Changeset 566 in code

Timestamp:

Jun 24, 2021, 5:33:46 PM (4 years ago)

Author:

hubert

Message:

Hand-made word splitter for BouncerServ

Remove the (direct) dependency on shlex (go-scfg still depends on it).

Co-authored-by: Simon Ser <contact@…>

Location:

trunk

Files:

• go.mod (modified) (1 diff)
• service.go (modified) (2 diffs)
• service_test.go (added)

trunk/go.mod

@@ -7 +7 @@
         git.sr.ht/~sircmpwn/go-bare v0.0.0-20210331145808-46f9b5e5bcf9
         github.com/emersion/go-sasl v0.0.0-20200509203442-7bfe0ed36a21
-        github.com/google/shlex v0.0.0-20191202100458-e7afc7fbc510
         github.com/klauspost/compress v1.11.13 // indirect
         github.com/mattn/go-sqlite3 v1.14.6

trunk/service.go

@@ -22 +22 @@
         "strings"
         "time"
-
-        "github.com/google/shlex"
+        "unicode"
+
         "golang.org/x/crypto/bcrypt"
         "gopkg.in/irc.v3"
@@ -64 +64 @@
 }
 
+func splitWords(s string) ([]string, error) {
+        var words []string
+        var lastWord strings.Builder
+        escape := false
+        prev := ' '
+        wordDelim := ' '
+
+        for _, r := range s {
+                if escape {
+                        // last char was a backslash, write the byte as-is.
+                        lastWord.WriteRune(r)
+                        escape = false
+                } else if r == '\\' {
+                        escape = true
+                } else if wordDelim == ' ' && unicode.IsSpace(r) {
+                        // end of last word
+                        if !unicode.IsSpace(prev) {
+                                words = append(words, lastWord.String())
+                                lastWord.Reset()
+                        }
+                } else if r == wordDelim {
+                        // wordDelim is either " or ', switch back to
+                        // space-delimited words.
+                        wordDelim = ' '
+                } else if r == '"' || r == '\'' {
+                        if wordDelim == ' ' {
+                                // start of (double-)quoted word
+                                wordDelim = r
+                        } else {
+                                // either wordDelim is " and r is ' or vice-versa
+                                lastWord.WriteRune(r)
+                        }
+                } else {
+                        lastWord.WriteRune(r)
+                }
+
+                prev = r
+        }
+
+        if !unicode.IsSpace(prev) {
+                words = append(words, lastWord.String())
+        }
+
+        if wordDelim != ' ' {
+                return nil, fmt.Errorf("unterminated quoted string")
+        }
+        if escape {
+                return nil, fmt.Errorf("unterminated backslash sequence")
+        }
+
+        return words, nil
+}
+
 func handleServicePRIVMSG(dc *downstreamConn, text string) {
-        words, err := shlex.Split(text)
-        if err != nil {
-                sendServicePRIVMSG(dc, fmt.Sprintf("error: failed to parse command: %v", err))
+        words, err := splitWords(text)
+        if err != nil {
+                sendServicePRIVMSG(dc, fmt.Sprintf(`error: failed to parse command: %v`, err))
                 return
         }