Merge pull request #6147 from cyphar/6142-mflag-strip-quotes-long-equal-form

mflag: strip quotes in certain forms from flag values

pkg/mflag/flag.go

@@ -51,6 +51,8 @@
 	Command line flag syntax:
 		-flag
 		-flag=x
+		-flag="x"
+		-flag='x'
 		-flag x  // non-boolean flags only
 	One or two minus signs may be used; they are equivalent.
 	The last form is not permitted for boolean flags because the
@@ -775,6 +777,37 @@ func (f *FlagSet) usage() {
 	}
 }
 
+func trimQuotes(str string) string {
+	type quote struct {
+		start, end byte
+	}
+
+	// All valid quote types.
+	quotes := []quote{
+		// Double quotes
+		{
+			start: '"',
+			end:   '"',
+		},
+
+		// Single quotes
+		{
+			start: '\'',
+			end:   '\'',
+		},
+	}
+
+	for _, quote := range quotes {
+		// Only strip if outermost match.
+		if str[0] == quote.start && str[len(str)-1] == quote.end {
+			str = str[1 : len(str)-1]
+			break
+		}
+	}
+
+	return str
+}
+
 // parseOne parses one flag. It reports whether a flag was seen.
 func (f *FlagSet) parseOne() (bool, string, error) {
 	if len(f.args) == 0 {
@@ -799,7 +832,7 @@ func (f *FlagSet) parseOne() (bool, string, error) {
 	value := ""
 	for i := 1; i < len(name); i++ { // equals cannot be first
 		if name[i] == '=' {
-			value = name[i+1:]
+			value = trimQuotes(name[i+1:])
 			has_value = true
 			name = name[0:i]
 			break

pkg/mflag/flag_test.go

@@ -173,6 +173,12 @@ func testParse(f *FlagSet, t *testing.T) {
 	uintFlag := f.Uint([]string{"uint"}, 0, "uint value")
 	uint64Flag := f.Uint64([]string{"-uint64"}, 0, "uint64 value")
 	stringFlag := f.String([]string{"string"}, "0", "string value")
+	singleQuoteFlag := f.String([]string{"squote"}, "", "single quoted value")
+	doubleQuoteFlag := f.String([]string{"dquote"}, "", "double quoted value")
+	mixedQuoteFlag := f.String([]string{"mquote"}, "", "mixed quoted value")
+	mixed2QuoteFlag := f.String([]string{"mquote2"}, "", "mixed2 quoted value")
+	nestedQuoteFlag := f.String([]string{"nquote"}, "", "nested quoted value")
+	nested2QuoteFlag := f.String([]string{"nquote2"}, "", "nested2 quoted value")
 	float64Flag := f.Float64([]string{"float64"}, 0, "float64 value")
 	durationFlag := f.Duration([]string{"duration"}, 5*time.Second, "time.Duration value")
 	extra := "one-extra-argument"
@@ -184,6 +190,12 @@ func testParse(f *FlagSet, t *testing.T) {
 		"-uint", "24",
 		"--uint64", "25",
 		"-string", "hello",
+		"-squote='single'",
+		`-dquote="double"`,
+		`-mquote='mixed"`,
+		`-mquote2="mixed2'`,
+		`-nquote="'single nested'"`,
+		`-nquote2='"double nested"'`,
 		"-float64", "2718e28",
 		"-duration", "2m",
 		extra,
@@ -215,6 +227,24 @@ func testParse(f *FlagSet, t *testing.T) {
 	if *stringFlag != "hello" {
 		t.Error("string flag should be `hello`, is ", *stringFlag)
 	}
+	if *singleQuoteFlag != "single" {
+		t.Error("single quote string flag should be `single`, is ", *singleQuoteFlag)
+	}
+	if *doubleQuoteFlag != "double" {
+		t.Error("double quote string flag should be `double`, is ", *doubleQuoteFlag)
+	}
+	if *mixedQuoteFlag != `'mixed"` {
+		t.Error("mixed quote string flag should be `'mixed\"`, is ", *mixedQuoteFlag)
+	}
+	if *mixed2QuoteFlag != `"mixed2'` {
+		t.Error("mixed2 quote string flag should be `\"mixed2'`, is ", *mixed2QuoteFlag)
+	}
+	if *nestedQuoteFlag != "'single nested'" {
+		t.Error("nested quote string flag should be `'single nested'`, is ", *nestedQuoteFlag)
+	}
+	if *nested2QuoteFlag != `"double nested"` {
+		t.Error("double quote string flag should be `\"double nested\"`, is ", *nested2QuoteFlag)
+	}
 	if *float64Flag != 2718e28 {
 		t.Error("float64 flag should be 2718e28, is ", *float64Flag)
 	}