mRemoteNG.Tools.ExternalToolArgumentParser.BuildReplacementList C# (CSharp) Method

        private List<Replacement> BuildReplacementList(string input)
        {
            var index = 0;
            var replacements = new List<Replacement>();
            do
            {
                var tokenStart = input.IndexOf("%", index, StringComparison.InvariantCulture);
                if (tokenStart == -1)
                    break;

                var tokenEnd = input.IndexOf("%", tokenStart + 1, StringComparison.InvariantCulture);
                if (tokenEnd == -1)
                    break;

                var tokenLength = tokenEnd - tokenStart + 1;
                var variableNameStart = tokenStart + 1;
                var variableNameLength = tokenLength - 2;
                var isEnvironmentVariable = false;
                var variableName = "";

                if (tokenStart > 0)
                {
                    var tokenStartPrefix = input.Substring(tokenStart - 1, 1).ToCharArray()[0];
                    var tokenEndPrefix = input.Substring(tokenEnd - 1, 1).ToCharArray()[0];

                    if (tokenStartPrefix == '\\' && tokenEndPrefix == '\\')
                    {
                        isEnvironmentVariable = true;

                        // Add the first backslash to the token
                        tokenStart--;
                        tokenLength++;

                        // Remove the last backslash from the name
                        variableNameLength--;
                    }
                    else if (tokenStartPrefix == '^' && tokenEndPrefix == '^')
                    {
                        // Add the first caret to the token
                        tokenStart--;
                        tokenLength++;

                        // Remove the last caret from the name
                        variableNameLength--;

                        variableName = input.Substring(variableNameStart, variableNameLength);
                        replacements.Add(new Replacement(tokenStart, tokenLength, $"%{variableName}%"));

                        index = tokenEnd;
                        continue;
                    }
                }

                var token = input.Substring(tokenStart, tokenLength);

                var escape = DetermineEscapeType(token);

                if (escape != EscapeType.All)
                {
                    // Remove the escape character from the name
                    variableNameStart++;
                    variableNameLength--;
                }

                if (variableNameLength == 0)
                {
                    index = tokenEnd;
                    continue;
                }

                variableName = input.Substring(variableNameStart, variableNameLength);

                var replacementValue = token;
                if (!isEnvironmentVariable)
                {
                    replacementValue = GetVariableReplacement(variableName, token);
                }

                var haveReplacement = false;

                if (replacementValue != token)
                {
                    haveReplacement = true;
                }
                else
                {
                    replacementValue = Environment.GetEnvironmentVariable(variableName);
                    if (replacementValue != null)
                        haveReplacement = true;
                }

                if (haveReplacement)
                {
                    var trailing = tokenEnd + 2 <= input.Length ? input.Substring(tokenEnd + 1, 1).ToCharArray()[0] : '\0';

                    if (escape == EscapeType.All)
                    {
                        replacementValue = CommandLineArguments.EscapeBackslashes(replacementValue);
                        if (trailing == '\'')
                            replacementValue = CommandLineArguments.EscapeBackslashesForTrailingQuote(replacementValue);
                    }

                    if (escape == EscapeType.All || escape == EscapeType.ShellMetacharacters)
                        replacementValue = CommandLineArguments.EscapeShellMetacharacters(replacementValue);

                    replacements.Add(new Replacement(tokenStart, tokenLength, replacementValue));
                    index = tokenEnd + 1;
                }
                else
                {
                    index = tokenEnd;
                }
            } while (true);
            return replacements;
        }