public static string StripStringForFilename(string input, ValidityMode vmode = ValidityMode.AllowWhitelist, char?repl = null)
{
var output = new StringBuilder(input.Length);
foreach (var c in input)
{
if (IsValidChar(c, vmode))
{
output.Append(c);
}
else
{
if (repl != null)
{
output.Append(repl);
}
}
}
var fileName = output.ToString();
if (RESERVED_FILENAMES.Any(r => string.Equals(r, fileName, StringComparison.CurrentCultureIgnoreCase)))
{
fileName = "_" + fileName;
}
if (RESERVED_FILENAMES.Any(r => fileName.ToLower().StartsWith(r.ToLower() + ".")))
{
fileName = "_" + fileName;
}
return(fileName);
}
private static bool IsValidChar(char chr, ValidityMode vmode)
{
if (vmode == ValidityMode.AllowAllCharacters)
{
return(!Path.GetInvalidFileNameChars().Contains(chr));
}
else if (vmode == ValidityMode.AllowAllLetters)
{
return(ALLOWED_CHARACTER.Contains(chr) ||
char.GetUnicodeCategory(chr) == UnicodeCategory.LetterNumber ||
char.GetUnicodeCategory(chr) == UnicodeCategory.OtherLetter ||
char.GetUnicodeCategory(chr) == UnicodeCategory.DecimalDigitNumber ||
char.GetUnicodeCategory(chr) == UnicodeCategory.UppercaseLetter ||
char.GetUnicodeCategory(chr) == UnicodeCategory.LowercaseLetter);
}
else
{
return(ALLOWED_CHARACTER.Contains(chr));
}
}
public static string ConvertStringForFilename(string input, ValidityMode vmode = ValidityMode.AllowWhitelist)
{
var output = new StringBuilder(input.Length);
foreach (var c in input)
{
if (c == CONVERT_ESCAPE_CHARACTER)
{
output.Append(CONVERT_ESCAPE_CHARACTER);
output.Append($"{(int) c:X4}");
}
else if (IsValidChar(c, vmode))
{
output.Append(c);
}
else
{
output.Append(CONVERT_ESCAPE_CHARACTER);
output.Append($"{(int) c:X4}");
}
}
var fileName = output.ToString();
if (fileName.EndsWith("."))
{
fileName = fileName.Substring(0, fileName.Length - 1) + CONVERT_ESCAPE_CHARACTER + $"{(int) '.':X4}";
}
if (RESERVED_FILENAMES.Any(r => string.Equals(r, fileName, StringComparison.CurrentCultureIgnoreCase)))
{
fileName = CONVERT_ESCAPE_CHARACTER + $"{(int) fileName[0]:X4}" + fileName.Substring(1);
}
return(fileName);
}
