_ShellExpression.cs source code in C# .NET

Source code for the .NET framework in C#

                        
Code:

                         / DotNET / DotNET / 8.0 / untmp / whidbey / REDBITS / ndp / fx / src / Net / System / Net / _ShellExpression.cs / 1 / _ShellExpression.cs
                        

                        
                            //------------------------------------------------------------------------------ 
// 
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// 
//----------------------------------------------------------------------------- 

namespace System.Net 
{ 
    using System;
 
    internal struct ShellExpression
    {
        private enum ShExpTokens
        { 
            Asterisk = -1,
            Question = -2, 
            AugmentedDot = -3, 
            AugmentedAsterisk = -4,
            AugmentedQuestion = -5, 
            Start = -6,
            End = -7
        }
 
        private ShExpTokens[] pattern;
        private int[] match; 
 
        // Normally would defer parsing, but we want to throw here if it's invalid.
        internal ShellExpression(string pattern) 
        {
            this.pattern = null;
            this.match = null;
            GlobalLog.Print("ShellServices.ShellExpression#" + ValidationHelper.HashString(this) + "::.ctor() pattern:" + ValidationHelper.ToString(pattern)); 
            Parse(pattern);
        } 
 
        /*
        // Consider removing. 
        internal void SetPattern(string pattern)
        {
            GlobalLog.Print("ShellServices.ShellExpression#" + ValidationHelper.HashString(this) + "::SetPattern() pattern:" + ValidationHelper.ToString(pattern));
            Parse(pattern); 
        }
        */ 
 
        internal bool IsMatch(string target)
        { 
            GlobalLog.Print("ShellServices.ShellExpression#" + ValidationHelper.HashString(this) + "::IsMatch() target:" + ValidationHelper.ToString(target));
            int i = 0;
            int j = 0;
            bool reverse = false; 
            bool matched = false;
 
            while (true) 
            {
                if (!reverse) 
                {
                    if (j > target.Length)
                    {
                        break; 
                    }
 
                    switch (pattern[i]) 
                    {
                        case ShExpTokens.Asterisk: 
                            match[i++] = j = target.Length;
                            continue;

                        case ShExpTokens.Question: 
                            if (j == target.Length)
                            { 
                                reverse = true; 
                            }
                            else 
                            {
                                match[i++] = ++j;
                            }
                            continue; 

                        case ShExpTokens.AugmentedDot: 
                            if (j == target.Length) 
                            {
                                match[i++] = j; 
                            }
                            else if (target[j] == '.')
                            {
                                match[i++] = ++j; 
                            }
                            else 
                            { 
                                reverse = true;
                            } 
                            continue;

                        case ShExpTokens.AugmentedAsterisk:
                            if (j == target.Length || target[j] == '.') 
                            {
                                reverse = true; 
                            } 
                            else
                            { 
                                match[i++] = ++j;
                            }
                            continue;
 
                        case ShExpTokens.AugmentedQuestion:
                            if (j == target.Length || target[j] == '.') 
                            { 
                                match[i++] = j;
                            } 
                            else
                            {
                                match[i++] = ++j;
                            } 
                            continue;
 
                        case ShExpTokens.Start: 
                            if (j != 0)
                            { 
                                break;
                            }
                            match[i++] = 0;
                            continue; 

                        case ShExpTokens.End: 
                            if (j == target.Length) 
                            {
                                matched = true; 
                                break;
                            }
                            reverse = true;
                            continue; 

                        default: 
                            if (j < target.Length && (int) pattern[i] == (int) char.ToLowerInvariant(target[j])) 
                            {
                                match[i++] = ++j; 
                            }
                            else
                            {
                                reverse = true; 
                            }
                            continue; 
                    } 
                }
                else 
                {
                    switch (pattern[--i])
                    {
                        case ShExpTokens.Asterisk: 
                        case ShExpTokens.AugmentedQuestion:
                            if (match[i] != match[i - 1]) 
                            { 
                                j = --match[i++];
                                reverse = false; 
                            }
                            continue;

                        case ShExpTokens.Start: 
                        case ShExpTokens.End:
                            break; 
 
                        case ShExpTokens.Question:
                        case ShExpTokens.AugmentedDot: 
                        case ShExpTokens.AugmentedAsterisk:
                        default:
                            continue;
                    } 
                }
                break; 
            } 

            GlobalLog.Print("ShellServices.ShellExpression#" + ValidationHelper.HashString(this) + "::IsMatch() return:" + matched.ToString()); 
            return matched;
        }

        private void Parse(string patString) 
        {
            pattern = new ShExpTokens[patString.Length + 2];  // 2 for the start, end 
            match = null; 
            int i = 0;
 
            pattern[i++] = ShExpTokens.Start;
            for (int j = 0; j < patString.Length; j++)
            {
                switch (patString[j]) 
                {
                    case '?': 
                        pattern[i++] = ShExpTokens.Question; 
                        break;
 
                    case '*':
                        pattern[i++] = ShExpTokens.Asterisk;
                        break;
 
                    case '^':
                        if (j < patString.Length - 1) 
                        { 
                            j++;
                        } 
                        else
                        {
                            pattern = null;
                            if (Logging.On) Logging.PrintWarning(Logging.Web, SR.GetString(SR.net_log_shell_expression_pattern_format_warning, patString)); 
                            throw new FormatException(SR.GetString(SR.net_format_shexp, patString));
                        } 
                        switch (patString[j]) 
                        {
                            case '.': 
                                pattern[i++] = ShExpTokens.AugmentedDot;
                                break;

                            case '?': 
                                pattern[i++] = ShExpTokens.AugmentedQuestion;
                                break; 
 
                            case '*':
                                pattern[i++] = ShExpTokens.AugmentedAsterisk; 
                                break;

                            default:
                                pattern = null; 
                                if (Logging.On) Logging.PrintWarning(Logging.Web, SR.GetString(SR.net_log_shell_expression_pattern_format_warning, patString));
                                throw new FormatException(SR.GetString(SR.net_format_shexp, patString)); 
                        } 
                        break;
 
                    default:
                        pattern[i++] = (ShExpTokens) (int) char.ToLowerInvariant(patString[j]);
                        break;
                } 
            }
 
            pattern[i++] = ShExpTokens.End; 
            match = new int[i];
        } 
    }
}

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