How do you get the list of targets in a makefile?

Question

I\'ve used rake a bit (a Ruby make program), and it has an option to get a list of all the available targets, eg

> rake --tasks
rake db:charset      # ret         


        

Answer 1

Focusing on an easy syntax for describing a make target, and having a clean output, I chose this approach:

help:
    @grep -B1 -E "^[a-zA-Z0-9_-]+\:([^\=]|$$)" Makefile \
     | grep -v -- -- \
     | sed 'N;s/\n/###/' \
     | sed -n 's/^#: \(.*\)###\(.*\):.*/\2###\1/p' \
     | column -t  -s '###'


#: Starts the container stack
up: a b
  command

#: Pulls in new container images
pull: c d 
    another command

make-target-not-shown:

# this does not count as a description, so leaving
# your implementation comments alone, e.g TODOs
also-not-shown:

So treating the above as a Makefile and running it gives you something like

> make help
up          Starts the container stack
pull        Pulls in new container images

Explanation for the chain of commands:

• First, grep all targets and their preceeding line, see https://unix.stackexchange.com/a/320709/223029.
• Then, get rid of the group separator, see https://stackoverflow.com/a/2168139/1242922.
• Then, we collapse each pair of lines to parse it later, see https://stackoverflow.com/a/9605559/1242922.
• Then, we parse for valid lines and remove those which do not match, see https://stackoverflow.com/a/8255627/1242922, and also give the output our desired order: command, then description.
• Lastly, we arrange the output like a table.