1.\" Copyright 1991 The Regents of the University of California. 2.\" All rights reserved. 3.\" 4.\" %sccs.include.redist.roff% 5.\" 6.\" @(#)cpioformat.5 5.3 (Berkeley) 05/10/91 7.\" 8.Dd 9.Dt CPIO 5 10.Os 11.Sh NAME 12.Nm cpio 13.Nd format of cpio archive 14.Sh DESCRIPTION 15The header structure, when the 16.Fl c 17option of 18.Xr cpio 1 19is not used, is: 20.Bd -literal -offset indent 21struct { 22 short h_magic, 23 h_dev; 24 ushort h_ino, 25 h_mode, 26 h_uid, 27 h_gid; 28 short h_nlink, 29 h_rdev, 30 h_mtime[2], 31 h_namesize, 32 h_filesize[2]; 33 char h_name[h_namesize rounded to word]; 34} Hdr; 35.Ed 36.Pp 37When the 38.Fl c 39option is used, the header information is described by: 40.Bd -literal -offset indent 41sscanf(Chdr,"%6o%6o%6o%6o%6o%6o%6o%6o%11lo%6o%11lo%s", 42&Hdr.h_magic, &Hdr.h_dev, &Hdr.h_ino, &Hdr.h_mode, 43&Hdr.h_uid, &Hdr.h_gid, &Hdr.h_nlink, &Hdr.h_rdev, 44&Longtime, &Hdr.h_namesize,&Longfile,Hdr.h_name); 45.Ed 46.Pp 47.Fa Longtime 48and 49.Fa Longfile 50are equivalent to 51.Fa Hdr.h_mtime 52and 53.Fa Hdr.h_filesize , 54respectively. 55The contents of each file are 56recorded in an element of the array of varying lenght 57structures, archive, together with other items describing 58the file. 59Every instance of 60.Fa h_magic 61contains the constant 62070707 (octal). 63The itimes 64.Fa h_dev 65through 66.Fa h_mtime 67have 68meanings explained in 69.Xr stat 2 . 70The length of the null-terminated path name 71.Fa H_name , 72icluding the null byte, is 73given by 74.Fa h_namesize . 75.Pp 76The last record of the archive always contains the name 77TRAILER!!!. Special files, directories, and the trailer are 78recorded with 79.Fa H_filesize 80equal to zero. 81.Sh SEE ALSO 82.Xr cpio 1 , 83.Xr find 1 , 84.Xr stat 2 85.Sh HISTORY 86A 87.Xr cpio 1 88command appeared in 89.At V . 90This file format is derived from the 91.At V 92sources which were contributed to the public domain by AT&T. 93