feat: filebrowser with encfs

files/utils.go

@@ -0,0 +1,59 @@
+package files
+
+import (
+	"os"
+	"unicode/utf8"
+)
+
+func isBinary(content []byte) bool {
+	maybeStr := string(content)
+	runeCnt := utf8.RuneCount(content)
+	runeIndex := 0
+	gotRuneErrCnt := 0
+	firstRuneErrIndex := -1
+
+	const (
+		// 8 and below are control chars (e.g. backspace, null, eof, etc)
+		maxControlCharsCode = 8
+		// 0xFFFD(65533) is  the "error" Rune or "Unicode replacement character"
+		// see https://golang.org/pkg/unicode/utf8/#pkg-constants
+		unicodeReplacementChar = 0xFFFD
+	)
+
+	for _, b := range maybeStr {
+		if b <= maxControlCharsCode {
+			return true
+		}
+
+		if b == unicodeReplacementChar {
+			// if it is not the last (utf8.UTFMax - x) rune
+			if runeCnt > utf8.UTFMax && runeIndex < runeCnt-utf8.UTFMax {
+				return true
+			}
+			// else it is the last (utf8.UTFMax - x) rune
+			// there maybe Vxxx, VVxx, VVVx, thus, we may got max 3 0xFFFD rune (assume V is the byte we got)
+			// for Chinese, it can only be Vxx, VVx, we may got max 2 0xFFFD rune
+			gotRuneErrCnt++
+
+			// mark the first time
+			if firstRuneErrIndex == -1 {
+				firstRuneErrIndex = runeIndex
+			}
+		}
+		runeIndex++
+	}
+
+	// if last (utf8.UTFMax - x ) rune has the "error" Rune, but not all
+	if firstRuneErrIndex != -1 && gotRuneErrCnt != runeCnt-firstRuneErrIndex {
+		return true
+	}
+	return false
+}
+
+func IsNamedPipe(mode os.FileMode) bool {
+	return mode&os.ModeNamedPipe != 0
+}
+
+func IsSymlink(mode os.FileMode) bool {
+	return mode&os.ModeSymlink != 0
+}