subsys/system/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  *        Seperated 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 <ekohl@abo.rhein-zeitung.de>)
  17  *        Added help text ("if /?") and cleaned up.
  18  *
  19  *    21-Jan-1999 (Eric Kohl <ekohl@abo.rhein-zeitung.de>)
  20  *        Unicode and redirection ready!
  21  *
  22  *    01-Sep-1999 (Eric Kohl <ekohl@abo.rhein-zeitung.de>)
  23  *        Fixed help text.
  24  *
  25  *    17-Feb-2001 (ea)
  26  *        IF DEFINED variable command
  27  */
  28
  29 #include "config.h"
  30
  31 #include <windows.h>
  32 #include <tchar.h>
  33 #include <string.h>
  34 #include <ctype.h>
  35
  36 #include "cmd.h"
  37 #include "batch.h"
  38
  39
  40 #define X_EXEC 1
  41 #define X_EMPTY 0x80
  42
  43 INT cmd_if (LPTSTR cmd, LPTSTR param)
  44 {
  45         INT x_flag = 0; /* when set cause 'then' clause to be executed */
  46         LPTSTR pp;
  47
  48 #ifdef _DEBUG
  49         DebugPrintf ("cmd_if: (\'%s\', \'%s\'\n", cmd, param);
  50 #endif
  51
  52         if (!_tcsncmp (param, _T("/?"), 2))
  53         {
  54                 ConOutPuts (_T("Performs conditional processing in batch programs.\n"
  55                                "\n"
  56                                "  IF [NOT] ERRORLEVEL number command\n"
  57                                "  IF [NOT] string1==string2 command\n"
  58                                "  IF [NOT] EXIST filename command\n"
  59                                "  IF [NOT] DEFINED variable command\n"
  60                                "\n"
  61                                "NOT               Specifies that CMD should carry out the command only if\n"
  62                                "                  the condition is false\n"
  63                                "ERRORLEVEL number Specifies a true condition if the last program run returned\n"
  64                                "                  an exit code equal or greater than the number specified.\n"
  65                                "command           Specifies the command to carry out if the condition is met.\n"
  66                                "string1==string2  Specifies a true condition if the specified text strings\n"
  67                                "                  match.\n"
  68                                "EXIST filename    Specifies a true condition if the specified filename exists.\n"
  69                                "DEFINED variable  Specifies a true condition if the specified variable is\n"
  70                                "                  defined."));
  71                 return 0;
  72         }
  73
  74         /* First check if param string begins with word 'not' */
  75         if (!_tcsnicmp (param, _T("not"), 3) && _istspace (*(param + 3)))
  76         {
  77                 x_flag = X_EXEC;            /* Remember 'NOT' */
  78                 param += 3;                 /* Step over 'NOT' */
  79                 while (_istspace (*param))  /* And subsequent spaces */
  80                         param++;
  81         }
  82
  83         /* Check for 'exist' form */
  84         if (!_tcsnicmp (param, _T("exist"), 5) && _istspace (*(param + 5)))
  85         {
  86                 param += 5;
  87                 while (_istspace (*param))
  88                         param++;
  89
  90                 pp = param;
  91                 while (*pp && !_istspace (*pp))
  92                         pp++;
  93
  94                 if (*pp)
  95                 {
  96                         WIN32_FIND_DATA f;
  97                         HANDLE hFind;
  98
  99                         *pp++ = _T('\0');
 100                         hFind = FindFirstFile (param, &f);
 101                         x_flag ^= (hFind == INVALID_HANDLE_VALUE) ? 0 : X_EXEC;
 102                         if (hFind != INVALID_HANDLE_VALUE)
 103                         {
 104                                 FindClose (hFind);
 105                         }
 106                 }
 107                 else
 108                         return 0;
 109         }
 110
 111         /* Check for 'defined' form */
 112         else if (!_tcsnicmp (param, _T("defined"), 7) && _istspace (*(param + 7)))
 113         {
 114                 TCHAR Value [1];
 115                 INT   ValueSize = 0;
 116
 117                 param += 7;
 118                 /* IF [NOT] DEFINED var COMMAND */
 119                 /*                 ^            */
 120                 while (_istspace (*param))
 121                         param++;
 122                 /* IF [NOT] DEFINED var COMMAND */
 123                 /*                  ^           */
 124                 pp = param;
 125                 while (*pp && !_istspace (*pp))
 126                         pp++;
 127                 /* IF [NOT] DEFINED var COMMAND */
 128                 /*                     ^        */
 129                 if (*pp)
 130                 {
 131                         *pp++ = _T('\0');
 132                         ValueSize = GetEnvironmentVariable(param, Value, sizeof Value);
 133                         x_flag ^= (0 == ValueSize)
 134                                         ? 0
 135                                         : X_EXEC;
 136                         x_flag |= X_EMPTY;
 137                 }
 138                 else
 139                         return 0;
 140         }
 141
 142         /* Check for 'errorlevel' form */
 143         else if (!_tcsnicmp (param, _T("errorlevel"), 10) && _istspace (*(param + 10)))
 144         {
 145                 INT n = 0;
 146
 147                 pp = param + 10;
 148                 while (_istspace (*pp))
 149                         pp++;
 150
 151                 while (_istdigit (*pp))
 152                         n = n * 10 + (*pp++ - _T('0'));
 153
 154                 x_flag ^= (nErrorLevel < n) ? 0 : X_EXEC;
 155
 156                 x_flag |= X_EMPTY;          /* Syntax error if comd empty */
 157         }
 158
 159         /* Check that '==' is present, syntax error if not */
 160         else if (NULL == (pp = _tcsstr (param, _T("=="))))
 161         {
 162                 error_syntax (NULL);
 163                 return 1;
 164         }
 165
 166         else
 167         {
 168                 /* Change first '='to space to terminate comparison loop */
 169
 170                 *pp = _T(' ');   /* Need a space to terminate comparison loop */
 171                 pp += 2;                /* over '==' */
 172                 while (_istspace (*pp)) /* Skip subsequent spaces */
 173                         pp++;
 174
 175                 _tcscat (pp, _T(" "));  /* Add one space to ensure comparison ends */
 176
 177                 while (*param == *pp)       /* Comparison loop */
 178                 {
 179                         if (_istspace (*param))      /* Terminates on space */
 180                                 break;
 181
 182                         param++, pp++;
 183                 }
 184
 185                 if (x_flag ^= (*param != *pp) ? 0 : X_EXEC)
 186                 {
 187                         while (*pp && !_istspace (*pp))  /* Find first space, */
 188                                 pp++;
 189
 190                         x_flag |= X_EMPTY;
 191                 }
 192         }
 193
 194         if (x_flag & X_EMPTY)
 195         {
 196                 while (_istspace (*pp)) /* Then skip spaces */
 197                         pp++;
 198
 199                 if (*pp == _T('\0'))    /* If nothing left then syntax err */
 200                 {
 201                         error_syntax (NULL);
 202                         return 1;
 203                 }
 204         }
 205
 206         if (x_flag & X_EXEC)
 207         {
 208                 ParseCommandLine (pp);
 209         }
 210
 211         return 0;
 212 }