base/shell/cmd/dirstack.c

   1 /*
   2  *  DIRSTACK.C - pushd / pop (directory stack) internal commands.
   3  *
   4  *
   5  *  History:
   6  *
   7  *    14-Dec-1998 (Eric Kohl)
   8  *        Implemented PUSHD and POPD command.
   9  *
  10  *    20-Jan-1999 (Eric Kohl)
  11  *        Unicode and redirection safe!
  12  *
  13  *    20-Jan-1999 (Eric Kohl)
  14  *        Added DIRS command.
  15  */
  16
  17 #include "precomp.h"
  18
  19 #ifdef FEATURE_DIRECTORY_STACK
  20
  21 typedef struct tagDIRENTRY
  22 {
  23     struct tagDIRENTRY *prev;
  24     struct tagDIRENTRY *next;
  25     TCHAR szPath[1];
  26 } DIRENTRY, *LPDIRENTRY;
  27
  28
  29 static INT nStackDepth;
  30 static LPDIRENTRY lpStackTop;
  31 static LPDIRENTRY lpStackBottom;
  32
  33
  34 static INT
  35 PushDirectory (LPTSTR pszPath)
  36 {
  37     LPDIRENTRY lpDir = cmd_alloc(FIELD_OFFSET(DIRENTRY, szPath[_tcslen(pszPath) + 1]));
  38     if (!lpDir)
  39     {
  40         error_out_of_memory ();
  41         return -1;
  42     }
  43
  44     lpDir->prev = NULL;
  45     lpDir->next = lpStackTop;
  46     if (lpStackTop == NULL)
  47         lpStackBottom = lpDir;
  48     else
  49         lpStackTop->prev = lpDir;
  50     lpStackTop = lpDir;
  51
  52     _tcscpy(lpDir->szPath, pszPath);
  53
  54     nStackDepth++;
  55
  56     return nErrorLevel = 0;
  57 }
  58
  59
  60 static VOID
  61 PopDirectory (VOID)
  62 {
  63     LPDIRENTRY lpDir = lpStackTop;
  64     lpStackTop = lpDir->next;
  65     if (lpStackTop != NULL)
  66         lpStackTop->prev = NULL;
  67     else
  68         lpStackBottom = NULL;
  69
  70     cmd_free (lpDir);
  71
  72     nStackDepth--;
  73 }
  74
  75
  76 /*
  77  * initialize directory stack
  78  */
  79 VOID InitDirectoryStack (VOID)
  80 {
  81     nStackDepth = 0;
  82     lpStackTop = NULL;
  83     lpStackBottom = NULL;
  84 }
  85
  86
  87 /*
  88  * destroy directory stack
  89  */
  90 VOID DestroyDirectoryStack (VOID)
  91 {
  92     while (nStackDepth)
  93         PopDirectory ();
  94 }
  95
  96
  97 INT GetDirectoryStackDepth (VOID)
  98 {
  99     return nStackDepth;
 100 }
 101
 102
 103 /*
 104  * pushd command
 105  */
 106 INT CommandPushd (LPTSTR rest)
 107 {
 108     TCHAR curPath[MAX_PATH];
 109
 110     if (!_tcsncmp (rest, _T("/?"), 2))
 111     {
 112         ConOutResPuts(STRING_DIRSTACK_HELP1);
 113         return 0;
 114     }
 115
 116     GetCurrentDirectory (MAX_PATH, curPath);
 117
 118     if (rest[0] != _T('\0'))
 119     {
 120         if (!SetRootPath(NULL, rest))
 121             return 1;
 122     }
 123
 124     return PushDirectory(curPath);
 125 }
 126
 127
 128 /*
 129  * popd command
 130  */
 131 INT CommandPopd (LPTSTR rest)
 132 {
 133     INT ret = 0;
 134     if (!_tcsncmp(rest, _T("/?"), 2))
 135     {
 136         ConOutResPuts(STRING_DIRSTACK_HELP2);
 137         return 0;
 138     }
 139
 140     if (nStackDepth == 0)
 141         return 1;
 142
 143     ret = _tchdir(lpStackTop->szPath) != 0;
 144     PopDirectory ();
 145
 146     return ret;
 147 }
 148
 149
 150 /*
 151  * dirs command
 152  */
 153 INT CommandDirs (LPTSTR rest)
 154 {
 155     LPDIRENTRY lpDir;
 156
 157     if (!_tcsncmp(rest, _T("/?"), 2))
 158     {
 159         ConOutResPuts(STRING_DIRSTACK_HELP3);
 160         return 0;
 161     }
 162
 163     nErrorLevel = 0;
 164
 165     lpDir = lpStackBottom;
 166
 167     if (lpDir == NULL)
 168     {
 169         ConOutResPuts(STRING_DIRSTACK_HELP4);
 170         return 0;
 171     }
 172
 173     while (lpDir != NULL)
 174     {
 175         ConOutPuts(lpDir->szPath);
 176         lpDir = lpDir->prev;
 177     }
 178
 179     return 0;
 180 }
 181
 182 #endif /* FEATURE_DIRECTORY_STACK */