NAME

cpio − format of cpio archive

DESCRIPTION

The header structure, when the −c option of cpio(1) is not used, is:

struct {
shorth_magic,
h_dev;
ino_t h_ino;
ushorth_mode,
h_uid,
h_gid;
shorth_nlink,
h_rdev,
h_mtime[2],
h_namesize,
h_filesize[2];
charh_name[256];
} Hdr;

When the −c option is used, the header information is described by:

sscanf(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. Applications conforming to the POSIX 1003.1-1988 extended cpio format should always use the -c option.  All applications should note that the maximum size of a pathname is 256 characters.  The contents of each file are recorded in an element of the array of varying length structures, archive, together with other items describing the file. Every instance of h_magic contains the constant 070707 (octal).  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 record of the archive always contains the name TRAILER!!!.  Special files, directories, and the trailer are recorded with h_filesize equal to zero. 

SEE ALSO

stat(2). 
cpio(1), find(1) in the CX/UX User’s Reference Manual. 

CX/UX Programmer’s Reference Manual