Change project layout and use go.mod

pkg/shellwords/shellwords.go

@@ -0,0 +1,180 @@
+package shellwords
+
+import (
+	"bytes"
+	"errors"
+	"os"
+	"regexp"
+)
+
+var envRe = regexp.MustCompile(`\$({[a-zA-Z0-9_]+}|[a-zA-Z0-9_]+)`)
+
+func isSpace(r rune) bool {
+	switch r {
+	case ' ', '\t', '\r', '\n':
+		return true
+	}
+	return false
+}
+
+func replaceEnv(s string) string {
+	return envRe.ReplaceAllStringFunc(s, func(s string) string {
+		s = s[1:]
+		if s[0] == '{' {
+			s = s[1 : len(s)-1]
+		}
+		return os.Getenv(s)
+	})
+}
+
+type Parser struct {
+	Position int
+}
+
+func NewParser() *Parser {
+	return &Parser{0}
+}
+
+func (p *Parser) Parse(line string) ([]string, error) {
+	args := []string{}
+	buf := ""
+	var escaped, doubleQuoted, singleQuoted, backQuote, dollarQuote bool
+	backtick := ""
+
+	pos := -1
+	got := false
+
+loop:
+	for i, r := range line {
+		if escaped {
+			buf += string(r)
+			escaped = false
+			continue
+		}
+
+		if r == '\\' {
+			if singleQuoted {
+				buf += string(r)
+			} else {
+				escaped = true
+			}
+			continue
+		}
+
+		if isSpace(r) {
+			if singleQuoted || doubleQuoted || backQuote || dollarQuote {
+				buf += string(r)
+				backtick += string(r)
+			} else if got {
+				buf = replaceEnv(buf)
+				args = append(args, buf)
+				buf = ""
+				got = false
+			}
+			continue
+		}
+
+		switch r {
+		case '`':
+			if !singleQuoted && !doubleQuoted && !dollarQuote {
+				if backQuote {
+					out, err := shellRun(backtick)
+					if err != nil {
+						return nil, err
+					}
+					buf = out
+				}
+				backtick = ""
+				backQuote = !backQuote
+				continue
+				backtick = ""
+				backQuote = !backQuote
+			}
+		case ')':
+			if !singleQuoted && !doubleQuoted && !backQuote {
+				if dollarQuote {
+					out, err := shellRun(backtick)
+					if err != nil {
+						return nil, err
+					}
+					buf = out
+				}
+				backtick = ""
+				dollarQuote = !dollarQuote
+				continue
+				backtick = ""
+				dollarQuote = !dollarQuote
+			}
+		case '(':
+			if !singleQuoted && !doubleQuoted && !backQuote {
+				if !dollarQuote && len(buf) > 0 && buf == "$" {
+					dollarQuote = true
+					buf += "("
+					continue
+				} else {
+					return nil, errors.New("invalid command line string")
+				}
+			}
+		case '"':
+			if !singleQuoted && !dollarQuote {
+				doubleQuoted = !doubleQuoted
+				continue
+			}
+		case '\'':
+			if !doubleQuoted && !dollarQuote {
+				singleQuoted = !singleQuoted
+				continue
+			}
+		case ';', '&', '|', '<', '>':
+			if !(escaped || singleQuoted || doubleQuoted || backQuote) {
+				pos = i
+				break loop
+			}
+		}
+
+		got = true
+		buf += string(r)
+		if backQuote || dollarQuote {
+			backtick += string(r)
+		}
+	}
+
+	buf = replaceEnv(buf)
+	args = append(args, buf)
+
+	if escaped || singleQuoted || doubleQuoted || backQuote || dollarQuote {
+		return nil, errors.New("invalid command line string")
+	}
+
+	p.Position = pos
+
+	return args, nil
+}
+
+func Split(line string) ([]string, error) {
+	return NewParser().Parse(line)
+}
+
+func Join(args ...string) string {
+	var buf bytes.Buffer
+	for i, w := range args {
+		if i != 0 {
+			buf.WriteByte(' ')
+		}
+		if w == "" {
+			buf.WriteString("''")
+			continue
+		}
+
+		for _, b := range w {
+			switch b {
+			case ' ', '\t', '\r', '\n':
+				buf.WriteByte('\\')
+				buf.WriteString(string(b))
+			default:
+				buf.WriteString(string(b))
+			}
+		}
+	}
+	return buf.String()
+}