reactos/apps/utils/cmd/where.c

   1 /*
   2  *  WHERE.C - file serch functions.
   3  *
   4  *
   5  *  History:
   6  *
   7  *  07/15/95 (Tim Norman)
   8  *    started.
   9  *
  10  *  08/08/95 (Matt Rains)
  11  *    i have cleaned up the source code. changes now bring this source into
  12  *    guidelines for recommended programming practice.
  13  *
  14  *  12/12/95 (Steffan Kaiser & Tim Norman)
  15  *    added some patches to fix some things and make more efficient
  16  *
  17  *  1/6/96 (Tim Norman)
  18  *    fixed a stupid pointer mistake...  Thanks to everyone who noticed it!
  19  *
  20  *  8/1/96 (Tim Norman)
  21  *    fixed a bug when getenv returns NULL
  22  *
  23  *  8/7/96 (Steffan Kaiser and Tim Norman)
  24  *    speed improvements and bug fixes
  25  *
  26  *  8/27/96 (Tim Norman)
  27  *    changed code to use pointers directly into PATH environment variable
  28  *    rather than making our own copy.  This saves some memory, but requires
  29  *    we write our own function to copy pathnames out of the variable.
  30  *
  31  *  12/23/96 (Aaron Kaufman)
  32  *    Fixed a bug in get_paths() that did not point to the first PATH in the
  33  *    environment variable.
  34  *
  35  *  7/12/97 (Tim Norman)
  36  *    Apparently, Aaron's bugfix got lost, so I fixed it again.
  37  *
  38  *  16 July 1998 (John P. Price)
  39  *    Added stand alone code.
  40  *
  41  *  17 July 1998 (John P. Price)
  42  *    Rewrote find_which to use searchpath function
  43  *
  44  * 24-Jul-1998 (John P Price <linux-guru@gcfl.net>)
  45  * - fixed bug where didn't check all extensions when path was specified
  46  *
  47  * 27-Jul-1998 (John P Price <linux-guru@gcfl.net>)
  48  * - added config.h include
  49  *
  50  * 30-Jul-1998 (John P Price <linux-guru@gcfl.net>)
  51  * - fixed so that it find_which returns NULL if filename is not executable
  52  *   (does not have .bat, .com, or .exe extention). Before command would
  53  *   to execute any file with any extension (opps!)
  54  *
  55  *    03-Dec_1998 (Eric Kohl <ekohl@abo.rhein-zeitung.de>)
  56  *        Changed find_which().
  57  *
  58  *    07-Dec_1998 (Eric Kohl <ekohl@abo.rhein-zeitung.de>)
  59  *        Added ".CMD" extension.
  60  *        Replaced numeric constant by _NR_OF_EXTENSIONS.
  61  */
  62
  63 #define WIN32_LEAN_AND_MEAN
  64
  65 #include "config.h"
  66
  67 #include <windows.h>
  68 #include <string.h>
  69 #include <stdlib.h>
  70
  71 #include "cmd.h"
  72
  73
  74 static LPTSTR ext[]  = {".BAT", ".CMD", ".COM", ".EXE"};
  75 static INT nExtCount = sizeof(ext) / sizeof(LPTSTR);
  76
  77
  78 /* searches for file using path info. */
  79
  80 BOOL find_which (LPCTSTR fname, LPTSTR fullbuffer)
  81 {
  82         static TCHAR temp[MAX_PATH];
  83         LPTSTR fullname;
  84         INT x;
  85
  86         *fullbuffer = _T('\0');
  87
  88         /* if there an extension and it is in the last path component, then
  89          * don't test all the extensions. */
  90         if (!(fullname = _tcsrchr (fname, _T('.'))) ||
  91                 _tcschr (fullname + 1, _T('\\')))
  92         {
  93 #ifdef _DEBUG
  94                 DebugPrintf ("No filename extension!\n");
  95 #endif
  96
  97                 for (x = 0; x < nExtCount; x++)
  98                 {
  99                         _tcscpy (temp, fname);
 100                         _tcscat (temp, ext[x]);
 101 #ifdef _DEBUG
 102                         DebugPrintf ("Checking for %s\n", temp);
 103 #endif
 104                         if (_tcschr (fname, _T('\\')))
 105                         {
 106                                 if (IsValidFileName (temp))
 107                                 {
 108                                         _tcscpy (fullbuffer, temp);
 109                                         return TRUE;
 110                                 }
 111                         }
 112                         else
 113                         {
 114                                 _searchenv (temp, _T("PATH"), fullbuffer);
 115                                 if (*fullbuffer != '\0')
 116                                         return TRUE;
 117                         }
 118                 }
 119         }
 120         else
 121         {
 122                 /* there is an extension... don't test other extensions */
 123                 /* make sure that the extention is one of the four */
 124 #ifdef _DEBUG
 125                 DebugPrintf ("No filename extension!\n");
 126 #endif
 127                 for (x = 0; x < nExtCount; x++)
 128                 {
 129                         if (!_tcsicmp (_tcsrchr (fname, _T('.')), ext[x]))
 130                         {
 131                                 if (_tcschr (fname, _T('\\')))
 132                                 {
 133                                         if (IsValidFileName (fname))
 134                                         {
 135                                                 _tcscpy (fullbuffer, fname);
 136 #ifdef _DEBUG
 137                                                 DebugPrintf ("Found: %s\n", fullbuffer);
 138 #endif
 139                                                 return TRUE;
 140                                         }
 141                                 }
 142                                 else
 143                                 {
 144 #ifdef _DEBUG
 145                                         DebugPrintf ("Checking for %s\n", fname);
 146 #endif
 147                                         _searchenv (fname, _T("PATH"), fullbuffer);
 148                                         if (*fullbuffer != _T('\0'))
 149                                         {
 150 #ifdef _DEBUG
 151                                                 DebugPrintf ("Found: %s\n", fullbuffer);
 152 #endif
 153                                                 return TRUE;
 154                                         }
 155                                 }
 156                         }
 157                 }
 158         }
 159
 160         return FALSE;
 161 }