Domain resolution
lazarus / 38-Networking and Web Programming

----------------------------------------------------------------------
dstritt · 2016-11-29 11:28

Hello, I am attempting to resolve a domain name to a standard IP
address string format, but I am at a loss on how to do this. I
searched the forums but just came up with results referencing units
that don't seem to come with fpc anymore. My program I am working on
now functions fine with dotted ip addresses, but not domain names.

Can someone please help?

Thanks
Daniel

----------------------------------------------------------------------
Leledumbo · 2016-11-29 11:36

This example is compilable and working:
http://svn.freepascal.org/svn/fpc/tags/release_3_0_0/packages/fcl-
net/examples/testdns.pp

----------------------------------------------------------------------
dstritt · 2016-11-29 13:27

testdns.pas(20,6) Fatal: Can't find unit netdb used by testdns

Sorry, I'm kinda new to fpc. Is this unit a 3rd party unit?

----------------------------------------------------------------------
Remy Lebeau · 2016-11-29 20:41

Quote from: dstritt on November 29, 2016, 12:28:15 pmHello, I am
attempting to resolve a domain name to a standard IP address string
format, but I am at a loss on how to do this.

Most platforms support the getaddrinfo() and inet_ntop() functions (or
equivilents) for that purpose.  Pass the domain name to getaddrinfo()
to get a linked list of IP addresses in binary format, and then pass
the binary IPs to inet_ntop() to get their string representations.

----------------------------------------------------------------------
Remy Lebeau · 2016-11-29 20:44

Quote from: dstritt on November 29, 2016, 02:27:43 pmtestdns.pas(20,6)
Fatal: Can't find unit netdb used by testdns

Sorry, I'm kinda new to fpc. Is this unit a 3rd party unit?

No, it is part of the FCL's fcl-net package.

----------------------------------------------------------------------
Leledumbo · 2016-11-30 07:29

Quote from: dstritt on November 29, 2016, 02:27:43 pmtestdns.pas(20,6)
Fatal: Can't find unit netdb used by testdns

Sorry, I'm kinda new to fpc. Is this unit a 3rd party unit?
No, and has been shipped with FPC since 2.2.2. Either your
installation is incomplete or your configuration doesn't cover the
path to that unit directory.