Add multi-pipeline support to exec & lint (#568)

close #443

* add support to exec
* auto detect multi-pipeline for lint and exec
* de-duplicate code

cli/common/pipeline.go

@@ -0,0 +1,65 @@
+package common
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/urfave/cli/v2"
+)
+
+func DetectPipelineConfig() (multiplies bool, config string, _ error) {
+	config = ".woodpecker"
+	if fi, err := os.Stat(config); err == nil && fi.IsDir() {
+		return true, config, nil
+	}
+
+	config = ".woodpecker.yml"
+	if fi, err := os.Stat(config); err == nil && !fi.IsDir() {
+		return true, config, nil
+	}
+
+	config = ".drone.yml"
+	fi, err := os.Stat(config)
+	if err == nil && !fi.IsDir() {
+		return false, config, nil
+	}
+	return false, "", fmt.Errorf("could not detect pipeline config")
+}
+
+func RunPipelineFunc(c *cli.Context, fileFunc, dirFunc func(*cli.Context, string) error) error {
+	if c.Args().Len() == 0 {
+		isDir, path, err := DetectPipelineConfig()
+		if err != nil {
+			return err
+		}
+		if isDir {
+			return dirFunc(c, path)
+		}
+		return fileFunc(c, path)
+	}
+
+	multiArgs := c.Args().Len() > 1
+	for _, arg := range c.Args().Slice() {
+		fi, err := os.Stat(arg)
+		if err != nil {
+			return err
+		}
+		if multiArgs {
+			fmt.Println("#", fi.Name())
+		}
+		if fi.IsDir() {
+			if err := dirFunc(c, arg); err != nil {
+				return err
+			}
+		} else {
+			if err := fileFunc(c, arg); err != nil {
+				return err
+			}
+		}
+		if multiArgs {
+			fmt.Println("")
+		}
+	}
+
+	return nil
+}