File size: 4,316 Bytes
8c763fb | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 | // Copyright (c) Microsoft Corporation.
// Licensed under the MIT License.
using System.Management.Automation;
using System.Text;
// TODO/FIXME: move this to Microsoft.PowerShell.Cim namespace (and move in source depot folder as well)
namespace Microsoft.PowerShell.Cmdletization.Cim
{
/// <summary>
/// Translates a <see cref="WildcardPattern"/> into a like-operand for WQL.
/// </summary>
/// <remarks>
/// Documentation on MSDN (https://msdn.microsoft.com/library/aa392263(VS.85).aspx) is
/// 1) rather slim / incomplete
/// 2) sometimes incorrect (i.e. says that '=' is used for character ranges, when it should have said '-')
///
/// The code below is therefore mainly based on reverse engineering of admin\wmi\wbem\winmgmt\wbecomn\like.cpp
/// </remarks>
internal class WildcardPatternToCimQueryParser : WildcardPatternParser
{
private readonly StringBuilder _result = new();
private bool _needClientSideFiltering;
protected override void AppendLiteralCharacter(char c)
{
switch (c)
{
case '%':
case '_':
case '[': // no need to escape ']' character
this.BeginBracketExpression();
this.AppendLiteralCharacterToBracketExpression(c);
this.EndBracketExpression();
break;
default:
_result.Append(c);
break;
}
}
protected override void AppendAsterix()
{
_result.Append('%');
}
protected override void AppendQuestionMark()
{
_result.Append('_');
}
protected override void BeginBracketExpression()
{
_result.Append('[');
}
protected override void AppendLiteralCharacterToBracketExpression(char c)
{
switch (c)
{
case '^':
case ']':
case '-':
case '\\':
this.AppendCharacterRangeToBracketExpression(c, c);
break;
default:
_result.Append(c);
break;
}
}
protected override void AppendCharacterRangeToBracketExpression(char startOfCharacterRange, char endOfCharacterRange)
{
// 90 = Z
// 91 = [
// 92 = \
// 93 = ]
// 94 = ^
// 95 = _
if ((startOfCharacterRange >= 91) && (startOfCharacterRange <= 94))
{
startOfCharacterRange = (char)90;
_needClientSideFiltering = true;
}
if ((endOfCharacterRange >= 91) && (endOfCharacterRange <= 94))
{
endOfCharacterRange = (char)95;
_needClientSideFiltering = true;
}
// 44 = ,
// 45 = -
// 46 = .
if (startOfCharacterRange == 45)
{
startOfCharacterRange = (char)44;
_needClientSideFiltering = true;
}
if (endOfCharacterRange == 45)
{
endOfCharacterRange = (char)46;
_needClientSideFiltering = true;
}
_result.Append(startOfCharacterRange);
_result.Append('-');
_result.Append(endOfCharacterRange);
}
protected override void EndBracketExpression()
{
_result.Append(']');
}
/// <summary>
/// Converts <paramref name="wildcardPattern"/> into a value of a right-hand-side operand of LIKE operator of a WQL query.
/// Return value still has to be string-escaped (i.e. by doubling '\'' character), before embedding it into a query.
/// </summary>
internal static string Parse(WildcardPattern wildcardPattern, out bool needsClientSideFiltering)
{
var parser = new WildcardPatternToCimQueryParser();
WildcardPatternParser.Parse(wildcardPattern, parser);
needsClientSideFiltering = parser._needClientSideFiltering;
return parser._result.ToString();
}
}
}
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