cpio(4) DG/UX R4.11 cpio(4)
NAME
cpio - format of cpio archive
DESCRIPTION
When cpio(1) is used on a generic DG/UX system with the -o option
(with the -oZ options on a system with DG/UX information security)
but not the -c option, the header structure of the resulting cpio
archive is as follows:
struct hdrcpio {
short hmagic,
hdev;
ushort hino,
hmode,
huid,
hgid;
short hnlink,
hrdev,
hmtime[2],
hnamesize,
hfilesize[2];
char hname[hnamesize rounded to word];
} Hdr;
When the -c option is used (-cZ options on a system with DG/UX
information security), the header information is described by:
sscanf(Chdr,"%6o%6o%6o%6o%6o%6o%6o%6o%11lo%6o%11lo%s",
&Hdr.hmagic, &Hdr.hdev, &Hdr.hino, &Hdr.hmode,
&Hdr.huid, &Hdr.hgid, &Hdr.hnlink, &Hdr.hrdev,
&Longtime, &Hdr.hnamesize, &Longfile, &Hdr.hname);
Longtime and Longfile are equivalent to Hdr.hmtime and
Hdr.hfilesize, respectively. The contents of each file are recorded
in an element of the array of varying length structures, archive,
with other items describing the file. Every instance of hmagic
contains the constant 070707 (octal). The items hdev through
hmtime have meanings explained in stat(2). The length of the null-
terminated pathname hname, including the null byte, is given by
hnamesize.
The last record of the archive always contains the name TRAILER!!!.
Special files, directories, and the trailer are recorded with
hfilesize equal to zero.
Information Security Features
On a system with DG/UX information security, the following
information applies to trusted cpio binary archives.
The trusted binary format constants and structures are defined in
<dgtarchives.h>.
All records in the trusted binary format are aligned to 32-bit word
boundaries.
The trusted binary format consists of a site security attribute
section followed by one or more file sections. The site security
attribute section is written to the output file every time cpio -o is
invoked. The site security attribute section consists of a header,
optionally followed by a number of attributes:
typedef
struct {
unsigned short tmagic; /* SECBHDRMAGIC */
dgtcpiobinhdrtype ttype; /* SECBHDRHDR0 */
dgtcpiobinhdrrev trev; /* SECBHDRREVCURRENT */
short tnattrs;
}
/*<----------------*/
dgtcpiobinhdr;
/*>----------------*/
tnattrs is the number of site security attributes that follow the
site security header. A site security attribute consists of an
attribute header record which describes the attribute and its length
in bytes. The attribute itself immediately follows the attribute
header record.
typedef
struct {
char Ttype[8];
char Tsize[8];
}
/*<-------------*/
dgtcpioattr;
/*>-------------*/
A file section consists of an identifying header, followed by a
second informational header optionally followed by a number of
attributes, the pathname and finally the file contents.
typedef
struct {
unsigned short tmagic; /* SECBHDRMAGIC */
dgtcpiobinhdrtype ttype; /* SECBHDRHDR0 */
dgtcpiobinhdrrev trev; /* SECBHDRREVCURRENT */
short tnattrs;
}
/*<----------------*/
dgtcpiobinhdr;
/*>----------------*/
typedef
struct {
devt tdev;
inot tino;
modet tmode;
uidt tuid;
gidt tgid;
nlinkt tnlink;
devt trdev;
timet tmtime;
/*
* The pathname immediately follows the last attribute
* following this header.
*/
ssizet tnamesize;
/*
* The file contents should immediately follow the pathname.
*/
dgtcpiofilesizet tfilesize;
unsigned char tufiasubtype;
unsigned char tufiasecpattrs;
unsigned char reservedbyte[2];
modet textendedmode;
unsigned long tmaxcpdblocks;
unsigned long tmaxcpdfilenodes;
}
/*<-------------------*/
dgtcpiobinhdrest;
/*>-------------------*/
dgtcpiobinhdr.tnattrs is the number of file security attributes
that follow the second (informative) file section header. A file
security attribute consists of an attribute header record which
describes the attribute and its length in bytes. The file security
attribute immediately follows the file security attribute header
record.
typedef
struct {
char Ttype[8];
char Tsize[8];
}
/*<-------------*/
dgtcpioattr;
/*>-------------*/
The pathname follows (dg_tcpio_bin_hdrest.t_namesize bytes long),
followed by the file contents (dg_tcpio_bin_hdrest.t_filesize bytes
long).
FILES
/usr/include/archives.h
/usr/include/dgtarchives.h (with DG/UX information security only)
SEE ALSO
cpio(1), stat(2).
Licensed material--property of copyright holder(s)