NAME

cpio − format of cpio archive

DESCRIPTION

The header structure, when the c option is not used, is:

struct {
shorth_magic,
h_dev,
h_ino,
h_mode,
h_uid,
h_gid,
h_nlink,
h_rdev,
h_mtime[2],
h_namesize,
h_filesize[2];
charh_name[h_namesize rounded to word];
} Hdr;

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

sscanf(Chdr,"%6o%6o%6o%6o%6o%6o%6o%6o%11lo%6o%6o%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. The contents of each file is 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

cpio(1), find(1), stat(2). 

May 16, 1980