add the --download-ncbi option to obitaxonomy

pkg/obiutils/download.go

@@ -0,0 +1,45 @@
+package obiutils
+
+import (
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+
+	"github.com/schollz/progressbar/v3"
+)
+
+func DownloadFile(url string, filepath string) error {
+	// Get the data
+	resp, err := http.Get(url)
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+
+	// Check server response
+	if resp.StatusCode != http.StatusOK {
+		return fmt.Errorf("bad status: %s", resp.Status)
+	}
+
+	// Create the file
+	out, err := os.Create(filepath)
+	if err != nil {
+		return err
+	}
+	defer out.Close()
+
+	// Create progress bar
+	bar := progressbar.DefaultBytes(
+		resp.ContentLength,
+		"downloading",
+	)
+
+	// Write the body to file while updating the progress bar
+	_, err = io.Copy(io.MultiWriter(out, bar), resp.Body)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}