warn when there are no files to decrypt

config.go

@@ -253,7 +253,7 @@ func parseCli(args []string) (options, []string, error) {
 	NoEncrypt := pflag.Bool("no-encrypt", false, "do not encrypt the dumps")
 	pflag.BoolVar(&opts.EncryptKeepSrc, "encrypt-keep-src", false, "keep original files when encrypting")
 	NoEncryptKeepSrc := pflag.Bool("no-encrypt-keep-src", false, "do not keep original files when encrypting")
-	pflag.BoolVar(&opts.Decrypt, "decrypt", false, "decrypt files in the backup directory")
+	pflag.BoolVar(&opts.Decrypt, "decrypt", false, "decrypt files in the backup directory instead of dumping. DBNAMEs become\nglobs to select files")
 	pflag.StringVar(&opts.CipherPassphrase, "cipher-pass", "", "cipher passphrase for encryption and decryption\n")
 
 	pflag.StringVar(&opts.Upload, "upload", "none", "upload produced files to target (s3, gcs,..) use \"none\" to override\nconfiguration file and disable upload")

main.go

@@ -901,7 +901,7 @@ func decryptDirectory(dir string, password string, workers int, globs []string)
 	// return an error
 	ret := make(chan bool, workers)
 
-	// Start workers than listen for filenames to decrypt until the queue
+	// Start workers that listen for filenames to decrypt until the queue
 	// is closed
 	for i := 0; i < workers; i++ {
 		wg.Add(1)
@@ -938,6 +938,7 @@ func decryptDirectory(dir string, password string, workers int, globs []string)
 		return fmt.Errorf("unable to read directory %s: %w", dir, err)
 	}
 
+	var c int
 	for _, path := range entries {
 		keep := true
 		if len(globs) > 0 {
@@ -976,6 +977,7 @@ func decryptDirectory(dir string, password string, workers int, globs []string)
 
 				file := filepath.Join(subdir, subpath.Name())
 				if strings.HasSuffix(file, ".age") {
+					c++
 					fq <- file
 				}
 			}
@@ -984,10 +986,16 @@ func decryptDirectory(dir string, password string, workers int, globs []string)
 
 		file := filepath.Join(dir, path.Name())
 		if strings.HasSuffix(file, ".age") {
+			c++
 			fq <- file
 		}
 	}
 
+	// Print a warning when no candidate files are found with a hint that the dbname is a glob
+	if c == 0 {
+		l.Warnln("no candidate file found for decryption. Maybe add a wildcard (*) to the patterns?")
+	}
+
 	// Closing the channel will make the workers stop as soon as it is
 	// empty
 	close(fq)