Copying Files With a Different Header Format

Archives created with the SunOS 5.8 cpio command might not be compatible with older SunOS releases. The cpio command allows you to create archives that can be read with several other formats. You specify these formats using the -H option and one of these arguments:

• crc or CRC - ASCII header with checksum

• ustar or USTAR - IEEE/P1003 Data Interchange

• tar or TAR - tar header and format

• odc - ASCII header with small device numbers

• bar - bar header and format

The syntax for using the header options is:

cpio -o -H header-option < file-list > output-archive

How to Create an Archive for Older SunOS Releases

Use the cpio command to create the archive.

$ cpio -oH odc < file-list > /dev/rmt/n

The -H values have the same meaning for input as they do for output. If the archive was created using the -H option, you must use the same option when the archive is read back in or the cpio command will fail, as shown below.

Example--Creating an Archive for Older SunOS Releases

$ find . -print | cpio -oH tar > /tmp/test
 113 blocks
$ cpio -iH bar < /tmp/test
cpio: Invalid header "bar" specified
USAGE:
        cpio -i[bcdfkmrstuvBSV6] [-C size] [-E file] [-H hdr]
            [-I file [-M msg]] [-R id] [patterns]
        cpio -o[acvABLV] [-C size] [-H hdr] [-O file [-M msg]]
        cpio -p[adlmuvLV] [-R id] directory

When you create an archive using different options, always write the command syntax on the media label along with the names of the files or file system on the archive.

If you do not know which cpio options were used when an archive was created, all you can do is experiment with different combinations of the options to see which ones allow the archive to be read.

See cpio(1) for a complete list of options.

Retrieving Files Created With the bar Command

To retrieve files from diskettes that were archived using the SunOS 4.0/4.1 bar command, use the -H bar option to cpio.

You can use only the -H bar option with -i to retrieve files. You cannot create files with the bar header option.

How to Retrieve bar Files From a Diskette

1. Change to the directory where you want to put the files.

2. Insert the diskette into the drive.

3. Run volcheck to make the diskette available.

   $ volcheck

4. Use the cpio command to retrieve bar files from a diskette.

   All the files on the diskette are copied to the current directory.

   $ cpio -ivH bar < /vol/dev/rdiskette/unlabeled