added resolver for version flag and also added help section for makef…

…ile, version and build date injection

Makefile

@@ -1,3 +1,9 @@
+BIN := $(shell basename $$PWD)
+HASH := $(shell git rev-parse HEAD | cut -c 1-8)
+COMMIT_DATE := $(shell git show -s --format=%ci ${HASH})
+BUILD_DATE := $(shell date '+%Y-%m-%d %H:%M:%S')
+VERSION := ${HASH} (${COMMIT_DATE})
+
 STATIC := config.toml.sample schema.sql queries.sql
 
 # Install dependencies needed for building
@@ -7,7 +13,7 @@ deps:
 
 .PHONY: build
 build:
-	go build -o dictmaker
+	go build -o ${BIN} -ldflags="-X 'main.buildVersion=${VERSION}' -X 'main.buildDate=${BUILD_DATE}'"
 	stuffbin -a stuff -in dictmaker -out dictmaker ${STATIC}
 
 .PHONY: build-tokenizers
@@ -21,3 +27,10 @@ build-tokenizers:
 .PHONY: pack-releases
 pack-releases:
 	$(foreach var,$(RELEASE_BUILDS),stuffbin -a stuff -in ${var} -out ${var} ${STATIC} $(var);)
+
+# Absolutely awesome: http://marmelab.com/blog/2016/02/29/auto-documented-makefile.html
+.PHONY: help
+help:
+	@grep -E '^[a-zA-Z_-]+:.*?## .*$$' $(MAKEFILE_LIST) | awk 'BEGIN {FS = ":.*?## "}; {printf "\033[36m%-30s\033[0m %s\n", $$1, $$2}'
+
+.DEFAULT_GOAL := build

main.go

@@ -21,6 +21,11 @@ import (
 	flag "github.com/spf13/pflag"
 )
 
+var (
+	buildVersion = "unknown"
+	buildDate    = "unknown"
+)
+
 // Lang represents a language's configuration.
 type Lang struct {
 	Name          string            `koanf:"name"`
@@ -96,6 +101,11 @@ func init() {
 	if err := ko.Load(posflag.Provider(f, ".", ko), nil); err != nil {
 		logger.Fatalf("error loading config: %v", err)
 	}
+
+	if ko.Bool("version") {
+		fmt.Printf("Commit: %v\nBuild: %v\n", buildVersion, buildDate)
+		os.Exit(0)
+	}
 }
 
 func main() {