Implement BytesHex type of argument (#115)

BytesHex is an []byte represented as HEX-string

--bytes=010203040506070809 states for []bytes{1,2,3,4,5,6,7,8,9}

1 files changed, 105 insertions, 0 deletions

diff --git a/bytes.go b/bytes.go
new file mode 100644
index 0000000..12c58db
--- /dev/null
+++ b/bytes.go
@@ -0,0 +1,105 @@
+package pflag
+
+import (
+	"encoding/hex"
+	"fmt"
+	"strings"
+)
+
+// BytesHex adapts []byte for use as a flag. Value of flag is HEX encoded
+type bytesHexValue []byte
+
+func (bytesHex bytesHexValue) String() string {
+	return fmt.Sprintf("%X", []byte(bytesHex))
+}
+
+func (bytesHex *bytesHexValue) Set(value string) error {
+	bin, err := hex.DecodeString(strings.TrimSpace(value))
+
+	if err != nil {
+		return err
+	}
+
+	*bytesHex = bin
+
+	return nil
+}
+
+func (*bytesHexValue) Type() string {
+	return "bytesHex"
+}
+
+func newBytesHexValue(val []byte, p *[]byte) *bytesHexValue {
+	*p = val
+	return (*bytesHexValue)(p)
+}
+
+func bytesHexConv(sval string) (interface{}, error) {
+
+	bin, err := hex.DecodeString(sval)
+
+	if err == nil {
+		return bin, nil
+	}
+
+	return nil, fmt.Errorf("invalid string being converted to Bytes: %s %s", sval, err)
+}
+
+// GetBytesHex return the []byte value of a flag with the given name
+func (f *FlagSet) GetBytesHex(name string) ([]byte, error) {
+	val, err := f.getFlagType(name, "bytesHex", bytesHexConv)
+
+	if err != nil {
+		return []byte{}, err
+	}
+
+	return val.([]byte), nil
+}
+
+// BytesHexVar defines an []byte flag with specified name, default value, and usage string.
+// The argument p points to an []byte variable in which to store the value of the flag.
+func (f *FlagSet) BytesHexVar(p *[]byte, name string, value []byte, usage string) {
+	f.VarP(newBytesHexValue(value, p), name, "", usage)
+}
+
+// BytesHexVarP is like BytesHexVar, but accepts a shorthand letter that can be used after a single dash.
+func (f *FlagSet) BytesHexVarP(p *[]byte, name, shorthand string, value []byte, usage string) {
+	f.VarP(newBytesHexValue(value, p), name, shorthand, usage)
+}
+
+// BytesHexVar defines an []byte flag with specified name, default value, and usage string.
+// The argument p points to an []byte variable in which to store the value of the flag.
+func BytesHexVar(p *[]byte, name string, value []byte, usage string) {
+	CommandLine.VarP(newBytesHexValue(value, p), name, "", usage)
+}
+
+// BytesHexVarP is like BytesHexVar, but accepts a shorthand letter that can be used after a single dash.
+func BytesHexVarP(p *[]byte, name, shorthand string, value []byte, usage string) {
+	CommandLine.VarP(newBytesHexValue(value, p), name, shorthand, usage)
+}
+
+// BytesHex defines an []byte flag with specified name, default value, and usage string.
+// The return value is the address of an []byte variable that stores the value of the flag.
+func (f *FlagSet) BytesHex(name string, value []byte, usage string) *[]byte {
+	p := new([]byte)
+	f.BytesHexVarP(p, name, "", value, usage)
+	return p
+}
+
+// BytesHexP is like BytesHex, but accepts a shorthand letter that can be used after a single dash.
+func (f *FlagSet) BytesHexP(name, shorthand string, value []byte, usage string) *[]byte {
+	p := new([]byte)
+	f.BytesHexVarP(p, name, shorthand, value, usage)
+	return p
+}
+
+// BytesHex defines an []byte flag with specified name, default value, and usage string.
+// The return value is the address of an []byte variable that stores the value of the flag.
+func BytesHex(name string, value []byte, usage string) *[]byte {
+	return CommandLine.BytesHexP(name, "", value, usage)
+}
+
+// BytesHexP is like BytesHex, but accepts a shorthand letter that can be used after a single dash.
+func BytesHexP(name, shorthand string, value []byte, usage string) *[]byte {
+	return CommandLine.BytesHexP(name, shorthand, value, usage)
+}