Merge branch 'add_version_flag' of asdf/gfu into master

README.md

@@ -21,7 +21,7 @@ Assuming you have `go` installed, run the following:
 ```
 git clone https://tildegit.org/sloum/gfu.git
 cd gfu
-go install
+make install
 ```
 Assuming `go install` is set up to install to a place on your path, you should be able to execute `gfu` from the terminal:
 ```
@@ -29,7 +29,7 @@ gfu
 ```
 
 #### Troubleshooting
-If you run `gfu` and get `gfu: command not found`, try running `go build` from within the cloned repo. Then try: `./gfu`. If that works it means that Go does not install to your path. `go build` added an executable file to the repo directory. Move that file to somewhere on your path. I suggest `/usr/local/bin` on most systems, but that may be a matter of personal preference.
+If you run `gfu` and get `gfu: command not found`, try running `make` from within the cloned repo. Then try: `./gfu`. If that works it means that Go does not install to your path. `make` added an executable file to the repo directory. Move that file to somewhere on your path. I suggest `/usr/local/bin` on most systems, but that may be a matter of personal preference.
 
 ### Downloading
 If you would prefer to download a binary for your system, rather than build from source, please visit the [gfu downloads](https://rawtext.club/~sloum/gfu.html#downloads) page.

VERSION

@@ -0,0 +1 @@
+0.1

main.go

@@ -42,12 +42,19 @@ import (
 	"strings"
 )
 
+//version information, set by ldflags with some default fallbacks
+var (
+	version string = "not set"
+	build   string = "not set"
+)
+
 //command line flag global variables
 var (
 	deconstructInfoTextLines bool
 	header                   string
 	footer                   string
 	stdout                   bool
+	printVersion             bool
 )
 
 //regex global variable that identifies the format of gopher menu lines
@@ -142,6 +149,7 @@ func init() {
 	flag.StringVar(&header, "head", "", "Path to a file containing header content")
 	flag.StringVar(&footer, "foot", "", "Path to a file containing footer content")
 	flag.BoolVar(&stdout, "stdout", false, "Instead of writing changes to a file, return them to stdout")
+	flag.BoolVar(&printVersion, "v", false, "Output version information")
 }
 
 //PrintHelp produces a nice display message when the --help flag is used
@@ -165,6 +173,10 @@ func main() {
 	flag.Parse()
 	args := flag.Args()
 
+	if printVersion {
+		fmt.Printf("gfu - gophermap format utility - version %s build %s\n", version, build)
+		os.Exit(0)
+	}
 	if l := len(args); l != 1 {
 		fmt.Fprintf(os.Stderr, "Incorrect number of arguments. Expected 1, got %d\n", l)
 		os.Exit(1)

makefile

@@ -0,0 +1,29 @@
+BINARY	:= gfu
+PKGS	:= $(shell go list ./... |grep -v /vendor)
+
+# version checks git tags. if any errors, they are discarded, and the version is
+# read from the VERSION file
+VERSION	:= $(shell git describe --tags 2> /dev/null)
+ifeq ($(VERSION),)	
+	VERSION := $(shell cat VERSION)
+endif
+BUILD		:= $(shell date -Iminutes)
+
+#ldflags for versioning info: https://stackoverflow.com/questions/11354518/application-auto-build-versioning
+#-s flag info: https://blog.spiralscout.com/using-w-and-s-flags-in-golang-97ae59b50e26
+LDFLAGS	:= -ldflags "-s -X main.version=${VERSION} -X main.build=${BUILD}"
+
+build:
+	go build ${LDFLAGS} -o ${BINARY}
+
+.PHONY: install
+install:
+	go install ${LDFLAGS}
+
+.PHONY: uninstall
+uninstall:
+	go clean -i
+
+.PHONY: clean
+clean:
+	go clean