Sed - Extract help usage from comments

Makefile:

## help: print this help message
help:
	@echo 'Usage:'
	@sed -n 's/^##//p' ${MAKEFILE_LIST} | column -t -s ':' | sed -e 's/^/ /'

confirm:
	@echo -n 'Are you sure? [y/N] ' && read ans && [ $${ans:-N} = y ]

## run/api: run the cmd/api application
run/api:
	go run ./cmd/api

## db/psql: connect to the database using psql
db/psql:
	psql ${GREENLIGHT_DB_DSN}

## db/migrations/new name=$1: create a new database migration
db/migrations/new:
	@echo 'Creating migration files for ${name}...'
	migrate create -seq -ext=.sql -dir=./migrations ${name}

## db/migrations/up: apply all up database migrations
db/migrations/up: confirm
	@echo 'Running up migrations...'
	migrate -path ./migrations -database ${GREENLIGHT_DB_DSN} up

 

sed:

       -n, --quiet, --silent

              suppress automatic printing of pattern space

 

zzh@ZZHPC:~/zd/Github/ztest$ sed -n 's/^##//p' Makefile
 help: print this help message
 run/api: run the cmd/api application
 db/psql: connect to the database using psql
 db/migrations/new name=$1: create a new database migration
 db/migrations/up: apply all up database migrations

zzh@ZZHPC:~/zd/Github/ztest$ sed 's/^##//p' Makefile
 help: print this help message
 help: print this help message
help:
        @echo 'Usage:'
        @sed -n 's/^##//p' ${MAKEFILE_LIST} | column -t -s ':' | sed -e 's/^/ /'

confirm:
        @echo -n 'Are you sure? [y/N] ' && read ans && [ $${ans:-N} = y ]

 run/api: run the cmd/api application
 run/api: run the cmd/api application
run/api:
        go run ./cmd/api

 db/psql: connect to the database using psql
 db/psql: connect to the database using psql
db/psql:
        psql ${GREENLIGHT_DB_DSN}

 db/migrations/new name=$1: create a new database migration
 db/migrations/new name=$1: create a new database migration
db/migrations/new:
        @echo 'Creating migration files for ${name}...'
        migrate create -seq -ext=.sql -dir=./migrations ${name}

 db/migrations/up: apply all up database migrations
 db/migrations/up: apply all up database migrations
db/migrations/up: confirm
        @echo 'Running up migrations...'

 

zzh@ZZHPC:~/zd/Github/ztest$ sed 's/^##//' Makefile
 help: print this help message
help:
        @echo 'Usage:'
        @sed -n 's/^##//p' ${MAKEFILE_LIST} | column -t -s ':' | sed -e 's/^/ /'

confirm:
        @echo -n 'Are you sure? [y/N] ' && read ans && [ $${ans:-N} = y ]

 run/api: run the cmd/api application
run/api:
        go run ./cmd/api

 db/psql: connect to the database using psql
db/psql:
        psql ${GREENLIGHT_DB_DSN}

 db/migrations/new name=$1: create a new database migration
db/migrations/new:
        @echo 'Creating migration files for ${name}...'
        migrate create -seq -ext=.sql -dir=./migrations ${name}

 db/migrations/up: apply all up database migrations
db/migrations/up: confirm
        @echo 'Running up migrations...'
        migrate -path ./migrations -database ${GREENLIGHT_DB_DSN} up

 

zzh@ZZHPC:~/zd/Github/ztest$ sed -n 's/^##//p' Makefile
 help: print this help message
 run/api: run the cmd/api application
 db/psql: connect to the database using psql
 db/migrations/new name=$1: create a new database migration
 db/migrations/up: apply all up database migrations

zzh@ZZHPC:~/zd/Github/ztest$ sed -n 's/^##//p' Makefile | column -t -s ':'
 help                        print this help message
 run/api                     run the cmd/api application
 db/psql                     connect to the database using psql
 db/migrations/new name=$1   create a new database migration
 db/migrations/up            apply all up database migrations

 

Add two spaces at the beginning of each line:

zzh@ZZHPC:~/zd/Github/ztest$ sed -n 's/^##//p' Makefile | column -t -s ':' | sed -e 's/^/  /'
   help                        print this help message
   run/api                     run the cmd/api application
   db/psql                     connect to the database using psql
   db/migrations/new name=$1   create a new database migration
   db/migrations/up            apply all up database migrations