cpio(F)                         19 June 1992                         cpio(F)


 Name

    cpio - format of cpio archive

 Description

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

       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 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.hmtime and Hdr.hfilesize,
    respectively.  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 hmagic contains the con-
    stant 070707 (octal).  The items hdev through hmtime have meanings
    explained in stat(S).  The length of the null-terminated path name
    hname, including the null byte, is given by hnamesize.

    The last record of the archive always contains the name ``TRAILER!!!''.
    Special files, directories, and the trailer are recorded with hfilesize
    equal to zero.

 See also

    cpio(C), find(C), stat(S)

 Standards conformance

    cpio is conformant with:

    AT&T SVID Issue 2;
    and X/Open Portability Guide, Issue 3, 1989.