usr/src/old/cpio/cpioformat.5

.\"     @(#)cpioformat.5        5.2 (Berkeley) %G%
.\"
.TH CPIO 5 ""
.UC 7
.SH NAME
cpio - format of cpio archive
.SH DESCRIPTION
The header structure, when the -c option of cpio(1) is not used, is:
.sp 1
.nf
        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;
.sp 2
When the -c option is used, the header information is described by:
.sp
        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);
.fi
.sp
Longtime and Longfile are equivalent to Hdr.h_mtime and
Hdr.h_filesize, respectively.  The contents of each file are
recorded in an element of the array of varying lenght
structures, archive, together with other items describing
the file.  Every instance of h_magic contains the constant
070707 (octal).  The itimes h_dev through h_mtime have
meanings explained in stat(2).  The length of the null-
terminated path name H_name, icluding the null byte, is
given by h_namesize.
.sp
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.
.SH SEE ALSO
cpio(1), find(1), stat(2)