base/shell/cmd/if.c

   1 /*
   2  *  IF.C - if internal batch command.
   3  *
   4  *
   5  *  History:
   6  *
   7  *    16 Jul 1998 (Hans B Pufal)
   8  *        started.
   9  *
  10  *    16 Jul 1998 (John P Price)
  11  *        Separated commands into individual files.
  12  *
  13  *    27-Jul-1998 (John P Price <linux-guru@gcfl.net>)
  14  *        added config.h include
  15  *
  16  *    07-Jan-1999 (Eric Kohl)
  17  *        Added help text ("if /?") and cleaned up.
  18  *
  19  *    21-Jan-1999 (Eric Kohl)
  20  *        Unicode and redirection ready!
  21  *
  22  *    01-Sep-1999 (Eric Kohl)
  23  *        Fixed help text.
  24  *
  25  *    17-Feb-2001 (ea)
  26  *        IF DEFINED variable command
  27  *
  28  *    28-Apr-2005 (Magnus Olsen) <magnus@greatlord.com>
  29  *        Remove all hardcoded strings in En.rc
  30  *
  31  */
  32
  33 #include "precomp.h"
  34
  35 static INT GenericCmp(INT (*StringCmp)(LPCTSTR, LPCTSTR),
  36                       LPCTSTR Left, LPCTSTR Right)
  37 {
  38     TCHAR *end;
  39     INT nLeft = _tcstol(Left, &end, 0);
  40     if (*end == _T('\0'))
  41     {
  42         INT nRight = _tcstol(Right, &end, 0);
  43         if (*end == _T('\0'))
  44         {
  45             /* both arguments are numeric */
  46             return (nLeft < nRight) ? -1 : (nLeft > nRight);
  47         }
  48     }
  49     return StringCmp(Left, Right);
  50 }
  51
  52 INT cmd_if (LPTSTR param)
  53 {
  54     TRACE ("cmd_if: (\'%s\')\n", debugstr_aw(param));
  55
  56     if (!_tcsncmp (param, _T("/?"), 2))
  57     {
  58         ConOutResPaging(TRUE,STRING_IF_HELP1);
  59         return 0;
  60     }
  61
  62     error_syntax(param);
  63     return 1;
  64 }
  65
  66 INT ExecuteIf(PARSED_COMMAND *Cmd)
  67 {
  68     INT result = FALSE; /* when set cause 'then' clause to be executed */
  69     LPTSTR param;
  70     LPTSTR Left = NULL, Right;
  71
  72     if (Cmd->If.LeftArg)
  73     {
  74         Left = DoDelayedExpansion(Cmd->If.LeftArg);
  75         if (!Left)
  76             return 1;
  77     }
  78     Right = DoDelayedExpansion(Cmd->If.RightArg);
  79     if (!Right)
  80     {
  81         cmd_free(Left);
  82         return 1;
  83     }
  84
  85     if (Cmd->If.Operator == IF_CMDEXTVERSION)
  86     {
  87         /* IF CMDEXTVERSION n: check if Command Extensions version
  88          * is greater or equal to n */
  89         DWORD n = _tcstoul(Right, &param, 10);
  90         if (*param != _T('\0'))
  91         {
  92             error_syntax(Right);
  93             cmd_free(Right);
  94             return 1;
  95         }
  96         result = (2 >= n);
  97     }
  98     else if (Cmd->If.Operator == IF_DEFINED)
  99     {
 100         /* IF DEFINED var: check if environment variable exists */
 101         result = (GetEnvVarOrSpecial(Right) != NULL);
 102     }
 103     else if (Cmd->If.Operator == IF_ERRORLEVEL)
 104     {
 105         /* IF ERRORLEVEL n: check if last exit code is greater or equal to n */
 106         INT n = _tcstol(Right, &param, 10);
 107         if (*param != _T('\0'))
 108         {
 109             error_syntax(Right);
 110             cmd_free(Right);
 111             return 1;
 112         }
 113         result = (nErrorLevel >= n);
 114     }
 115     else if (Cmd->If.Operator == IF_EXIST)
 116     {
 117         BOOL IsDir;
 118         INT Size;
 119         WIN32_FIND_DATA f;
 120         HANDLE hFind;
 121
 122         /* IF EXIST filename: check if file exists (wildcards allowed) */
 123         StripQuotes(Right);
 124
 125         Size = _tcslen(Right);
 126         IsDir = (Right[Size - 1] == '\\');
 127         if (IsDir)
 128             Right[Size - 1] = 0;
 129
 130
 131         hFind = FindFirstFile(Right, &f);
 132         if (hFind != INVALID_HANDLE_VALUE)
 133         {
 134             if (IsDir)
 135             {
 136                 result = ((f.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) == FILE_ATTRIBUTE_DIRECTORY);
 137             }
 138             else
 139             {
 140                 result = TRUE;
 141             }
 142             FindClose(hFind);
 143         }
 144
 145         if (IsDir)
 146             Right[Size - 1] = '\\';
 147     }
 148     else
 149     {
 150         /* Do case-insensitive string comparisons if /I specified */
 151         INT (*StringCmp)(LPCTSTR, LPCTSTR) =
 152             (Cmd->If.Flags & IFFLAG_IGNORECASE) ? _tcsicmp : _tcscmp;
 153
 154         if (Cmd->If.Operator == IF_STRINGEQ)
 155         {
 156             /* IF str1 == str2 */
 157             result = StringCmp(Left, Right) == 0;
 158         }
 159         else
 160         {
 161             result = GenericCmp(StringCmp, Left, Right);
 162             switch (Cmd->If.Operator)
 163             {
 164             case IF_EQU: result = (result == 0); break;
 165             case IF_NEQ: result = (result != 0); break;
 166             case IF_LSS: result = (result < 0); break;
 167             case IF_LEQ: result = (result <= 0); break;
 168             case IF_GTR: result = (result > 0); break;
 169             case IF_GEQ: result = (result >= 0); break;
 170             }
 171         }
 172     }
 173
 174     cmd_free(Left);
 175     cmd_free(Right);
 176
 177     if (result ^ ((Cmd->If.Flags & IFFLAG_NEGATE) != 0))
 178     {
 179         /* full condition was true, do the command */
 180         return ExecuteCommand(Cmd->Subcommands);
 181     }
 182     else
 183     {
 184         /* full condition was false, do the "else" command if there is one */
 185         if (Cmd->Subcommands->Next)
 186             return ExecuteCommand(Cmd->Subcommands->Next);
 187         return 0;
 188     }
 189 }
 190
 191 /* EOF */