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.Runtime.CompilerServices;
   7 using System.Text;
   8
   9 namespace System
  10 {
  11     internal static partial class PasteArguments
  12     {
  13          /// <summary>
  14         /// Repastes a set of arguments into a linear string that parses back into the originals under pre- or post-2008 VC parsing rules.
  15         /// The rules for parsing the executable name (argv[0]) are special, so you must indicate whether the first argument actually is argv[0].
  16         /// </summary>
  17         internal static string Paste(IEnumerable<string> arguments, bool pasteFirstArgumentUsingArgV0Rules)
  18         {
  19             var stringBuilder = new StringBuilder();
  20
  21             foreach (string argument in arguments)
  22             {
  23                 if (pasteFirstArgumentUsingArgV0Rules)
  24                 {
  25                     pasteFirstArgumentUsingArgV0Rules = false;
  26
  27                     // Special rules for argv[0]
  28                     //   - Backslash is a normal character.
  29                     //   - Quotes used to include whitespace characters.
  30                     //   - Parsing ends at first whitespace outside quoted region.
  31                     //   - No way to get a literal quote past the parser.
  32
  33                     bool hasWhitespace = false;
  34                     foreach (char c in argument)
  35                     {
  36                         if (c == Quote)
  37                         {
  38                             throw new ApplicationException("The argv[0] argument cannot include a double quote.");
  39                         }
  40                         if (char.IsWhiteSpace(c))
  41                         {
  42                             hasWhitespace = true;
  43                         }
  44                     }
  45                     if (argument.Length == 0 || hasWhitespace)
  46                     {
  47                         stringBuilder.Append(Quote);
  48                         stringBuilder.Append(argument);
  49                         stringBuilder.Append(Quote);
  50                     }
  51                     else
  52                     {
  53                         stringBuilder.Append(argument);
  54                     }
  55                 }
  56                 else
  57                 {
  58                     AppendArgument(stringBuilder, argument);
  59                 }
  60             }
  61
  62             return stringBuilder.ToString();
  63         }
  64
  65     }
  66 }