2017-10-21 06:17:45 +00:00
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Strangely enough I had the need to determine if it was possible to create a
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valid but empty tar file. Turns out it is. The method varies slightly depending
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on your flavour of tar program, here's how to do it on three of the big ones:
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2010-03-11 20:30:27 +00:00
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<strong>BSD</strong>
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<code>tar cvf empty.tar --from-file /dev/null</code>
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<strong>GNU (Linux)</strong>
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<code>tar cvf empty.tar --files-from /dev/null</code>
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<strong>Solaris</strong>
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<code>tar cvf empty.tar -I /dev/null</code>
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2017-10-21 06:17:45 +00:00
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<strong>MinGW / MSYS</strong>
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<code>tar cvf empty.tar --files-from NUL</code>
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Thanks to Paul Bußmann for the MSYS suggestion.
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Now if you wondering why I would want this, here's the explanation. I work on a
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batch processing system that processes files delivered from other systems. In
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some cases its necessary to wait for a file to arrive but give up after some
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time. In order to give up we copy an empty file (automatically) so that the
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processing proceeds normally. Ordinarily this is an empty plain text file but
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for the system I'm working on I'm expecting a tar file, hence the need for an
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empty one.
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