rosapps/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
  26 #include "config.h"
  27
  28 #include <windows.h>
  29 #include <tchar.h>
  30 #include <string.h>
  31 #include <ctype.h>
  32
  33 #include "cmd.h"
  34 #include "batch.h"
  35
  36
  37 #define X_EXEC 1
  38 #define X_EMPTY 0x80
  39
  40
  41 INT cmd_if (LPTSTR cmd, LPTSTR param)
  42 {
  43         INT x_flag = 0; /* when set cause 'then' clause to be executed */
  44         LPTSTR pp;
  45
  46 #ifdef _DEBUG
  47         DebugPrintf ("cmd_if: (\'%s\', \'%s\'\n", cmd, param);
  48 #endif
  49
  50         if (!_tcsncmp (param, _T("/?"), 2))
  51         {
  52                 ConOutPuts (_T("Performs conditional processing in batch programs.\n"
  53                                "\n"
  54                                "  IF [NOT] ERRORLEVEL number command\n"
  55                                "  IF [NOT] string1==string2 command\n"
  56                                "  IF [NOT] EXIST filename command\n"
  57                                "\n"
  58                                "NOT               Specifies that CMD should carry out the command only if\n"
  59                                "                  the condition is false\n"
  60                                "ERRORLEVEL number Specifies a true condition if the last program run returned\n"
  61                                "                  an exit code equal or greater than the number specified.\n"
  62                                "command           Specifies the command to carry out if the condition is met.\n"
  63                                "string1==string2  Specifies a true condition if the specified text strings\n"
  64                                "                  match.\n"
  65                                "EXIST filename    Specifies a true condition if the specified filename exists."));
  66                 return 0;
  67         }
  68
  69         /* First check if param string begins with word 'not' */
  70         if (!_tcsnicmp (param, _T("not"), 3) && _istspace (*(param + 3)))
  71         {
  72                 x_flag = X_EXEC;            /* Remember 'NOT' */
  73                 param += 3;                 /* Step over 'NOT' */
  74                 while (_istspace (*param))  /* And subsequent spaces */
  75                         param++;
  76         }
  77
  78         /* Check for 'exist' form */
  79         if (!_tcsnicmp (param, _T("exist"), 5) && _istspace (*(param + 5)))
  80         {
  81                 param += 5;
  82                 while (_istspace (*param))
  83                         param++;
  84
  85                 pp = param;
  86                 while (*pp && !_istspace (*pp))
  87                         pp++;
  88
  89                 if (*pp)
  90                 {
  91                         WIN32_FIND_DATA f;
  92                         HANDLE hFind;
  93
  94                         *pp++ = _T('\0');
  95                         hFind = FindFirstFile (param, &f);
  96                         x_flag ^= (hFind != INVALID_HANDLE_VALUE) ? 0 : X_EXEC;
  97                         if (hFind != INVALID_HANDLE_VALUE)
  98                                 FindClose (hFind);
  99                 }
 100                 else
 101                         return 0;
 102         }
 103
 104         /* Check for 'errorlevel' form */
 105         else if (!_tcsnicmp (param, _T("errorlevel"), 10) && _istspace (*(param + 10)))
 106         {
 107                 INT n = 0;
 108
 109                 pp = param + 10;
 110                 while (_istspace (*pp))
 111                         pp++;
 112
 113                 while (_istdigit (*pp))
 114                         n = n * 10 + (*pp++ - _T('0'));
 115
 116                 x_flag ^= (nErrorLevel < n) ? 0 : X_EXEC;
 117
 118                 x_flag |= X_EMPTY;          /* Syntax error if comd empty */
 119         }
 120
 121         /* Check that '==' is present, syntax error if not */
 122         else if (NULL == (pp = _tcsstr (param, _T("=="))))
 123         {
 124                 error_syntax (NULL);
 125                 return 1;
 126         }
 127
 128         else
 129         {
 130                 /* Change first '='to space to terminate comparison loop */
 131
 132                 *pp = _T(' ');   /* Need a space to terminate comparison loop */
 133                 pp += 2;                /* over '==' */
 134                 while (_istspace (*pp)) /* Skip subsequent spaces */
 135                         pp++;
 136
 137                 _tcscat (pp, _T(" "));  /* Add one space to ensure comparison ends */
 138
 139                 while (*param == *pp)       /* Comparison loop */
 140                 {
 141                         if (_istspace (*param))      /* Terminates on space */
 142                                 break;
 143
 144                         param++, pp++;
 145                 }
 146
 147                 if (x_flag ^= (*param != *pp) ? 0 : X_EXEC)
 148                 {
 149                         while (*pp && !_istspace (*pp))  /* Find first space, */
 150                                 pp++;
 151
 152                         x_flag |= X_EMPTY;
 153                 }
 154         }
 155
 156         if (x_flag & X_EMPTY)
 157         {
 158                 while (_istspace (*pp)) /* Then skip spaces */
 159                         pp++;
 160
 161                 if (*pp == _T('\0'))    /* If nothing left then syntax err */
 162                 {
 163                         error_syntax (NULL);
 164                         return 1;
 165                 }
 166         }
 167
 168         if (x_flag & X_EXEC)
 169                 ParseCommandLine (pp);
 170
 171         return 0;
 172 }