The escape character of WildcardPattern is backtick. It looks like if an
input string contains backticks which are not followed by characters []?*
then WildcardPattern.Escape() keeps them intact instead of escaping each
backtick with a backtick.
Compare with Regex. The escape character is backslash. If an input string
contains backslashes then Regex.Escape() escapes each backslash with a
backslash.
By design an escaped string as a pattern should match the original string. This
is not always the case with WildcardPattern. If a string contains backticks
then its escaped pattern may not match the original string. Also, the method
WildcardPattern.UnEscape() applied to an escaped string may not produce the
original string.
One possible workaround is to escape a string using this regular expression:
$escaped = $string -replace '([`*?[\]])', '`$1'As a result, an escaped string matches the original with the operator -like
and the method WildcardPattern.UnEscape() gets the original string.
- Test-1-Escape-UnEscape-wildcard.ps1 shows that
WildcardPattern.Escape()produces a pattern not matching the original string andUnEscape()does not get the original string. - Test-2-Escape-UnEscape-regex.ps1 shows how
Regex.Escape()works in the similar case (backslashes instead of backticks). - Test-3-Escape-workaround.ps1 tests the workaround.
- Microsoft Connect 336327