From 45e82a3a9c6b20fe3159b3dc2eb28d80a3b2ee67 Mon Sep 17 00:00:00 2001 From: Eugene Agafonov Date: Wed, 28 Mar 2018 15:42:34 +0300 Subject: 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} --- bytes.go | 105 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ bytes_test.go | 72 ++++++++++++++++++++++++++++++++++++++++ 2 files changed, 177 insertions(+) create mode 100644 bytes.go create mode 100644 bytes_test.go 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) +} diff --git a/bytes_test.go b/bytes_test.go new file mode 100644 index 0000000..cc4a769 --- /dev/null +++ b/bytes_test.go @@ -0,0 +1,72 @@ +package pflag + +import ( + "fmt" + "os" + "testing" +) + +func setUpBytesHex(bytesHex *[]byte) *FlagSet { + f := NewFlagSet("test", ContinueOnError) + f.BytesHexVar(bytesHex, "bytes", []byte{1, 2, 3, 4, 5, 6, 7, 8, 9, 0}, "Some bytes in HEX") + f.BytesHexVarP(bytesHex, "bytes2", "B", []byte{1, 2, 3, 4, 5, 6, 7, 8, 9, 0}, "Some bytes in HEX") + return f +} + +func TestBytesHex(t *testing.T) { + testCases := []struct { + input string + success bool + expected string + }{ + /// Positive cases + {"", true, ""}, // Is empty string OK ? + {"01", true, "01"}, + {"0101", true, "0101"}, + {"1234567890abcdef", true, "1234567890ABCDEF"}, + {"1234567890ABCDEF", true, "1234567890ABCDEF"}, + + // Negative cases + {"0", false, ""}, // Short string + {"000", false, ""}, /// Odd-length string + {"qq", false, ""}, /// non-hex character + } + + devnull, _ := os.Open(os.DevNull) + os.Stderr = devnull + + for i := range testCases { + var bytesHex []byte + f := setUpBytesHex(&bytesHex) + + tc := &testCases[i] + + // --bytes + args := []string{ + fmt.Sprintf("--bytes=%s", tc.input), + fmt.Sprintf("-B %s", tc.input), + fmt.Sprintf("--bytes2=%s", tc.input), + } + + for _, arg := range args { + err := f.Parse([]string{arg}) + + if err != nil && tc.success == true { + t.Errorf("expected success, got %q", err) + continue + } else if err == nil && tc.success == false { + // bytesHex, err := f.GetBytesHex("bytes") + t.Errorf("expected failure while processing %q", tc.input) + continue + } else if tc.success { + bytesHex, err := f.GetBytesHex("bytes") + if err != nil { + t.Errorf("Got error trying to fetch the IP flag: %v", err) + } + if fmt.Sprintf("%X", bytesHex) != tc.expected { + t.Errorf("expected %q, got '%X'", tc.expected, bytesHex) + } + } + } + } +} -- cgit v1.2.3