 Represents a file linked to another file, of any type, previously archived. The linked-to name
is specified in the linkname field with a NUL-character terminator if it is less than 100 bytes
in length.
2 Represents a symbolic link. The contents of the symbolic link shall be stored in the linkname
field.
3,4 Represents character special files and block special files respectively.
5 Specifies a directory or subdirectory.
6 Specifies a FIFO special file. Note that the archiving of a FIFO file archives the existence of
this file and not its contents.
linkname
The linkname is the pathname of the target of a symbolic or hard link. It is limited to 100 characters.
If the name does not fit in the space provided,
pax shall notify the user of the error, and shall not
attempt to store the link on the medium.
devmajor,devminor
When the typeflag field contains ’3’ or ’4’ the devmajor and devminor fields shall contain the
major and minor numbers of the device respectively.
HP-UX 11i Version 3: February 2007 − 9 − Hewlett-Packard Company 113