public static string Unescape(this string txt)
{
if (string.IsNullOrEmpty(txt)) { return txt; }
StringBuilder retval = new StringBuilder(txt.Length);
for (int ix = 0; ix < txt.Length;)
{
int jx = txt.IndexOf('\\', ix);
if (jx < 0 || jx == txt.Length - 1) jx = txt.Length;
retval.Append(txt, ix, jx - ix);
if (jx >= txt.Length) break;
switch (txt[jx + 1])
{
case 'n': retval.Append('\n'); break; // Line feed
case 'r': retval.Append('\r'); break; // Carriage return
case 't': retval.Append('\t'); break; // Tab
case ',': retval.Append(','); break;
case '"': retval.Append('"'); break;
case '=': retval.Append('='); break;
case '\\': retval.Append('\\'); break; // Don't escape
default: // Unrecognized, copy as-is
retval.Append('\\').Append(txt[jx + 1]); break;
}
ix = jx + 2;
}
return retval.ToString();
}