fix: coop-cloud -> toolshed

Bumps [actions/setup-go](https://github.com/actions/setup-go) from 3 to 4.
- [Release notes](https://github.com/actions/setup-go/releases)
- [Commits](https://github.com/actions/setup-go/compare/v3...v4)

---
updated-dependencies:
- dependency-name: actions/setup-go
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/ci.yml

@@ -14,7 +14,7 @@ jobs:
     steps:
       - uses: actions/checkout@v3
       - name: Setup go
-        uses: actions/setup-go@v3
+        uses: actions/setup-go@v4
         with:
           go-version: ${{ matrix.go }}
       - run: go test

README.md

@@ -153,6 +153,8 @@ godotenv -f /some/path/to/.env some_command with some args
 
 If you don't specify `-f` it will fall back on the default of loading `.env` in `PWD`
 
+By default, it won't override existing environment variables; you can do that with the `-o` flag.
+
 ### Writing Env Files
 
 Godotenv can also write a map representing the environment to a correctly-formatted and escaped file

autoload/autoload.go

@@ -8,7 +8,7 @@ package autoload
 	And bob's your mother's brother
 */
 
-import "github.com/joho/godotenv"
+import "git.coopcloud.tech/toolshed/godotenv"
 
 func init() {
 	godotenv.Load()

cmd/godotenv/cmd.go

@@ -7,7 +7,7 @@ import (
 
 	"strings"
 
-	"github.com/joho/godotenv"
+	"git.coopcloud.tech/toolshed/godotenv"
 )
 
 func main() {
@@ -15,13 +15,15 @@ func main() {
 	flag.BoolVar(&showHelp, "h", false, "show help")
 	var rawEnvFilenames string
 	flag.StringVar(&rawEnvFilenames, "f", "", "comma separated paths to .env files")
+	var overload bool
+	flag.BoolVar(&overload, "o", false, "override existing .env variables")
 
 	flag.Parse()
 
 	usage := `
 Run a process with an env setup from a .env file
 
-godotenv [-f ENV_FILE_PATHS] COMMAND_ARGS
+godotenv [-o] [-f ENV_FILE_PATHS] COMMAND_ARGS
 
 ENV_FILE_PATHS: comma separated paths to .env files
 COMMAND_ARGS: command and args you want to run
@@ -47,7 +49,7 @@ example
 	cmd := args[0]
 	cmdArgs := args[1:]
 
-	err := godotenv.Exec(envFilenames, cmd, cmdArgs)
+	err := godotenv.Exec(envFilenames, cmd, cmdArgs, overload)
 	if err != nil {
 		log.Fatal(err)
 	}

fixtures/plain.env

@@ -5,3 +5,4 @@ OPTION_D =4
 OPTION_E = 5
 OPTION_F = 
 OPTION_G=
+OPTION_H=1 2

go.mod

@@ -1,3 +1,3 @@
-module github.com/joho/godotenv
+module git.coopcloud.tech/toolshed/godotenv
 
 go 1.12

godotenv.go

@@ -4,23 +4,21 @@
 //
 // The TL;DR is that you make a .env file that looks something like
 //
-// 		SOME_ENV_VAR=somevalue
+//	SOME_ENV_VAR=somevalue
 //
 // and then in your go code you can call
 //
-// 		godotenv.Load()
+//	godotenv.Load()
 //
 // and all the env vars declared in .env will be available through os.Getenv("SOME_ENV_VAR")
 package godotenv
 
 import (
-	"errors"
+	"bytes"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"os"
 	"os/exec"
-	"regexp"
 	"sort"
 	"strconv"
 	"strings"
@@ -29,13 +27,14 @@ import (
 const doubleQuoteSpecialChars = "\\\n\r\"!$`"
 
 // Parse reads an env file from io.Reader, returning a map of keys and values.
-func Parse(r io.Reader) (map[string]string, error) {
-	data, err := ioutil.ReadAll(r)
+func Parse(r io.Reader) (map[string]string, map[string]map[string]string, error) {
+	var buf bytes.Buffer
+	_, err := io.Copy(&buf, r)
 	if err != nil {
-		return nil, err
+		return nil, nil, err
 	}
 
-	return UnmarshalBytes(data)
+	return UnmarshalBytes(buf.Bytes())
 }
 
 // Load will read your env file(s) and load them into ENV for this process.
@@ -46,7 +45,7 @@ func Parse(r io.Reader) (map[string]string, error) {
 //
 // You can otherwise tell it which files to load (there can be more than one) like:
 //
-//		godotenv.Load("fileone", "filetwo")
+//	godotenv.Load("fileone", "filetwo")
 //
 // It's important to note that it WILL NOT OVERRIDE an env variable that already exists - consider the .env file to set dev vars or sensible defaults.
 func Load(filenames ...string) (err error) {
@@ -69,7 +68,7 @@ func Load(filenames ...string) (err error) {
 //
 // You can otherwise tell it which files to load (there can be more than one) like:
 //
-//		godotenv.Overload("fileone", "filetwo")
+//	godotenv.Overload("fileone", "filetwo")
 //
 // It's important to note this WILL OVERRIDE an env variable that already exists - consider the .env file to forcefully set all vars.
 func Overload(filenames ...string) (err error) {
@@ -86,12 +85,13 @@ func Overload(filenames ...string) (err error) {
 
 // Read all env (with same file loading semantics as Load) but return values as
 // a map rather than automatically writing values into env
-func Read(filenames ...string) (envMap map[string]string, err error) {
+func Read(filenames ...string) (envMap map[string]string, modMap map[string]map[string]string, err error) {
 	filenames = filenamesOrDefault(filenames)
 	envMap = make(map[string]string)
+	modMap = make(map[string]map[string]string)
 
 	for _, filename := range filenames {
-		individualEnvMap, individualErr := readFile(filename)
+		individualEnvMap, individualModMap, individualErr := readFile(filename)
 
 		if individualErr != nil {
 			err = individualErr
@@ -101,22 +101,27 @@ func Read(filenames ...string) (envMap map[string]string, err error) {
 		for key, value := range individualEnvMap {
 			envMap[key] = value
 		}
+
+		for key, value := range individualModMap {
+			modMap[key] = value
+		}
 	}
 
 	return
 }
 
 // Unmarshal reads an env file from a string, returning a map of keys and values.
-func Unmarshal(str string) (envMap map[string]string, err error) {
+func Unmarshal(str string) (envMap map[string]string, modifierMap map[string]map[string]string, err error) {
 	return UnmarshalBytes([]byte(str))
 }
 
 // UnmarshalBytes parses env file from byte slice of chars, returning a map of keys and values.
-func UnmarshalBytes(src []byte) (map[string]string, error) {
-	out := make(map[string]string)
-	err := parseBytes(src, out)
+func UnmarshalBytes(src []byte) (map[string]string, map[string]map[string]string, error) {
+	vars := make(map[string]string)
+	modifiers := make(map[string]map[string]string)
+	err := parseBytes(src, vars, modifiers)
 
-	return out, err
+	return vars, modifiers, err
 }
 
 // Exec loads env vars from the specified filenames (empty map falls back to default)
@@ -125,9 +130,13 @@ func UnmarshalBytes(src []byte) (map[string]string, error) {
 // Simply hooks up os.Stdin/err/out to the command and calls Run().
 //
 // If you want more fine grained control over your command it's recommended
-// that you use `Load()` or `Read()` and the `os/exec` package yourself.
-func Exec(filenames []string, cmd string, cmdArgs []string) error {
-	if err := Load(filenames...); err != nil {
+// that you use `Load()`, `Overload()` or `Read()` and the `os/exec` package yourself.
+func Exec(filenames []string, cmd string, cmdArgs []string, overload bool) error {
+	op := Load
+	if overload {
+		op = Overload
+	}
+	if err := op(filenames...); err != nil {
 		return err
 	}
 
@@ -179,7 +188,7 @@ func filenamesOrDefault(filenames []string) []string {
 }
 
 func loadFile(filename string, overload bool) error {
-	envMap, err := readFile(filename)
+	envMap, _, err := readFile(filename)
 	if err != nil {
 		return err
 	}
@@ -200,7 +209,7 @@ func loadFile(filename string, overload bool) error {
 	return nil
 }
 
-func readFile(filename string) (envMap map[string]string, err error) {
+func readFile(filename string) (envMap map[string]string, modMap map[string]map[string]string, err error) {
 	file, err := os.Open(filename)
 	if err != nil {
 		return
@@ -210,130 +219,6 @@ func readFile(filename string) (envMap map[string]string, err error) {
 	return Parse(file)
 }
 
-var exportRegex = regexp.MustCompile(`^\s*(?:export\s+)?(.*?)\s*$`)
-
-func parseLine(line string, envMap map[string]string) (key string, value string, err error) {
-	if len(line) == 0 {
-		err = errors.New("zero length string")
-		return
-	}
-
-	// ditch the comments (but keep quoted hashes)
-	if strings.Contains(line, "#") {
-		segmentsBetweenHashes := strings.Split(line, "#")
-		quotesAreOpen := false
-		var segmentsToKeep []string
-		for _, segment := range segmentsBetweenHashes {
-			if strings.Count(segment, "\"") == 1 || strings.Count(segment, "'") == 1 {
-				if quotesAreOpen {
-					quotesAreOpen = false
-					segmentsToKeep = append(segmentsToKeep, segment)
-				} else {
-					quotesAreOpen = true
-				}
-			}
-
-			if len(segmentsToKeep) == 0 || quotesAreOpen {
-				segmentsToKeep = append(segmentsToKeep, segment)
-			}
-		}
-
-		line = strings.Join(segmentsToKeep, "#")
-	}
-
-	firstEquals := strings.Index(line, "=")
-	firstColon := strings.Index(line, ":")
-	splitString := strings.SplitN(line, "=", 2)
-	if firstColon != -1 && (firstColon < firstEquals || firstEquals == -1) {
-		//this is a yaml-style line
-		splitString = strings.SplitN(line, ":", 2)
-	}
-
-	if len(splitString) != 2 {
-		err = errors.New("can't separate key from value")
-		return
-	}
-
-	// Parse the key
-	key = splitString[0]
-
-	key = strings.TrimPrefix(key, "export")
-
-	key = strings.TrimSpace(key)
-
-	key = exportRegex.ReplaceAllString(splitString[0], "$1")
-
-	// Parse the value
-	value = parseValue(splitString[1], envMap)
-	return
-}
-
-var (
-	singleQuotesRegex  = regexp.MustCompile(`\A'(.*)'\z`)
-	doubleQuotesRegex  = regexp.MustCompile(`\A"(.*)"\z`)
-	escapeRegex        = regexp.MustCompile(`\\.`)
-	unescapeCharsRegex = regexp.MustCompile(`\\([^$])`)
-)
-
-func parseValue(value string, envMap map[string]string) string {
-
-	// trim
-	value = strings.Trim(value, " ")
-
-	// check if we've got quoted values or possible escapes
-	if len(value) > 1 {
-		singleQuotes := singleQuotesRegex.FindStringSubmatch(value)
-
-		doubleQuotes := doubleQuotesRegex.FindStringSubmatch(value)
-
-		if singleQuotes != nil || doubleQuotes != nil {
-			// pull the quotes off the edges
-			value = value[1 : len(value)-1]
-		}
-
-		if doubleQuotes != nil {
-			// expand newlines
-			value = escapeRegex.ReplaceAllStringFunc(value, func(match string) string {
-				c := strings.TrimPrefix(match, `\`)
-				switch c {
-				case "n":
-					return "\n"
-				case "r":
-					return "\r"
-				default:
-					return match
-				}
-			})
-			// unescape characters
-			value = unescapeCharsRegex.ReplaceAllString(value, "$1")
-		}
-
-		if singleQuotes == nil {
-			value = expandVariables(value, envMap)
-		}
-	}
-
-	return value
-}
-
-var expandVarRegex = regexp.MustCompile(`(\\)?(\$)(\()?\{?([A-Z0-9_]+)?\}?`)
-
-func expandVariables(v string, m map[string]string) string {
-	return expandVarRegex.ReplaceAllStringFunc(v, func(s string) string {
-		submatch := expandVarRegex.FindStringSubmatch(s)
-
-		if submatch == nil {
-			return s
-		}
-		if submatch[1] == "\\" || submatch[2] == "(" {
-			return submatch[0][1:]
-		} else if submatch[4] != "" {
-			return m[submatch[4]]
-		}
-		return s
-	})
-}
-
 func doubleQuoteEscape(line string) string {
 	for _, c := range doubleQuoteSpecialChars {
 		toReplace := "\\" + string(c)

godotenv_test.go

@@ -12,9 +12,13 @@ import (
 var noopPresets = make(map[string]string)
 
 func parseAndCompare(t *testing.T, rawEnvLine string, expectedKey string, expectedValue string) {
-	key, value, _ := parseLine(rawEnvLine, noopPresets)
-	if key != expectedKey || value != expectedValue {
-		t.Errorf("Expected '%v' to parse as '%v' => '%v', got '%v' => '%v' instead", rawEnvLine, expectedKey, expectedValue, key, value)
+	result, _, err := Unmarshal(rawEnvLine)
+	if err != nil {
+		t.Errorf("Expected %q to parse as %q: %q, errored %q", rawEnvLine, expectedKey, expectedValue, err)
+		return
+	}
+	if result[expectedKey] != expectedValue {
+		t.Errorf("Expected '%v' to parse as '%v' => '%v', got %q instead", rawEnvLine, expectedKey, expectedValue, result)
 	}
 }
 
@@ -80,9 +84,10 @@ func TestReadPlainEnv(t *testing.T) {
 		"OPTION_E": "5",
 		"OPTION_F": "",
 		"OPTION_G": "",
+		"OPTION_H": "1 2",
 	}
 
-	envMap, err := Read(envFileName)
+	envMap, _, err := Read(envFileName)
 	if err != nil {
 		t.Error("Error reading file")
 	}
@@ -99,7 +104,7 @@ func TestReadPlainEnv(t *testing.T) {
 }
 
 func TestParse(t *testing.T) {
-	envMap, err := Parse(bytes.NewReader([]byte("ONE=1\nTWO='2'\nTHREE = \"3\"")))
+	envMap, _, err := Parse(bytes.NewReader([]byte("ONE=1\nTWO='2'\nTHREE = \"3\"")))
 	expectedValues := map[string]string{
 		"ONE":   "1",
 		"TWO":   "2",
@@ -153,6 +158,7 @@ func TestLoadPlainEnv(t *testing.T) {
 		"OPTION_C": "3",
 		"OPTION_D": "4",
 		"OPTION_E": "5",
+		"OPTION_H": "1 2",
 	}
 
 	loadEnvAndCompareValues(t, Load, envFileName, expectedValues, noopPresets)
@@ -261,7 +267,7 @@ func TestExpanding(t *testing.T) {
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			env, err := Parse(strings.NewReader(tt.input))
+			env, _, err := Parse(strings.NewReader(tt.input))
 			if err != nil {
 				t.Errorf("Error: %s", err.Error())
 			}
@@ -272,7 +278,6 @@ func TestExpanding(t *testing.T) {
 			}
 		})
 	}
-
 }
 
 func TestVariableStringValueSeparator(t *testing.T) {
@@ -280,7 +285,7 @@ func TestVariableStringValueSeparator(t *testing.T) {
 	want := map[string]string{
 		"TEST_URLS": "stratum+tcp://stratum.antpool.com:3333\nstratum+tcp://stratum.antpool.com:443",
 	}
-	got, err := Parse(strings.NewReader(input))
+	got, _, err := Parse(strings.NewReader(input))
 	if err != nil {
 		t.Error(err)
 	}
@@ -336,7 +341,7 @@ func TestParsing(t *testing.T) {
 	// parses yaml style options
 	parseAndCompare(t, "OPTION_A: 1", "OPTION_A", "1")
 
-	//parses yaml values with equal signs
+	// parses yaml values with equal signs
 	parseAndCompare(t, "OPTION_A: Foo=bar", "OPTION_A", "Foo=bar")
 
 	// parses non-yaml options with colons
@@ -369,6 +374,9 @@ func TestParsing(t *testing.T) {
 	// expect(env('foo=bar ')).to eql('foo' => 'bar') # not 'bar '
 	parseAndCompare(t, "FOO=bar ", "FOO", "bar")
 
+	// unquoted internal whitespace is preserved
+	parseAndCompare(t, `KEY=value value`, "KEY", "value value")
+
 	// it 'ignores inline comments' do
 	// expect(env("foo=bar # this is foo")).to eql('foo' => 'bar')
 	parseAndCompare(t, "FOO=bar # this is foo", "FOO", "bar")
@@ -385,16 +393,14 @@ func TestParsing(t *testing.T) {
 	parseAndCompare(t, `FOO="ba#r"`, "FOO", "ba#r")
 	parseAndCompare(t, "FOO='ba#r'", "FOO", "ba#r")
 
-	//newlines and backslashes should be escaped
+	// newlines and backslashes should be escaped
 	parseAndCompare(t, `FOO="bar\n\ b\az"`, "FOO", "bar\n baz")
 	parseAndCompare(t, `FOO="bar\\\n\ b\az"`, "FOO", "bar\\\n baz")
 	parseAndCompare(t, `FOO="bar\\r\ b\az"`, "FOO", "bar\\r baz")
 
 	parseAndCompare(t, `="value"`, "", "value")
-	parseAndCompare(t, `KEY="`, "KEY", "\"")
-	parseAndCompare(t, `KEY="value`, "KEY", "\"value")
 
-	// leading whitespace should be ignored
+	// unquoted whitespace around keys should be ignored
 	parseAndCompare(t, " KEY =value", "KEY", "value")
 	parseAndCompare(t, "   KEY=value", "KEY", "value")
 	parseAndCompare(t, "\tKEY=value", "KEY", "value")
@@ -402,7 +408,7 @@ func TestParsing(t *testing.T) {
 	// it 'throws an error if line format is incorrect' do
 	// expect{env('lol$wut')}.to raise_error(Dotenv::FormatError)
 	badlyFormattedLine := "lol$wut"
-	_, _, err := parseLine(badlyFormattedLine, noopPresets)
+	_, _, err := Unmarshal(badlyFormattedLine)
 	if err == nil {
 		t.Errorf("Expected \"%v\" to return error, but it didn't", badlyFormattedLine)
 	}
@@ -446,7 +452,7 @@ func TestLinesToIgnore(t *testing.T) {
 
 func TestErrorReadDirectory(t *testing.T) {
 	envFileName := "fixtures/"
-	envMap, err := Read(envFileName)
+	envMap, _, err := Read(envFileName)
 
 	if err == nil {
 		t.Errorf("Expected error, got %v", envMap)
@@ -455,7 +461,7 @@ func TestErrorReadDirectory(t *testing.T) {
 
 func TestErrorParsing(t *testing.T) {
 	envFileName := "fixtures/invalid1.env"
-	envMap, err := Read(envFileName)
+	envMap, _, err := Read(envFileName)
 	if err == nil {
 		t.Errorf("Expected error, got %v", envMap)
 	}
@@ -474,20 +480,20 @@ func TestComments(t *testing.T) {
 
 func TestWrite(t *testing.T) {
 	writeAndCompare := func(env string, expected string) {
-		envMap, _ := Unmarshal(env)
+		envMap, _, _ := Unmarshal(env)
 		actual, _ := Marshal(envMap)
 		if expected != actual {
 			t.Errorf("Expected '%v' (%v) to write as '%v', got '%v' instead.", env, envMap, expected, actual)
 		}
 	}
-	//just test some single lines to show the general idea
-	//TestRoundtrip makes most of the good assertions
+	// just test some single lines to show the general idea
+	// TestRoundtrip makes most of the good assertions
 
-	//values are always double-quoted
+	// values are always double-quoted
 	writeAndCompare(`key=value`, `key="value"`)
-	//double-quotes are escaped
+	// double-quotes are escaped
 	writeAndCompare(`key=va"lu"e`, `key="va\"lu\"e"`)
-	//but single quotes are left alone
+	// but single quotes are left alone
 	writeAndCompare(`key=va'lu'e`, `key="va'lu'e"`)
 	// newlines, backslashes, and some other special chars are escaped
 	writeAndCompare(`foo="\n\r\\r!"`, `foo="\n\r\\r\!"`)
@@ -495,14 +501,13 @@ func TestWrite(t *testing.T) {
 	writeAndCompare("foo=bar\nbaz=buzz", "baz=\"buzz\"\nfoo=\"bar\"")
 	// integers should not be quoted
 	writeAndCompare(`key="10"`, `key=10`)
-
 }
 
 func TestRoundtrip(t *testing.T) {
 	fixtures := []string{"equals.env", "exported.env", "plain.env", "quoted.env"}
 	for _, fixture := range fixtures {
 		fixtureFilename := fmt.Sprintf("fixtures/%s", fixture)
-		env, err := readFile(fixtureFilename)
+		env, _, err := readFile(fixtureFilename)
 		if err != nil {
 			t.Errorf("Expected '%s' to read without error (%v)", fixtureFilename, err)
 		}
@@ -510,7 +515,7 @@ func TestRoundtrip(t *testing.T) {
 		if err != nil {
 			t.Errorf("Expected '%s' to Marshal (%v)", fixtureFilename, err)
 		}
-		roundtripped, err := Unmarshal(rep)
+		roundtripped, _, err := Unmarshal(rep)
 		if err != nil {
 			t.Errorf("Expected '%s' to Mashal and Unmarshal (%v)", fixtureFilename, err)
 		}
@@ -520,3 +525,185 @@ func TestRoundtrip(t *testing.T) {
 
 	}
 }
+
+func TestTrailingNewlines(t *testing.T) {
+	cases := map[string]struct {
+		input string
+		key   string
+		value string
+	}{
+		"Simple value without trailing newline": {
+			input: "KEY=value",
+			key:   "KEY",
+			value: "value",
+		},
+		"Value with internal whitespace without trailing newline": {
+			input: "KEY=value value",
+			key:   "KEY",
+			value: "value value",
+		},
+		"Value with internal whitespace with trailing newline": {
+			input: "KEY=value value\n",
+			key:   "KEY",
+			value: "value value",
+		},
+		"YAML style - value with internal whitespace without trailing newline": {
+			input: "KEY: value value",
+			key:   "KEY",
+			value: "value value",
+		},
+		"YAML style - value with internal whitespace with trailing newline": {
+			input: "KEY: value value\n",
+			key:   "KEY",
+			value: "value value",
+		},
+	}
+
+	for n, c := range cases {
+		t.Run(n, func(t *testing.T) {
+			result, _, err := Unmarshal(c.input)
+			if err != nil {
+				t.Errorf("Input: %q Unexpected error:\t%q", c.input, err)
+			}
+			if result[c.key] != c.value {
+				t.Errorf("Input %q Expected:\t %q/%q\nGot:\t %q", c.input, c.key, c.value, result)
+			}
+		})
+	}
+}
+
+func TestWhitespace(t *testing.T) {
+	cases := map[string]struct {
+		input string
+		key   string
+		value string
+	}{
+		"Leading whitespace": {
+			input: " A=a\n",
+			key:   "A",
+			value: "a",
+		},
+		"Leading tab": {
+			input: "\tA=a\n",
+			key:   "A",
+			value: "a",
+		},
+		"Leading mixed whitespace": {
+			input: " \t \t\n\t \t A=a\n",
+			key:   "A",
+			value: "a",
+		},
+		"Leading whitespace before export": {
+			input: " \t\t export    A=a\n",
+			key:   "A",
+			value: "a",
+		},
+		"Trailing whitespace": {
+			input: "A=a \t \t\n",
+			key:   "A",
+			value: "a",
+		},
+		"Trailing whitespace with export": {
+			input: "export A=a\t \t \n",
+			key:   "A",
+			value: "a",
+		},
+		"No EOL": {
+			input: "A=a",
+			key:   "A",
+			value: "a",
+		},
+		"Trailing whitespace with no EOL": {
+			input: "A=a ",
+			key:   "A",
+			value: "a",
+		},
+	}
+
+	for n, c := range cases {
+		t.Run(n, func(t *testing.T) {
+			result, _, err := Unmarshal(c.input)
+			if err != nil {
+				t.Errorf("Input: %q Unexpected error:\t%q", c.input, err)
+			}
+			if result[c.key] != c.value {
+				t.Errorf("Input %q Expected:\t %q/%q\nGot:\t %q", c.input, c.key, c.value, result)
+			}
+		})
+	}
+}
+
+func TestModfiers(t *testing.T) {
+	cases := map[string]struct {
+		input     string
+		key       string
+		value     string
+		modifiers map[string]string
+	}{
+		"No Modifier": {
+			input: "A=a",
+			key:   "A",
+			value: "a",
+		},
+		"With comment": {
+			input: "A=a # my comment",
+			key:   "A",
+			value: "a",
+		},
+		"With single modifier": {
+			input: "A=a # foo=bar",
+			key:   "A",
+			value: "a",
+			modifiers: map[string]string{
+				"foo": "bar",
+			},
+		},
+		"With multiple modifiers": {
+			input: "A=a # foo=bar length=10",
+			key:   "A",
+			value: "a",
+			modifiers: map[string]string{
+				"foo":    "bar",
+				"length": "10",
+			},
+		},
+		"With quoted var": {
+			input: "A='a' # foo=bar",
+			key:   "A",
+			value: "a",
+			modifiers: map[string]string{
+				"foo": "bar",
+			},
+		},
+		"With quoted var 2": {
+			input: "A='a' # foo=bar\nB=b",
+			key:   "A",
+			value: "a",
+			modifiers: map[string]string{
+				"foo": "bar",
+			},
+		},
+	}
+
+	for n, c := range cases {
+		t.Run(n, func(t *testing.T) {
+			values, modifiers, err := Unmarshal(c.input)
+			if err != nil {
+				t.Errorf("Input: %q Unexpected error:\t%q", c.input, err)
+			}
+			if values[c.key] != c.value {
+				t.Errorf("Input %q Expected:\t %q/%q\nGot:\t %q", c.input, c.key, c.value, values)
+			}
+
+			if modifiers[c.key] == nil && c.modifiers != nil {
+				t.Errorf("Input %q Expected modifiers\n Got: none", c.input)
+			} else {
+				for k, v := range c.modifiers {
+					if modifiers[c.key][k] != v {
+						t.Errorf("Input %q Expected modifier %s=%s\n Got: %s=%s", c.input, k, v, k, modifiers[c.key][k])
+					}
+				}
+			}
+		})
+	}
+}

parser.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"errors"
 	"fmt"
+	"regexp"
 	"strings"
 	"unicode"
 )
@@ -16,7 +17,7 @@ const (
 	exportPrefix = "export"
 )
 
-func parseBytes(src []byte, out map[string]string) error {
+func parseBytes(src []byte, vars map[string]string, modifiers map[string]map[string]string) error {
 	src = bytes.Replace(src, []byte("\r\n"), []byte("\n"), -1)
 	cutset := src
 	for {
@@ -31,12 +32,13 @@ func parseBytes(src []byte, out map[string]string) error {
 			return err
 		}
 
-		value, left, err := extractVarValue(left, out)
+		value, mods, left, err := extractVarValue(left, vars)
 		if err != nil {
 			return err
 		}
 
-		out[key] = value
+		vars[key] = value
+		modifiers[key] = mods
 		cutset = left
 	}
 
@@ -69,7 +71,13 @@ func getStatementStart(src []byte) []byte {
 // locateKeyName locates and parses key name and returns rest of slice
 func locateKeyName(src []byte) (key string, cutset []byte, err error) {
 	// trim "export" and space at beginning
-	src = bytes.TrimLeftFunc(bytes.TrimPrefix(src, []byte(exportPrefix)), isSpace)
+	src = bytes.TrimLeftFunc(src, isSpace)
+	if bytes.HasPrefix(src, []byte(exportPrefix)) {
+		trimmed := bytes.TrimPrefix(src, []byte(exportPrefix))
+		if bytes.IndexFunc(trimmed, isSpace) == 0 {
+			src = bytes.TrimLeftFunc(trimmed, isSpace)
+		}
+	}
 
 	// locate key name end and validate it in single loop
 	offset := 0
@@ -88,8 +96,8 @@ loop:
 			break loop
 		case '_':
 		default:
-			// variable name should match [A-Za-z0-9_]
-			if unicode.IsLetter(rchar) || unicode.IsNumber(rchar) {
+			// variable name should match [A-Za-z0-9_.]
+			if unicode.IsLetter(rchar) || unicode.IsNumber(rchar) || rchar == '.' {
 				continue
 			}
 
@@ -110,16 +118,44 @@ loop:
 }
 
 // extractVarValue extracts variable value and returns rest of slice
-func extractVarValue(src []byte, vars map[string]string) (value string, rest []byte, err error) {
+func extractVarValue(src []byte, vars map[string]string) (value string, modifiers map[string]string, rest []byte, err error) {
 	quote, hasPrefix := hasQuotePrefix(src)
+	// unquoted value - read until end of line
+	endOfLine := bytes.IndexFunc(src, isLineEnd)
+	// Hit EOF without a trailing newline
+	if endOfLine == -1 {
+		endOfLine = len(src)
+
+		if endOfLine == 0 {
+			return "", nil, nil, nil
+		}
+	}
 	if !hasPrefix {
-		// unquoted value - read until whitespace
-		end := bytes.IndexFunc(src, unicode.IsSpace)
-		if end == -1 {
-			return expandVariables(string(src), vars), nil, nil
+		// Convert line to rune away to do accurate countback of runes
+		line := []rune(string(src[0:endOfLine]))
+
+		// Assume end of line is end of var
+		endOfVar := len(line)
+		if endOfVar == 0 {
+			return "", nil, src[endOfLine:], nil
 		}
 
-		return expandVariables(string(src[0:end]), vars), src[end:], nil
+		comment := ""
+		// Work backwards to check if the line ends in whitespace then
+		// a comment (ie asdasd # some comment)
+		for i := endOfVar - 1; i >= 0; i-- {
+			if line[i] == charComment && i > 0 {
+				comment = string(line[i+1:])
+				if isSpace(line[i-1]) {
+					endOfVar = i
+					break
+				}
+			}
+		}
+
+		trimmed := strings.TrimFunc(string(line[0:endOfVar]), isSpace)
+
+		return expandVariables(trimmed, vars), extractModifiers(comment), src[endOfLine:], nil
 	}
 
 	// lookup quoted string terminator
@@ -142,7 +178,11 @@ func extractVarValue(src []byte, vars map[string]string) (value string, rest []b
 			value = expandVariables(expandEscapes(value), vars)
 		}
 
-		return value, src[i+1:], nil
+		var mods map[string]string
+		if endOfLine > i {
+			mods = extractModifiers(string(src[i+1 : endOfLine]))
+		}
+		return value, mods, src[i+1:], nil
 	}
 
 	// return formatted error if quoted string is not terminated
@@ -151,7 +191,24 @@ func extractVarValue(src []byte, vars map[string]string) (value string, rest []b
 		valEndIndex = len(src)
 	}
 
-	return "", nil, fmt.Errorf("unterminated quoted value %s", src[:valEndIndex])
+	return "", nil, nil, fmt.Errorf("unterminated quoted value %s", src[:valEndIndex])
+}
+
+func extractModifiers(comment string) map[string]string {
+	if comment == "" {
+		return nil
+	}
+	comment = strings.TrimSpace(comment)
+	kvpairs := strings.Split(comment, " ")
+	mods := make(map[string]string)
+	for _, kv := range kvpairs {
+		kvsplit := strings.Split(kv, "=")
+		if len(kvsplit) != 2 {
+			continue
+		}
+		mods[kvsplit[0]] = kvsplit[1]
+	}
+	return mods
 }
 
 func expandEscapes(str string) string {
@@ -205,3 +262,32 @@ func isSpace(r rune) bool {
 	}
 	return false
 }
+
+func isLineEnd(r rune) bool {
+	if r == '\n' || r == '\r' {
+		return true
+	}
+	return false
+}
+
+var (
+	escapeRegex        = regexp.MustCompile(`\\.`)
+	expandVarRegex     = regexp.MustCompile(`(\\)?(\$)(\()?\{?([A-Z0-9_]+)?\}?`)
+	unescapeCharsRegex = regexp.MustCompile(`\\([^$])`)
+)
+
+func expandVariables(v string, m map[string]string) string {
+	return expandVarRegex.ReplaceAllStringFunc(v, func(s string) string {
+		submatch := expandVarRegex.FindStringSubmatch(s)
+
+		if submatch == nil {
+			return s
+		}
+		if submatch[1] == "\\" || submatch[2] == "(" {
+			return submatch[0][1:]
+		} else if submatch[4] != "" {
+			return m[submatch[4]]
+		}
+		return s
+	})
+}