DockerCLI/vendor/github.com/mattn/go-shellwords/shellwords.go

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package shellwords
import (
"errors"
"os"
"regexp"
)
var (
ParseEnv bool = false
ParseBacktick bool = false
)
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 {
ParseEnv bool
ParseBacktick bool
Position int
}
func NewParser() *Parser {
return &Parser{ParseEnv, ParseBacktick, 0}
}
func (p *Parser) Parse(line string) ([]string, error) {
args := []string{}
buf := ""
var escaped, doubleQuoted, singleQuoted, backQuote 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 {
buf += string(r)
backtick += string(r)
} else if got {
if p.ParseEnv {
buf = replaceEnv(buf)
}
args = append(args, buf)
buf = ""
got = false
}
continue
}
switch r {
case '`':
if !singleQuoted && !doubleQuoted {
if p.ParseBacktick {
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 = !doubleQuoted
continue
}
case '\'':
if !doubleQuoted {
singleQuoted = !singleQuoted
continue
}
case ';', '&', '|', '<', '>':
if !(escaped || singleQuoted || doubleQuoted || backQuote) {
pos = i
break loop
}
}
got = true
buf += string(r)
if backQuote {
backtick += string(r)
}
}
if got {
if p.ParseEnv {
buf = replaceEnv(buf)
}
args = append(args, buf)
}
if escaped || singleQuoted || doubleQuoted || backQuote {
return nil, errors.New("invalid command line string")
}
p.Position = pos
return args, nil
}
func Parse(line string) ([]string, error) {
return NewParser().Parse(line)
}