There are many different ways to accomplish extracting a tarball from the internet.
In my case I wanted to extract helm binary from it's original tarball release.
I'm using tar 1.30 and wget 1.20.1 to do this.
First, do a test extraction to see what the file structure of the tarball looks like:
wget -qO- https://get.helm.sh/helm-v3.4.2-linux-amd64.tar.gz | tar tvfz -
drwxr-xr-x circleci/circleci 0 2020-12-09 10:21 linux-amd64/
-rwxr-xr-x circleci/circleci 41603072 2020-12-09 10:20 linux-amd64/helm
-rw-r--r-- circleci/circleci 3341 2020-12-09 10:21 linux-amd64/README.md
-rw-r--r-- circleci/circleci 11373 2020-12-09 10:21 linux-amd64/LICENSE
Using --wildcards and --transform will allow you to only extract out the helm executable without the linux-amd64 folder.
After you find the target file you want to extract you can extract it via:
wget -qO- https://get.helm.sh/helm-v3.4.2-linux-amd64.tar.gz | \
tar xvzf - -C /tmp/ --wildcards *helm --transform 's/^linux-amd64\///'
And you'll be left with:
ls -ld /tmp/helm
-rwxr-xr-x 1 silas silas 41603072 Dec 9 10:20 /tmp/helm