netcore/System.Private.CoreLib/shared/System/PasteArguments.Windows.cs

   1 // Licensed to the .NET Foundation under one or more agreements.
   2 // The .NET Foundation licenses this file to you under the MIT license.
   3 // See the LICENSE file in the project root for more information.
   4
   5 using System.Collections.Generic;
   6 using System.Text;
   7
   8 namespace System
   9 {
  10     internal static partial class PasteArguments
  11     {
  12         /// <summary>
  13         /// Repastes a set of arguments into a linear string that parses back into the originals under pre- or post-2008 VC parsing rules.
  14         /// The rules for parsing the executable name (argv[0]) are special, so you must indicate whether the first argument actually is argv[0].
  15         /// </summary>
  16         internal static string Paste(IEnumerable<string> arguments, bool pasteFirstArgumentUsingArgV0Rules)
  17         {
  18             var stringBuilder = new StringBuilder();
  19
  20             foreach (string argument in arguments)
  21             {
  22                 if (pasteFirstArgumentUsingArgV0Rules)
  23                 {
  24                     pasteFirstArgumentUsingArgV0Rules = false;
  25
  26                     // Special rules for argv[0]
  27                     //   - Backslash is a normal character.
  28                     //   - Quotes used to include whitespace characters.
  29                     //   - Parsing ends at first whitespace outside quoted region.
  30                     //   - No way to get a literal quote past the parser.
  31
  32                     bool hasWhitespace = false;
  33                     foreach (char c in argument)
  34                     {
  35                         if (c == Quote)
  36                         {
  37                             throw new ApplicationException("The argv[0] argument cannot include a double quote.");
  38                         }
  39                         if (char.IsWhiteSpace(c))
  40                         {
  41                             hasWhitespace = true;
  42                         }
  43                     }
  44                     if (argument.Length == 0 || hasWhitespace)
  45                     {
  46                         stringBuilder.Append(Quote);
  47                         stringBuilder.Append(argument);
  48                         stringBuilder.Append(Quote);
  49                     }
  50                     else
  51                     {
  52                         stringBuilder.Append(argument);
  53                     }
  54                 }
  55                 else
  56                 {
  57                     AppendArgument(stringBuilder, argument);
  58                 }
  59             }
  60
  61             return stringBuilder.ToString();
  62         }
  63     }
  64 }