examples: review, testing and documentation (#176)

* examples reviews, testing and documentation

* including the execution on travis, and fix readme

* fix example link

* including the execution on travis

1 files changed, 32 insertions, 0 deletions

diff --git a/examples/common.go b/examples/common.go
new file mode 100644
index 0000000..971b0f6
--- /dev/null
+++ b/examples/common.go
@@ -0,0 +1,32 @@
+package examples
+
+import (
+	"os"
+	"strings"
+
+	"github.com/fatih/color"
+)
+
+func CheckArgs(arg ...string) {
+	if len(os.Args) < len(arg)+1 {
+		Warning("Usage: %s %s", os.Args[0], strings.Join(arg, " "))
+		os.Exit(1)
+	}
+}
+
+func CheckIfError(err error) {
+	if err == nil {
+		return
+	}
+
+	color.Red("error: %s", err)
+	os.Exit(1)
+}
+
+func Info(format string, args ...interface{}) {
+	color.Blue(format, args...)
+}
+
+func Warning(format string, args ...interface{}) {
+	color.Cyan(format, args...)
+}