What is the `<<-EOSQL` code block in Bash when running SQL?
EOSQL
is a limit string for a Bash Here Document block. It signifies the start and end of a text block to the bash interpreter. The limit string can be any text that doesn't appear in your block.
Variable substitution will work as normal in a here document:
#!/usr/bin/env bashcat <<-EOF$MY_EXTENSIONEOF
Then running that with the variable set:
$ MY_EXTENSION=something ./test.shsomething
In Docker you will need ENV MY_EXTENSION=something
in your Dockerfile
or docker run -e MY_EXTENSION=something <image>
on your command line for the environment to be setup.