Include proper version string

Makefile

@@ -1,16 +1,21 @@
 GITREV  ?= $(shell git describe --dirty --always)
 BLDDATE ?= $(shell date -I)
 CR_YEAR ?= $(shell date +%Y)
+VERSION ?= "v0.1.2"
 
 CFLAGS ?= -Wall -Wextra -Wpedantic -O2 -std=gnu99
 CFLAGS += -DGITREV='"$(GITREV)"'
 CFLAGS += -DBLDDATE='"$(BLDDATE)"'
 CFLAGS += -DCR_YEAR='"$(CR_YEAR)"'
+CFLAGS += -DVERSION='$(VERSION)'
 
 # Soon...
 # CFLAGS += $(shell pkg-config --cflags libudev)
 # LIBS   += $(shell pkg-config --libs libudev)
 
+PREFIX ?= /usr/local
+DESTDIR ?=
+
 writeimg: writeimg.c
 	$(CC) $(CFLAGS) $(LIBS) -o $@ $^
 
@@ -18,4 +23,4 @@ clean:
 	rm -f *.o writeimg
 
 install: writeimg
-	install -m 0755 writeimg /usr/local/bin/writeimg
+	install -m 0755 $< $(DESTDIR)$(PREFIX)/bin/$<

writeimg.c

@@ -10,10 +10,12 @@
 #include <sys/stat.h>
 #include <unistd.h>
 
-#ifdef GITREV
+#ifndef GITREV
-#define VERSION GITREV
+#define GITREV "unknown"
-#else
+#endif
-#define VERSION "1.0.0"
+
+#ifndef VERSION
+#define VERSION "unknown"
 #endif
 
 #ifndef CR_YEAR
@@ -127,11 +129,11 @@ static const struct option longopts[] = {
 };
 
 int main(int argc, char *argv[]) {
-    printf("%s version %s\n", basename(argv[0]), VERSION);
+    printf("%s %s, Rev. %s\n", basename(argv[0]), VERSION, GITREV);
+    fprintf(stdout, copyright, CR_YEAR);
 #ifdef BLDDATE
     printf("Build date: %s\n", BLDDATE);
 #endif
-    fprintf(stdout, copyright, CR_YEAR);
     printf("\n");
 
     /* Line buffering, system allocated */