Add new FlagSet.Get{Int,String,...} accessor functions

If I declared a bool flag named "hello" I can now call

b, err := f.GetBool("hello")

And b will hold the value of the flag

We can see this is already done in
https://github.com/codegangsta/cli/blob/bcec9b08c7e5564f7512ad7e7b03778fe1923116/context.go
If people use the codegangsta/cli

Other projects have done it themselves using pflags (what inspired this
patch)
https://github.com/GoogleCloudPlatform/kubernetes/blob/cd817aebd848facda29e0befbbd6e31bf22402e6/pkg/kubectl/cmd/util/helpers.go#L176

Lets just do it ourselves...

1 files changed, 37 insertions, 1 deletions

diff --git a/ipmask.go b/ipmask.go
index 09b9533..1b10efb 100644
--- a/ipmask.go
+++ b/ipmask.go
@@ -3,6 +3,7 @@ package pflag
 import (
 	"fmt"
 	"net"
+	"strconv"
 )
 
 // -- net.IPMask value
@@ -32,11 +33,46 @@ func (i *ipMaskValue) Type() string {
 func ParseIPv4Mask(s string) net.IPMask {
 	mask := net.ParseIP(s)
 	if mask == nil {
-		return nil
+		if len(s) != 8 {
+			return nil
+		}
+		// net.IPMask.String() actually outputs things like ffffff00
+		// so write a horrible parser for that as well  :-(
+		m := []int{}
+		for i := 0; i < 4; i++ {
+			b := "0x" + s[2*i:2*i+2]
+			d, err := strconv.ParseInt(b, 0, 0)
+			if err != nil {
+				return nil
+			}
+			m = append(m, int(d))
+		}
+		s := fmt.Sprintf("%d.%d.%d.%d", m[0], m[1], m[2], m[3])
+		mask = net.ParseIP(s)
+		if mask == nil {
+			return nil
+		}
 	}
 	return net.IPv4Mask(mask[12], mask[13], mask[14], mask[15])
 }
 
+func parseIPv4Mask(sval string) (interface{}, error) {
+	mask := ParseIPv4Mask(sval)
+	if mask == nil {
+		return nil, fmt.Errorf("unable to parse %s as net.IPMask", sval)
+	}
+	return mask, nil
+}
+
+// GetIPv4Mask return the net.IPv4Mask value of a flag with the given name
+func (f *FlagSet) GetIPv4Mask(name string) (net.IPMask, error) {
+	val, err := f.getFlagType(name, "ipMask", parseIPv4Mask)
+	if err != nil {
+		return nil, err
+	}
+	return val.(net.IPMask), nil
+}
+
 // IPMaskVar defines an net.IPMask flag with specified name, default value, and usage string.
 // The argument p points to an net.IPMask variable in which to store the value of the flag.
 func (f *FlagSet) IPMaskVar(p *net.IPMask, name string, value net.IPMask, usage string) {