Hi
can any one tell me if i can encrypt a file using tar or tar bzip/gzip or zip command while taking a backup just as i can do with vi

you can tar something, encrypt it then compress it using bzip/gzip, or tar something, compress it and encrypt it. According to the tar manpage, it is not supported directly, but based on the way tar and gz/bz2 work, it is simply an other layer in between. You are free to use one of many crypt tools available.

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Encrypted data should not have any discernible patterns so should not compress well. If that theory is correct, compression followed by encryption should produce a smaller file than encryption followed by compression.

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You may want to do this---

Enter password when prompted.

You may remove the original file or delete them after gpg encrypted file is made. Or include deletion within command:

this one creates an encrypted archive and removes the unencrypted original.

From thence you may create a script to be envoked when encrypting file.

Hope that helps. Good luck.

tar cf - /path/to/data | 7z a -si archivename.tar.7z


http://www.commandlinefu.com/command...7z-compression

The post also has some additions useful.


"What others think

some newer versions of tar support the '--lzma' option

LZMA is the same type of compression used by 7zip

This is a cleaner option, though I suppose it is only supported by newer versions of tar which could be a problem...
tar c --lzma /path/to/data > archivename.tar.lzma
Comment by infinull 174 weeks and 4 days ago

According to google, GNU tar supports the lzma option since tar 1.20. Starting in tar 1.22 -J (capital 'j') means --xz and not --lzma.
Comment by bwoodacre 174 weeks and 3 days ago
"

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Thank you jefro. I did not know that.
My tar version=1.26 the --lzma and -J options are already available. I have tried tarring with lzma, the resulting file cannot be stat by 'fileroller' while the resultant file of -J option is easily handled by the same GUI reader. Both results extracted by the same switch. I observe that --lzma switch is entered only after the file name tar -cf foo.tar.lz foo --lzma.

Thank you again.

I learn something new everyday here.

tar the file first like you normally would

note you do not need the excludes.conf, it is just there as an option if you want to tar portions of a directory

to encrypt you can use something as simple as this:

there ya go. do not forget the password or you will never get access to the encrypted tarball again.

you can also use && to combine that into one command line. so it will first make the tarball, then encrypt it.