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archives.h(3HEAD)

Name | Description

Name

    archives.h, archives– device header

Description


    /* Magic numbers */
    #define CMN_ASC 0x070701    /* Cpio Magic Number for -c header */
    #define CMN_BIN 070707      /* Cpio Magic Number for Binary header */
    #define CMN_BBS 0143561     /* Cpio Magic Number for Byte-Swap header */
    #define CMN_CRC 0x070702    /* Cpio Magic Number for CRC header */
    #define CMS_ASC "070701"    /* Cpio Magic String for -c header */
    #define CMS_CHR "070707"    /* Cpio Magic String for odc header */
    #define CMS_CRC "070702"    /* Cpio Magic String for CRC header */
    #define CMS_LEN 6           /* Cpio Magic String length */
    /* Various header and field lengths */
    #define CHRSZ   76         /* -H odc size minus filename field */
    #define ASCSZ   110        /* -c and CRC hdr size minus filename field */
    #define TARSZ   512        /* TAR hdr size */
    #define HNAMLEN 256        /* maximum filename length for binary and
                              odc headers */
    #define EXPNLEN 1024      /* maximum filename length for -c and
                             CRC headers */
    #define HTIMLEN 2         /* length of modification time field */
    #define HSIZLEN 2         /* length of file size field */
    /* cpio binary header definition */
    struct hdr_cpio {
           short   h_magic,           /* magic number field */
                   h_dev;             /* file system of file */
           ushort_t  h_ino,           /* inode of file */
                   h_mode,            /* modes of file */
                   h_uid,             /* uid of file */
                   h_gid;             /* gid of file */
           short   h_nlink,           /* number of links to file */
                   h_rdev,            /* maj/min numbers for special files */
                   h_mtime[HTIMLEN],  /* modification time of file */
                   h_namesize,        /* length of filename */
              h_filesize[HSIZLEN];     /* size of file */
         char h_name[HNAMLEN];    /* filename */
    } ;
    /* cpio -H odc header format */
    struct c_hdr {
           char c_magic[CMS_LEN],
                c_dev[6],
                c_ino[6],
                c_mode[6],
                c_uid[6],
                c_gid[6],
                c_nlink[6],
                c_rdev[6],
                c_mtime[11],
                c_namesz[6],
                c_filesz[11],
                c_name[HNAMLEN];
    } ;
    /* -c and CRC header format */
    struct Exp_cpio_hdr {
         char E_magic[CMS_LEN],
              E_ino[8],
              E_mode[8],
              E_uid[8],
              E_gid[8],
              E_nlink[8],
              E_mtime[8],
              E_filesize[8],
              E_maj[8],
              E_min[8],
              E_rmaj[8],
              E_rmin[8],
              E_namesize[8],
              E_chksum[8],
              E_name[EXPNLEN];
    } ;
    /* Tar header structure and format */
    #define TBLOCK 512  /* length of tar header and data blocks */
    #define TNAMLEN     100  /* maximum length for tar file names */
    #define TMODLEN     8    /* length of mode field */
    #define TUIDLEN     8    /* length of uid field */
    #define TGIDLEN     8    /* length of gid field */
    #define TSIZLEN     12   /* length of size field */
    #define TTIMLEN     12   /* length of modification time field */
    #define TCRCLEN     8    /* length of header checksum field */
    /* tar header definition */
    union tblock {
         char dummy[TBLOCK];
         struct header {
             char  t_name[TNAMLEN];     /* name of file */
             char  t_mode[TMODLEN];     /* mode of file */
             char  t_uid[TUIDLEN];      /* uid of file */
             char  t_gid[TGIDLEN];      /* gid of file */
             char  t_size[TSIZLEN];     /* size of file in bytes */
             char  t_mtime[TTIMLEN];    /* modification time of file */
             char  t_chksum[TCRCLEN];   /* checksum of header */
             char  t_typeflag;          /* flag to indicate type of file */
             char  t_linkname[TNAMLEN]; /* file this file is linked with */
             char  t_magic[6];          /* magic string always "ustar" */
             char  t_version[2];        /* version strings always "00" */
             char  t_uname[32];         /* owner of file in ASCII */
             char  t_gname[32];         /* group of file in ASCII */
             char  t_devmajor[8];       /* major number for special files */
             char  t_devminor[8];       /* minor number for special files */
             char  t_prefix[155];       /* pathname prefix */
         } tbuf;
    }
    /* volcopy tape label format and structure */
    #define VMAGLEN 8
    #define VVOLLEN     6
    #define VFILLEN     464
    struct volcopy_label {
         char v_magic[VMAGLEN],
              v_volume[VVOLLEN],
              v_reels,
              v_reel;
         long v_time,
              v_length,
              v_dens,
              v_reelblks,    /* u370 added field */
              v_blksize,     /* u370 added field */
              v_nblocks;     /* u370 added field */
         char v_fill[VFILLEN];
         long v_offset; /* used with -e and -reel options */
         int  v_type;        /* does tape have nblocks field? */
    } ;
    
    /*
     * Define archive formats for extended attributes.
     *
     * Extended attributes are stored in two pieces.
     * 1. An attribute header which has information about
     *    what file the attribute is for and what the attribute
     *    is named.
     * 2. The attribute record itself.  Stored as a normal file type
     *    of entry.
     * Both the header and attribute record have special modes/typeflags
     * associated with them.
     *
     * The names of the header in the archive look like:
     * /dev/null/attr.hdr
     *
     * The name of the attribute looks like:
     * /dev/null/attr.
     *
     * This is done so that an archiver that doesn't understand these formats
     * can just dispose of the attribute records unless the user chooses to
     * rename them via cpio -r or pax -i
     *
     * The format is composed of a fixed size header followed
     * by a variable sized xattr_buf. If the attribute is a hard link
     * to another attribute, then another xattr_buf section is included
     * for the link.
     *
     * The xattr_buf is used to define the necessary "pathing" steps
     * to get to the extended attribute.  This is necessary to support
     * a fully recursive attribute model where an attribute may itself
     * have an attribute.
     *
     * The basic layout looks like this.
     *
    *     --------------------------------
     *     |                              |
     *     |         xattr_hdr            |
     *     |                              |
     *     --------------------------------
     *     --------------------------------
     *     |                              |
     *     |        xattr_buf             |
     *     |                              |
     *     --------------------------------
     *     --------------------------------
     *     |                              |
     *     |      (optional link info)    |
     *     |                              |
     *     --------------------------------
     *     --------------------------------
     *     |                              |
     *     |      attribute itself        |
     *     |      stored as normal tar    |
     *     |      or cpio data with       |
     *     |      special mode or         |
     *     |      typeflag                |
     *     |                              |
     *     --------------------------------
     *
     */
    #define XATTR_ARCH_VERS "1.0"
    
    /*
     * extended attribute fixed header
     *
     * h_version            format version.
     * h_size               size of header + variable sized data sections.
     * h_component_len      Length of entire pathing section.
     * h_link_component_len Length of link component section.  Again same 
     *                      definition as h_component_len.
     */
    struct xattr_hdr {
            char    h_version[7];
            char    h_size[10];
            char    h_component_len[10]; /* total length of path component */
            char    h_link_component_len[10];
    };
    
    /*
     * The name is encoded like this:
     * filepathNULattrpathNUL[attrpathNULL]...
     */
    struct xattr_buf {
            char    h_namesz[7];  /* length of h_names */
            char    h_typeflag;   /* actual typeflag of file being archived */
            char    h_names[1];   /* filepathNULattrpathNUL... */
    };
    
    /*
     * Special values for tar archives
     */
    
    /*
     * typeflag for tar archives.
     */
    
    /*
     * Attribute hdr and attribute files have the following typeflag
     */
    #define _XATTR_HDRTYPE          'E'
    
    /*
     * For cpio archives the header and attribute have
     * _XATTR_CPIO_MODE ORED into the mode field in both
     * character and binary versions of the archive format
     */
    #define _XATTR_CPIO_MODE        0xB000
SunOS 5.11  Last Revised 22 Oct 2007

Name | Description