Page 1 of 1
hostname to ip
Posted: Thu Feb 07, 2013 1:06 pm
by FanOfGun
Hi, I need to convert hostname to ip in Linux, how can I do this? Snx in advance.
Re: hostname to ip
Posted: Sat May 11, 2013 11:03 am
by Shardik
The following example code displays all IP addresses belonging to a given host name. I have tested the cross-platform code successfully on these operating systems:
- Kubuntu 12.04 x64 with PB 5.11 x64 in ASCII and Unicode mode
- MacOS X 10.6.8 (Snow Leopard) with PB 5.11 x86 and x64 in ASCII and Unicode mode
- Windows 7 SP1 x64 with PB 5.11 x86 and x64 in ASCII and Unicode mode
Code: Select all
CompilerIf Defined(HOSTENT, #PB_Structure) = #False
Structure hostent
*h_name
*h_aliases
h_addrtype.L
h_length.L
*h_addr_list
EndStructure
CompilerEndIf
InitNetwork()
Procedure GetIPAddressesFromHostname(Hostname.S)
Protected *HostInfos.hostent
Protected *HostnameBuffer
*HostNameBuffer = AllocateMemory(StringByteLength(Hostname, #PB_Ascii))
PokeS(*HostnameBuffer, Hostname, MemorySize(*HostnameBuffer), #PB_Ascii)
*HostInfos = gethostbyname_(*HostnameBuffer)
FreeMemory(*HostnameBuffer)
If *HostInfos = 0
Debug "Error: unable to find host name!"
Else
Debug "Hostname: " + PeekS(*HostInfos\h_name, -1, #PB_Ascii)
If *HostInfos\h_length = 4
IPType = #PB_Network_IPv4
Else
IPType = #PB_Network_IPv6
EndIf
Debug "IP addresses:"
*IP = *HostInfos\h_addr_list
While PeekI(*IP) <> 0
Debug IPString(PeekI(PeekI(*IP)), IPType)
*IP + SizeOf(Integer)
Wend
EndIf
Debug ""
EndProcedure
GetIPAddressesFromHostname("www.google.com")
GetIPAddressesFromHostname("www.purebasic.com")
: I have modified the previous code to also run on Windows.
Re: hostname to ip
Posted: Sat May 11, 2013 2:11 pm
by Bisonte
the function
is crossplatform ???
Re: hostname to ip
Posted: Sat May 11, 2013 2:43 pm
by Shardik
Bisonte wrote:the function
is crossplatform ???
No, it's a Unix API function. But the core of MacOS X is a BSD Unix, therefore most Unix API functions also work for MacOS X...
Re: hostname to ip
Posted: Sat May 11, 2013 2:49 pm
by ts-soft
Shardik wrote:No, it's a Unix API function. But the core of MacOS X is a BSD Unix, therefore most Unix API functions also work for MacOS X...
And it is a windows-API
Re: hostname to ip
Posted: Sat May 11, 2013 3:00 pm
by Shardik
ts-soft wrote:And it is a windows-API
Too slow...
Thomas is right. Before being able to reboot from MacOS into Windows 7 and being able to test, he posted already his remark. When looking up the structure hostent I wondered already why the structure was also described in a MSDN link...
I modified my above code example to also run in Windows without any modification.
Re: hostname to ip
Posted: Sat May 11, 2013 10:02 pm
by Bisonte
I'm impressed
The first API call that does on all OS the same ...
Re: hostname to ip
Posted: Fri Sep 12, 2014 9:19 pm
by blueznl
I could use some help on this one, or perhaps slightly related. I'm updating some old code, and in it I found this:
Code: Select all
buffer_p = AllocateMemory(Len(name)+1)
PokeS(buffer_p,name,-1,#PB_Ascii)
bip_p = gethostbyname_(buffer_p)
FreeMemory(buffer_p)
If bip_p <> 0
ProcedureReturn PeekL(PeekL(PeekL(bip_p+12)))
Else
ProcedureReturn 0
EndIf
I didn't write it myself
and I haven't got a clue where I stole it
Anyway, the above works fine on Win32 but not on Win64. I suspect it's the PeekL stuff...
In other words, how to retrieve the BIP (not the IP) from a name on Win64?
Re: hostname to ip
Posted: Sat Sep 13, 2014 4:30 pm
by Shardik
blueznl wrote:Anyway, the above works fine on Win32 but not on Win64. I suspect it's the PeekL stuff...
In other words, how to retrieve the BIP (not the IP) from a name on Win64?
Your BIP (the result your procedure returns) is the first IP address of the requested host name. In order to work on a 64 bit OS you have to change
Code: Select all
ProcedureReturn PeekL(PeekL(PeekL(bip_p+12)))
to
Code: Select all
ProcedureReturn PeekI(PeekI(PeekI(bip_p+24)))
However I would strongly advice to use the HOSTENT structure so you don't have to care about 32 or 64 bit systems:
Code: Select all
InitNetwork()
Procedure Get1stIPAddressOfHostName(name.S)
buffer_p = AllocateMemory(Len(name)+1)
PokeS(buffer_p,name,-1,#PB_Ascii)
*bip_p.HOSTENT = gethostbyname_(buffer_p)
FreeMemory(buffer_p)
If *bip_p <> 0
ProcedureReturn PeekI(PeekI(*bip_p\h_addr_list))
Else
ProcedureReturn 0
EndIf
EndProcedure
MessageRequester("Info", "1st IP address of www.purebasic.com: " +
IPString(Get1stIPAddressOfHostName("www.purebasic.com"), #PB_Network_IPv4))
Re: hostname to ip
Posted: Sun Sep 14, 2014 2:30 pm
by bbanelli
Bisonte wrote:I'm impressed
The first API call that does on all OS the same ...
Winsock API follows POSIX socket implementation to very high extent, up to some hassle regarding initialization and cleanup.