Updated on April 18th, 2023 in #linux

Create Parent Directories with Curl Using the --create-dirs Flag

This can save you from writing a file to a temporary directory and then moving it after using mkdir.

Quick Jump: Demo Video

Let’s say you want to download a file to a specific directory that doesn’t exist yet and also make it executable. I do this a lot with curl.

Not using --create-dirs:

curl https://raw.githubusercontent.com/nickjj/notes/master/notes \
  --output /tmp/notes \
  && chmod +x /tmp/notes \
  && mkdir -p /tmp/custom/dir/path \
  && mv /tmp/notes /tmp/custom/dir/path

Using --create-dirs:

curl https://raw.githubusercontent.com/nickjj/notes/master/notes \
  --create-dirs --output /tmp/custom/dir/path/notes \
  && chmod +x /tmp/custom/dir/path/notes

Since the last argument of the above command is the path of the file we can even improve on that by using $_ which contains the last argument of the previous command.

This way we can avoid duplicating the path without creating a custom variable:

curl https://raw.githubusercontent.com/nickjj/notes/master/notes \
  --create-dirs --output /tmp/custom/dir/path/notes \
  && chmod +x "${_}"

If any of the directories exist then they won’t be created but the command will still work. The directories get created with 0750 permissions.

--create-dirs has been available since curl 7.10.3 (January 2003).

Demo Video

Timestamps

• 0:32 – Saving a file with curl
• 1:15 – Saving a file to a directory that doesn’t exist, the hard way
• 2:46 – Simplifying things with the –create-dirs flag
• 3:39 – Using the shell to our advantage to make it better
• 4:46 – If the directories exist, curl is smart enough to still work
• 5:08 – This flag has been around for 20+ years

References

• https://github.com/nickjj/notes
• https://nickjanetakis.com/blog/why-you-should-put-braces-around-your-variables-when-shell-scripting

When did you learn about this flag? Let me know below!