Search for entry in Hosts file

Keywords:   Search for entry in Hosts file 

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Question:

Need to remove an entry in the hosts file on workstations. e.g. "127.0.0.1 localhost" How to search for the above entry in the hosts file and if it present, remove it.

Answer:

NB: You generally need admin access to update the hosts file (on NT/2000/XP).

;autoupdate hosts file.

;Removehost udf that does the hard work
#DefineFunction RemoveHost(bb,hostname)
	ptr=BinaryIndexEx(bb,0,hostname,@FWDSCAN,@FALSE)
	If ptr==-1 Then Return(0)
	
	;found one.  find beginning of line
	ptra=BinaryIndexEx(bb,ptr,@LF,@BACKSCAN,@TRUE)
	If ptra == -1 Then ptra=0
	Else ptra=ptra+1
	
	;find end of line
	ptrb=BinaryIndexEx(bb,ptr,@LF,@FWDSCAN,@TRUE)
	If ptrb==-1 Then ptrb=BinaryEodGet(bb)-1
	Else ptrb=ptrb+1
	
	
	;Move data
	
	BinaryCopy(bb,ptra,bb,ptrb,BinaryEodGet(bb)-ptrb)
	
	;Set new EOD
	BinaryEodSet(bb,BinaryEodGet(bb)-(ptrb-ptra))
	Return (1)

#EndFunction





;Determine HOSTS file location
;Windows 95/98/Me c:\windows\hosts 
;Windows NT/2000/XP Pro  c:\winnt\system32\drivers\etc\hosts 
;Windows XP Home c:\windows\system32\drivers\etc\hosts 

If WinVersion(4)==4 ; NT family
   HOSTS=StrCat(DirWindows(1),"drivers\etc\hosts")
Else
   HOSTS=StrCat(DirWindows(0),"hosts")
EndIf

;Message("Debug - hosts file name",hosts)

fs=FileSize(hosts)
bb=BinaryAlloc(fs)
BinaryRead(bb,hosts)

;locate removeme

RemoveHost(bb,"hjem.get2net.dk")
RemoveHost(bb,"hjeq.get2net.dk")
RemoveHost(bb,"www.abc.com")
RemoveHost(bb,"www.def.net")

ErrorMode(@OFF)
byteswritten=BinaryWrite(bb,hosts)
ErrorMode(@CANCEL)

BinaryFree(bb)


If byteswritten==0
   Message("Error","Could not write to hosts file")
Else
   Message("Hosts file update","Complete")
EndIf