CPIO(5) CPIO(5)
NAME
cpio - format of cpio archive
DESCRIPTION
The archived files are recorded consecutively, each preceded
by a header. The header structure, when the -c option of
cpio(1) is not used, is:
typdef unsigned short ushort;
struct {
short h_magic,
h_dev;
ushort h_ino,
h_mode,
h_uid,
h_gid;
short h_nlink,
h_rdev,
h_mtime[2],
h_namesize,
h_filesize[2];
char h_name[h_namesize rounded to word];
} Hdr;
When the -c option is used, the header information is print-
able, as described by the printf(3) call
printf(Chdr, "%6o%6o%6o%6o%6o%6o%6o%6o%11lo%6o%11lo%s",
Hdr.h_magic, Hdr.h_dev, Hdr.h_ino, Hdr.h_mode,
Hdr.h_uid, Hdr.h_gid, Hdr.h_nlink, Hdr.h_rdev,
Longtime, Hdr.h_namesize, Longfile, Hdr.h_name
`Longtime' and `Longfile' are equivalent to `Hdr.h_mtime'
and `Hdr.h_filesize', respectively. Every instance of
`h_magic' contains the octal constant `070707'. The items
`h_dev' through `h_mtime' have meanings explained in
stat(2). The length of the null-terminated path name
`h_name', including the null byte, is given by `h_namesize'.
The last element of the archive is a dummy entry for the
name TRAILER!!!, with padding to a multiple of 512 bytes.
Special files, directories, and the trailer are recorded
with `h_filesize' equal to zero.
SEE ALSO
cpio(1), find(1), stat(2).