program works now, added a little documentation

printer.go

@@ -0,0 +1,81 @@
+package main
+
+import (
+	"fmt"
+	"io"
+	"sort"
+)
+
+func ListTemplates(output io.Writer) {
+	names := []string{}
+
+	for name := range Templates {
+		names = append(names, name)
+	}
+
+	sort.Strings(names)
+
+	for _, name := range names {
+		fmt.Fprintln(output, name)
+	}
+}
+
+func PrintColumns(names []string, output io.Writer) error {
+	count := len(names)
+
+	// no need for the hassle to calculate columns
+	if count <= Columns {
+		for _, name := range names {
+			fmt.Fprintln(output, name)
+		}
+
+		return nil
+	}
+
+	// get a transposed list of columns
+	padlist, max := Getcolumns(names, Columns)
+
+	// make sure there's enough spacing between the columns
+	format := fmt.Sprintf("%%-%ds", max+1)
+
+	for _, row := range padlist {
+		for _, word := range row {
+			fmt.Fprintf(output, format, word)
+		}
+		fmt.Fprintln(output)
+	}
+
+	return nil
+}
+
+func Getcolumns(names []string, columns int) ([][]string, int) {
+	words := len(names)
+	max := 0
+
+	// we'll have a list of $columns columns
+	padlist := make([][]string, columns)
+
+	// initialize'em
+	for col := 0; col < columns; col++ {
+		padlist[col] = []string{}
+	}
+
+	// fill from input
+	for idx := 0; idx < words; idx += columns {
+		for col := 0; col < columns; col++ {
+			if idx+col >= words {
+				padlist[col] = append(padlist[col], "")
+			} else {
+				padlist[col] = append(padlist[col], names[idx+col])
+				length := len(names[idx+col])
+				if length > max {
+					max = length
+				}
+			}
+
+		}
+	}
+
+	// turn columns to rows
+	return Transpose(padlist), max
+}