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Can anyone tell me if it's possible to pipe | this without having to create a physical file anywhere between A and B.tar.gz?

This is what I'm trying to do:

  1. File A
  2. Rename A to B
  3. Tar B.tar
  4. gzip -9 B.tar.gz

So for example:

cp A B | tar cvf - B | gzip -9 B.tar.gz
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migrated from stackoverflow.com Aug 20 '11 at 2:04

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why would you like to pipe cp A B ? –  Dor Aug 5 '11 at 11:30
    
rename is mv. –  Karoly Horvath Aug 5 '11 at 11:44
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Please explain why you would like to copy A to B first. –  speakr Jun 21 '12 at 10:23
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2 Answers

The following examples can be used to avoid creating intermediary files:

tar with gzip:

tar cf - A | gzip -9 > B.tar.gz

gzip without tar:

gzip -9c A > B.gz

tar without gzip:

tar cf B.tar A

Renaming (moving) A to B first doesn't make sense to me. If this is intended, then just put a mv A B && before either of the above commands and exchange A with B there.

Example with tar and gzip:

mv A B && tar cf - B | gzip -9 > B.tar.gz

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It depends on your version of tar

If you have the version that supports member transforms (--transform or --xform) then you can simply do

tar -c --transform=s/A/B/ A | gzip -9 > B.tar.gz

the | gzip -9 >B.tar.gz can be avoided if your tar supports the -z option

tar -zcvf B.tar.gz --transform=s/A/B/ A

If your version of tar doesn't support --transform then you will have to just copy the file first eg

 cp A B && tar -zcvf B.tar.gz B

However if you are only compressing one file why not skip the tar part all together and just do

cat A | gzip -9 > B.gz
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I've used cp as you did in your example but rename is mv –  Bob Vale Aug 5 '11 at 11:45
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