diff --git a/Makefile b/Makefile
index f8c6995..8add8d8 100644
--- a/Makefile
+++ b/Makefile
@@ -1,3 +1,20 @@
+
+# Copyright © 2022 Thomas von Dein
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+
 #
 # no need to modify anything below
 tool    = tablizer
diff --git a/cmd/parser.go b/cmd/parser.go
index 0b2d6f0..c27566d 100644
--- a/cmd/parser.go
+++ b/cmd/parser.go
@@ -1,3 +1,20 @@
+/*
+Copyright © 2022 Thomas von Dein
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
 package cmd
 
 import (
diff --git a/cmd/printer.go b/cmd/printer.go
index 337c1bd..c6e9c3e 100644
--- a/cmd/printer.go
+++ b/cmd/printer.go
@@ -1,3 +1,20 @@
+/*
+Copyright © 2022 Thomas von Dein
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
 package cmd
 
 import (
diff --git a/cmd/processinput.go b/cmd/processinput.go
new file mode 100644
index 0000000..4800f45
--- /dev/null
+++ b/cmd/processinput.go
@@ -0,0 +1,79 @@
+/*
+Copyright © 2022 Thomas von Dein
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package cmd
+
+import (
+	"errors"
+	"github.com/alecthomas/repr"
+	"os"
+	"strconv"
+	"strings"
+)
+
+func process(args []string) error {
+	var pattern string
+	havefiles := false
+
+	if len(Columns) > 0 {
+		for _, use := range strings.Split(Columns, ",") {
+			usenum, err := strconv.Atoi(use)
+			if err != nil {
+				die(err)
+			}
+			UseColumns = append(UseColumns, usenum)
+		}
+	}
+
+	if len(args) > 0 {
+		if _, err := os.Stat(args[0]); err != nil {
+			pattern = args[0]
+			args = args[1:]
+		}
+
+		if len(args) > 0 {
+			for _, file := range args {
+				fd, err := os.OpenFile(file, os.O_RDONLY, 0755)
+				if err != nil {
+					die(err)
+				}
+
+				data := parseFile(fd, pattern)
+				if Debug {
+					repr.Print(data)
+				}
+				printTable(data)
+			}
+			havefiles = true
+		}
+	}
+
+	if !havefiles {
+		stat, _ := os.Stdin.Stat()
+		if (stat.Mode() & os.ModeCharDevice) == 0 {
+			data := parseFile(os.Stdin, pattern)
+			if Debug {
+				repr.Print(data)
+			}
+			printTable(data)
+		} else {
+			return errors.New("No file specified and nothing to read on stdin!")
+		}
+	}
+
+	return nil
+}
diff --git a/cmd/root.go b/cmd/root.go
index 906103c..002441d 100644
--- a/cmd/root.go
+++ b/cmd/root.go
@@ -18,68 +18,23 @@ package cmd
 
 import (
 	"fmt"
-	"github.com/alecthomas/repr"
 	"github.com/spf13/cobra"
 	"os"
-	"strconv"
-	"strings"
 )
 
-var version = "v1.0.0"
+var version = "v1.0.1"
 
 var rootCmd = &cobra.Command{
 	Use:   "tablizer [regex] [file, ...]",
 	Short: "[Re-]tabularize tabular data",
 	Long:  `Manipulate tabular output of other programs`,
-	Run: func(cmd *cobra.Command, args []string) {
+	RunE: func(cmd *cobra.Command, args []string) error {
 		if Version {
 			fmt.Printf("This is tablizer version %s\n", version)
-			return
+			return nil
 		}
 
-		var pattern string
-		havefiles := false
-
-		if len(Columns) > 0 {
-			for _, use := range strings.Split(Columns, ",") {
-				usenum, err := strconv.Atoi(use)
-				if err != nil {
-					die(err)
-				}
-				UseColumns = append(UseColumns, usenum)
-			}
-		}
-
-		if len(args) > 0 {
-			if _, err := os.Stat(args[0]); err != nil {
-				pattern = args[0]
-				args = args[1:]
-			}
-
-			if len(args) > 0 {
-				for _, file := range args {
-					fd, err := os.OpenFile(file, os.O_RDONLY, 0755)
-					if err != nil {
-						die(err)
-					}
-
-					data := parseFile(fd, pattern)
-					if Debug {
-						repr.Print(data)
-					}
-					printTable(data)
-				}
-				havefiles = true
-			}
-		}
-
-		if !havefiles {
-			data := parseFile(os.Stdin, pattern)
-			if Debug {
-				repr.Print(data)
-			}
-			printTable(data)
-		}
+		return process(args)
 	},
 }
 
diff --git a/main.go b/main.go
index 53c565d..0562bcc 100644
--- a/main.go
+++ b/main.go
@@ -1,3 +1,20 @@
+/*
+Copyright © 2022 Thomas von Dein
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
 package main
 
 import (
diff --git a/mkrel.sh b/mkrel.sh
index 8f1d2cc..c93afa7 100755
--- a/mkrel.sh
+++ b/mkrel.sh
@@ -1,5 +1,21 @@
 #!/bin/bash
 
+# Copyright © 2022 Thomas von Dein
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+
 # get list with: go tool dist list
 DIST="darwin/amd64
 freebsd/amd64