A quick and easy way to check your .sh scripts against bugs within the current folder you are working on with Docker and ShellCheck. The command is a combination of:

• docker run -it koalaman/shellcheck-alpine /bin/sh: to run ShellCheck with /bin/sh in a Docker container
• --rm: to force Docker to remove the container when the main application finishes
• -v $(pwd):/docker-scripts: to mount the current directory in the folder docker-scripts of the container
• find /docker-scripts/ -type f -name '*.sh' | xargs shellcheck: to check all *.sh scripts with shellcheck

All put together:

docker run --rm -v $(pwd):/docker-scripts \
  -it koalaman/shellcheck-alpine \
  /bin/sh -c "find /docker-scripts/ -type f -name '*.sh' | xargs shellcheck"

Example of output:

In /docker-scripts/sort_json.sh line 4:
mydir=$1
^---^ SC2034: mydir appears unused. Verify use (or export if used externally).

With the reference SC2034, you can search for the issue in their wiki (SC2034).

References

• ShellCheck (GitHub)