shellQuote function

String shellQuote(String input)

Quote a string for safe shell usage.

Uses single quotes by default. If the string contains single quotes, uses the $'...' ANSI-C quoting form. If the string is a simple alphanumeric/dash/underscore string, returns it unquoted.

Implementation

String shellQuote(String input) {
  if (input.isEmpty) return "''";

  // Check if quoting is needed at all.
  if (RegExp(r'^[a-zA-Z0-9._/=:@%^,+-]+$').hasMatch(input)) {
    return input;
  }

  // If no single quotes, wrap in single quotes.
  if (!input.contains("'")) {
    return "'$input'";
  }

  // Use $'...' form for strings with single quotes.
  final escaped = input
      .replaceAll('\\', '\\\\')
      .replaceAll("'", "\\'")
      .replaceAll('\n', '\\n')
      .replaceAll('\t', '\\t')
      .replaceAll('\r', '\\r')
      .replaceAll('\x07', '\\a')
      .replaceAll('\b', '\\b')
      .replaceAll('\x1B', '\\e');
  return "\$'$escaped'";
}