150 lines
2.3 KiB
Go
150 lines
2.3 KiB
Go
package shellwords
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import (
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"fmt"
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"strings"
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)
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// WordOffset is the offset from the position cursor to print on the error.
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const WordOffset = 7
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var escaper = strings.NewReplacer(
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"`", "\\`",
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"@", "\\@",
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"\\", "\\\\",
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)
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type ErrParse struct {
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Position int
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Words string // joined
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}
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func (e ErrParse) Error() string {
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// Magic number 5.
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var a = max(0, e.Position-WordOffset)
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var b = min(len(e.Words), e.Position+WordOffset)
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var word = e.Words[a:b]
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var uidx = e.Position - a
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errstr := strings.Builder{}
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errstr.WriteString("Unexpected quote or escape")
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// Do a bound check.
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if uidx+1 > len(word) {
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// Invalid.
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errstr.WriteString(".")
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return errstr.String()
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}
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// Write the pre-underline part.
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fmt.Fprintf(
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&errstr, ": %s__%s__",
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escaper.Replace(word[:uidx]),
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escaper.Replace(string(word[uidx:])),
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)
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return errstr.String()
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}
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// Parse parses the given text to a slice of words.
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func Parse(line string) ([]string, error) {
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var args []string
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var escaped, doubleQuoted, singleQuoted bool
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var buf strings.Builder
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buf.Grow(len(line))
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got := false
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cursor := 0
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runes := []rune(line)
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for _, r := range runes {
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if escaped {
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buf.WriteRune(r)
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escaped = false
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continue
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}
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if r == '\\' {
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if singleQuoted {
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buf.WriteRune(r)
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} else {
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escaped = true
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}
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continue
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}
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if isSpace(r) {
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switch {
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case singleQuoted, doubleQuoted:
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buf.WriteRune(r)
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case got:
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cursor += buf.Len()
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args = append(args, buf.String())
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buf.Reset()
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got = false
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}
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continue
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}
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switch r {
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case '"':
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if !singleQuoted {
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if doubleQuoted {
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got = true
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}
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doubleQuoted = !doubleQuoted
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continue
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}
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case '\'', '`':
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if !doubleQuoted {
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if singleQuoted {
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got = true
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}
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singleQuoted = !singleQuoted
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continue
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}
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}
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got = true
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buf.WriteRune(r)
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}
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if got {
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args = append(args, buf.String())
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}
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if escaped || singleQuoted || doubleQuoted {
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return args, &ErrParse{
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Position: cursor + buf.Len(),
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Words: strings.Join(args, " "),
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}
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}
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return args, nil
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}
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func isSpace(r rune) bool {
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switch r {
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case ' ', '\t', '\r', '\n', ' ':
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return true
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}
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return false
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}
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func min(i, j int) int {
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if i < j {
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return i
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}
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return j
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}
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func max(i, j int) int {
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if i < j {
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return j
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}
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return i
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}
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