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
  61     static SECURITY_ATTRIBUTES SecAttr = { sizeof(SECURITY_ATTRIBUTES), NULL, TRUE };
  62
  63     /* Some parameters used for read, write, and append, respectively */
  64     static struct REDIR_PARAMS
  65     {
  66         DWORD dwDesiredAccess;
  67         DWORD dwShareMode;
  68         DWORD dwCreationDisposition;
  69     } RedirParams[] =
  70     {
  71         {GENERIC_READ , FILE_SHARE_READ | FILE_SHARE_WRITE, OPEN_EXISTING}, // REDIR_READ
  72         {GENERIC_WRITE, FILE_SHARE_READ                   , CREATE_ALWAYS}, // REDIR_WRITE
  73         {GENERIC_WRITE, FILE_SHARE_READ                   , OPEN_ALWAYS  }  // REDIR_APPEND
  74     };
  75
  76     for (Redir = RedirList; Redir; Redir = Redir->Next)
  77     {
  78         Filename = DoDelayedExpansion(Redir->Filename);
  79         if (!Filename)
  80             goto redir_error;
  81         StripQuotes(Filename);
  82
  83         if (*Filename == _T('&'))
  84         {
  85             DupNumber = Filename[1] - _T('0');
  86             if (DupNumber >= 10 ||
  87                 !DuplicateHandle(GetCurrentProcess(),
  88                                  GetHandle(DupNumber),
  89                                  GetCurrentProcess(),
  90                                  &hNew,
  91                                  0,
  92                                  TRUE,
  93                                  DUPLICATE_SAME_ACCESS))
  94             {
  95                 hNew = INVALID_HANDLE_VALUE;
  96             }
  97         }
  98         else
  99         {
 100             hNew = CreateFile(Filename,
 101                               RedirParams[Redir->Mode].dwDesiredAccess,
 102                               RedirParams[Redir->Mode].dwShareMode,
 103                               &SecAttr,
 104                               RedirParams[Redir->Mode].dwCreationDisposition,
 105                               0,
 106                               NULL);
 107         }
 108
 109         if (hNew == INVALID_HANDLE_VALUE)
 110         {
 111             /* TODO: Print a more detailed message */
 112             ConErrResPrintf(Redir->Mode == REDIR_READ ? STRING_CMD_ERROR1 : STRING_CMD_ERROR3,
 113                             Filename);
 114             cmd_free(Filename);
 115 redir_error:
 116             /* Undo all the redirections before this one */
 117             UndoRedirection(RedirList, Redir);
 118             return FALSE;
 119         }
 120
 121         if (Redir->Mode == REDIR_APPEND)
 122             SetFilePointer(hNew, 0, NULL, FILE_END);
 123         Redir->OldHandle = GetHandle(Redir->Number);
 124         SetHandle(Redir->Number, hNew);
 125
 126         TRACE("%d redirected to: %s\n", Redir->Number, debugstr_aw(Filename));
 127         cmd_free(Filename);
 128     }
 129     return TRUE;
 130 }
 131
 132 VOID
 133 UndoRedirection(REDIRECTION *Redir, REDIRECTION *End)
 134 {
 135     for (; Redir != End; Redir = Redir->Next)
 136     {
 137         CloseHandle(GetHandle(Redir->Number));
 138         SetHandle(Redir->Number, Redir->OldHandle);
 139         Redir->OldHandle = INVALID_HANDLE_VALUE;
 140     }
 141 }
 142
 143 VOID
 144 FreeRedirection(REDIRECTION *Redir)
 145 {
 146     REDIRECTION *Next;
 147     for (; Redir; Redir = Next)
 148     {
 149         Next = Redir->Next;
 150         ASSERT(Redir->OldHandle == INVALID_HANDLE_VALUE);
 151         cmd_free(Redir);
 152     }
 153 }
 154
 155 #endif /* FEATURE_REDIRECTION */