Mac – How to install getent on Snow Leopard

macmacportssnow leopard

I have several scripts which require the utility getent. In addition, I've read several handy tips which use getent.

getent is a Networking utility which is widely available on Unix, *BSD and Linux-based systems. This tool is commonly used by Sysadmins and power users to lookup network information (IP addresses, etc). As far as hostnames go, getent is one of the few tools which use both /etc/hosts and DNS.

As Wikipedia says:

getent is a unix command that helps a user get entries in a number of
important text files called databases.

The important thing here is that getent will search the same name services in the same order as would most applications on a unix-like system. This makes it invaluable when debugging system or application trouble.
Tools like dig and nslookup specifically look at DNS only, while dscl expects you to spell out the name services you want to search.

I would like to use getent for two testcases:

  1. Parse /etc/hosts before querying DNS. For example, if I add testhost.example.org to /etc/hosts, then getent hosts testhost.example.org should use the entry from /etc/hosts before querying DNS.

  2. Query LDAP using getent

MacPorts does not seem to provide a package providing getent.

Does getent exist on Snow Leopard?

Best Answer

dscacheutil is probably the best way to do this. It doesn't emulate the usual search process, it uses it, so you'll actually get the same results as a standard lookup (including caching, /etc/hosts, computer records in directory services, DNS, mDNS for .local names, etc).

$ dscacheutil -q host -a name www.apple.com
name: e3191.c.akamaiedge.net
alias: www.apple.com www.isg-apple.com.akadns.net www.apple.com.edgekey.net 
ip_address: 69.192.45.15

$ dscacheutil -q host -a name gordons-mbp.local
name: gordons-mbp.local
ipv6_address: fe80:5::e6ce:8fff:fe50:136

name: gordons-mbp.local
ip_address: 192.168.10.249

$ dscacheutil -q host -a ip_address 127.0.0.1
name: localhost
alias: 1.0.0.127.in-addr.arpa 
ip_address: 127.0.0.1

$ dscacheutil -q user -a name gordon
name: gordon
password: ********
uid: 501
gid: 20
dir: /Users/gordon
shell: /bin/bash
gecos: Gordon Davisson
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