Single command to create a file and set its permission

Question

I am using the following 2 commands to create a 0B file and set its extn to 644

touch filename.ext
chmod 777 filename.txt

My question is that w

Answer 1

Because of Docker and Alpine, I imagine there are a lot of people interested in creating executable one-liners without the help of bash-isms. It's pretty simple with install

$ docker build -t temp - < d6e46aa2470d
Step 2/3 : RUN echo "date" | install -m 775 /dev/stdin /bin/now
 ---> Running in 95919b575638
Removing intermediate container 95919b575638
 ---> cd1fafd96ef3
Step 3/3 : CMD /bin/now
 ---> Running in 03b5c3ac7265
Removing intermediate container 03b5c3ac7265
 ---> 8f30b527dd29
Successfully built 8f30b527dd29
Successfully tagged temp:latest

$ docker run --rm temp
Thu Nov 12 07:44:24 UTC 2020

$ docker run --rm temp ls -la /bin/now
-rwxrwxr-x    1 root     root             5 Nov 12 07:44 /bin/now

$ docker rmi temp
Untagged: temp:latest
Deleted: sha256:8f30b527dd29203b67c86290b34b0a29d3c98a48134609d0b1e2b89087a7d6e7
Deleted: sha256:cd1fafd96ef3084226c5f98f472e3e08bc9a9f0448cc3e68b6f1c192d12d778a
Deleted: sha256:e58c75acbf953a64d35089cf50e1c5b762601e1cb9d9d1d668e135f23ce1fe86