rom/dos/deletevar.c

   1 /*
   2     Copyright © 1995-2001, 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 environmental variable otherwise.
  31
  32         A global environmental 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 environmental variable.
  46
  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         XXX: Find out whether GVF_SAVE_VAR does actually effect this function.
  65
  66 *****************************************************************************/
  67 {
  68   AROS_LIBFUNC_INIT
  69   AROS_LIBBASE_EXT_DECL(struct DosLibrary *,DOSBase)
  70
  71   if(name)
  72   {
  73     if((flags & GVF_GLOBAL_ONLY) == 0)
  74     {
  75       struct LocalVar *lv = NULL;
  76       lv = FindVar(name, flags & 0xFF);
  77       if(lv)
  78       {
  79         /* free allocated memory for value of variable */
  80         FreeMem(lv -> lv_Value, lv -> lv_Len);
  81
  82         Remove((struct Node *)lv);
  83         FreeVec(lv);
  84         return DOSTRUE;
  85       }
  86     } /* !global only => local variable */
  87
  88     /* If we are allowed to delete globals, and not deleting an alias */
  89     if( ((flags & GVF_LOCAL_ONLY) == 0) && ((flags & 0x7F) == 0) )
  90     {
  91       /* Variable names should be less than 256 characters. */
  92       /* as a standard: look for the file in ENV: if no path is
  93          given in the variable
  94       */
  95       UBYTE filebuffer[256] = "ENV:";
  96       BPTR filelock;
  97       BOOL delMemory = FALSE, delDisk = FALSE;
  98
  99       AddPart(filebuffer, name, 256);
 100
 101       if((filelock = Lock(filebuffer, EXCLUSIVE_LOCK)))
 102       {
 103         UnLock(filelock);
 104         delMemory = DeleteFile(filebuffer);
 105       }
 106
 107       if(flags & GVF_SAVE_VAR)
 108       {
 109         filebuffer[0] = 0;
 110         AddPart(filebuffer, "ENVARC:", 256);
 111         AddPart(filebuffer, name, 256);
 112
 113         if((filelock = Lock(filebuffer, EXCLUSIVE_LOCK)))
 114         {
 115           UnLock(filelock);
 116           delDisk = DeleteFile(filebuffer);
 117         }
 118       }
 119       else delDisk = TRUE;
 120
 121       if( (delDisk != FALSE) && (delMemory != FALSE))
 122         return TRUE;
 123     } /* !local only => Global variable */
 124   } /* if(name) */
 125
 126   return DOSFALSE;
 127
 128   AROS_LIBFUNC_EXIT
 129 } /* DeleteVar */