Howto pipe: cp | tar | gzip without creating intermediary files?

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

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