rom/dos/deletevar.c

   1 /*
   2     Copyright © 1995-2016, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: DeleteVar() - Deletes a local or environmental variable.
   6     Lang: english
   7 */
   8 #include "dos_intern.h"
   9 #include <proto/exec.h>
  10
  11 /*****************************************************************************
  12
  13     NAME */
  14 #include <dos/var.h>
  15 #include <proto/dos.h>
  16
  17         AROS_LH2(LONG, DeleteVar,
  18
  19 /*  SYNOPSIS */
  20         AROS_LHA(CONST_STRPTR, name, D1),
  21         AROS_LHA(ULONG, flags, D2),
  22
  23 /*  LOCATION */
  24         struct DosLibrary *, DOSBase, 152, Dos)
  25
  26 /*  FUNCTION
  27         Deletes a local or environment variable.
  28
  29         The default is to delete a local variable if one was found,
  30         or to delete a global environment variable otherwise.
  31
  32         A global environment variable will only be deleted for the
  33         type LV_VAR.
  34
  35     INPUTS
  36         name  - the name of the variable to delete. Note that variable
  37                 names follow the same syntax and semantics as filesystem
  38                 names.
  39
  40         flags - A combination of the type of variable (low 8 bits), and
  41                 flags to control the behaviour of this routine.
  42                 Currently defined flags:
  43
  44                 GVF_LOCAL_ONLY  - delete a local variable.
  45                 GVF_GLOBAL_ONLY - delete a global environment variable.
  46                 GVF_SAVE_VAR    - delete a global variable permanently.
  47
  48     RESULT
  49         If non-zero, the variable was deleted successfully,
  50         DOSFALSE otherwise.
  51
  52     NOTES
  53         When the GVF_SAVE_VAR flag is set, and only one of the global
  54         variable pair could be deleted (either the in memory or on disk
  55         variable), DOSFALSE will be returned.
  56
  57     EXAMPLE
  58
  59     BUGS
  60
  61     SEE ALSO
  62
  63     INTERNALS
  64
  65 *****************************************************************************/
  66 {
  67   AROS_LIBFUNC_INIT
  68
  69   if(name)
  70   {
  71     if((flags & GVF_GLOBAL_ONLY) == 0)
  72     {
  73       struct LocalVar *lv = NULL;
  74       lv = FindVar(name, flags & 0xFF);
  75       if(lv)
  76       {
  77         /* free allocated memory for value of variable */
  78         FreeMem(lv -> lv_Value, lv -> lv_Len);
  79
  80         Remove((struct Node *)lv);
  81         FreeVec(lv);
  82         return DOSTRUE;
  83       }
  84     } /* !global only => local variable */
  85
  86     /* If we are allowed to delete globals, and not deleting an alias */
  87     if( ((flags & GVF_LOCAL_ONLY) == 0) && ((flags & 0x7F) == 0) )
  88     {
  89       /* Variable names should be less than 256 characters. */
  90       /* as a standard: look for the file in ENV: if no path is
  91          given in the variable
  92       */
  93       UBYTE filebuffer[256] = "ENV:";
  94       BPTR filelock;
  95       BOOL delMemory = FALSE, delDisk = FALSE;
  96
  97       AddPart(filebuffer, name, 256);
  98
  99       if((filelock = Lock(filebuffer, EXCLUSIVE_LOCK)))
 100       {
 101         UnLock(filelock);
 102         delMemory = DeleteFile(filebuffer);
 103       }
 104
 105       if(flags & GVF_SAVE_VAR)
 106       {
 107         filebuffer[0] = 0;
 108         AddPart(filebuffer, "ENVARC:", 256);
 109         AddPart(filebuffer, name, 256);
 110
 111         if((filelock = Lock(filebuffer, EXCLUSIVE_LOCK)))
 112         {
 113           UnLock(filelock);
 114           delDisk = DeleteFile(filebuffer);
 115         }
 116       }
 117       else delDisk = TRUE;
 118
 119       if( (delDisk != FALSE) && (delMemory != FALSE))
 120         return TRUE;
 121     } /* !local only => Global variable */
 122   } /* if(name) */
 123
 124   return DOSFALSE;
 125
 126   AROS_LIBFUNC_EXIT
 127 } /* DeleteVar */