reactos/base/shell/cmd/redir.c

   1 /*
   2  *  REDIR.C - redirection handling.
   3  *
   4  *
   5  *  History:
   6  *
   7  *    12/15/95 (Tim Norman)
   8  *        started.
   9  *
  10  *    12 Jul 98 (Hans B Pufal)
  11  *        Rewrote to make more efficient and to conform to new command.c
  12  *        and batch.c processing.
  13  *
  14  *    27-Jul-1998 (John P Price <linux-guru@gcfl.net>)
  15  *        Added config.h include
  16  *
  17  *    22-Jan-1999 (Eric Kohl)
  18  *        Unicode safe!
  19  *        Added new error redirection "2>" and "2>>".
  20  *
  21  *    26-Jan-1999 (Eric Kohl)
  22  *        Added new error AND output redirection "&>" and "&>>".
  23  *
  24  *    24-Jun-2005 (Brandon Turner <turnerb7@msu.edu>)
  25  *        simple check to fix > and | bug with 'rem'
  26  */
  27
  28 #include <precomp.h>
  29
  30 #ifdef FEATURE_REDIRECTION
  31
  32
  33 /* cmd allows redirection of handles numbered 3-9 even though these don't
  34  * correspond to any STD_ constant. */
  35 static HANDLE ExtraHandles[10 - 3];
  36
  37 static HANDLE GetHandle(UINT Number)
  38 {
  39         if (Number < 3)
  40                 return GetStdHandle(STD_INPUT_HANDLE - Number);
  41         else
  42                 return ExtraHandles[Number - 3];
  43 }
  44
  45 static VOID SetHandle(UINT Number, HANDLE Handle)
  46 {
  47         if (Number < 3)
  48                 SetStdHandle(STD_INPUT_HANDLE - Number, Handle);
  49         else
  50                 ExtraHandles[Number - 3] = Handle;
  51 }
  52
  53 BOOL
  54 PerformRedirection(REDIRECTION *RedirList)
  55 {
  56         REDIRECTION *Redir;
  57         LPTSTR Filename;
  58         HANDLE hNew;
  59         UINT DupNumber;
  60         static SECURITY_ATTRIBUTES SecAttr = { sizeof(SECURITY_ATTRIBUTES), NULL, TRUE };
  61
  62         /* Some parameters used for read, write, and append, respectively */
  63         static const DWORD dwAccess[] = {
  64                 GENERIC_READ,
  65                 GENERIC_WRITE,
  66                 GENERIC_WRITE
  67         };
  68         static const DWORD dwShareMode[] = {
  69                 FILE_SHARE_READ | FILE_SHARE_WRITE,
  70                 FILE_SHARE_READ,
  71                 FILE_SHARE_READ
  72         };
  73         static const DWORD dwCreationDisposition[] = {
  74                 OPEN_EXISTING,
  75                 CREATE_ALWAYS,
  76                 OPEN_ALWAYS
  77         };
  78
  79         for (Redir = RedirList; Redir; Redir = Redir->Next)
  80         {
  81                 Filename = DoDelayedExpansion(Redir->Filename);
  82                 if (!Filename)
  83                         goto redir_error;
  84                 StripQuotes(Filename);
  85
  86                 if (*Filename == _T('&'))
  87                 {
  88                         DupNumber = Filename[1] - _T('0');
  89                         if (DupNumber >= 10 ||
  90                             !DuplicateHandle(GetCurrentProcess(),
  91                                              GetHandle(DupNumber),
  92                                              GetCurrentProcess(),
  93                                              &hNew,
  94                                              0,
  95                                              TRUE,
  96                                              DUPLICATE_SAME_ACCESS))
  97                         {
  98                                 hNew = INVALID_HANDLE_VALUE;
  99                         }
 100                 }
 101                 else
 102                 {
 103                         hNew = CreateFile(Filename,
 104                                           dwAccess[Redir->Type],
 105                                           dwShareMode[Redir->Type],
 106                                           &SecAttr,
 107                                           dwCreationDisposition[Redir->Type],
 108                                           0,
 109                                           NULL);
 110                 }
 111
 112                 if (hNew == INVALID_HANDLE_VALUE)
 113                 {
 114                         ConErrResPrintf(Redir->Type == REDIR_READ ? STRING_CMD_ERROR1 : STRING_CMD_ERROR3,
 115                                         Filename);
 116                         cmd_free(Filename);
 117 redir_error:
 118                         /* Undo all the redirections before this one */
 119                         UndoRedirection(RedirList, Redir);
 120                         return FALSE;
 121                 }
 122
 123                 if (Redir->Type == REDIR_APPEND)
 124                         SetFilePointer(hNew, 0, NULL, FILE_END);
 125                 Redir->OldHandle = GetHandle(Redir->Number);
 126                 SetHandle(Redir->Number, hNew);
 127
 128                 TRACE("%d redirected to: %s\n", Redir->Number, debugstr_aw(Filename));
 129                 cmd_free(Filename);
 130         }
 131         return TRUE;
 132 }
 133
 134 VOID
 135 UndoRedirection(REDIRECTION *Redir, REDIRECTION *End)
 136 {
 137         for (; Redir != End; Redir = Redir->Next)
 138         {
 139                 CloseHandle(GetHandle(Redir->Number));
 140                 SetHandle(Redir->Number, Redir->OldHandle);
 141                 Redir->OldHandle = INVALID_HANDLE_VALUE;
 142         }
 143 }
 144
 145 VOID
 146 FreeRedirection(REDIRECTION *Redir)
 147 {
 148         REDIRECTION *Next;
 149         for (; Redir; Redir = Next)
 150         {
 151                 Next = Redir->Next;
 152                 ASSERT(Redir->OldHandle == INVALID_HANDLE_VALUE);
 153                 cmd_free(Redir);
 154         }
 155 }
 156
 157 #endif /* FEATURE_REDIRECTION */