Jim's Web Nook | Software

hostinfo

Here's what's here:

What's New
What It Is
Why To Use It
What's The Catch
Where To Get It
Older Versions

What's New

2000-Jul-20: Version 2.2 released. Added -p/--print option for printing addresses without looking them up. This enables hostinfo to act as a simple converter between dotted-quad, hexadecimal, and backslash-octal IP address formats. Improved handling of syntax errors in command line options (for example).
2000-Jun-14: Version 2.1 released. A few minor but significant changes to the output format. Hosts with multiple IP addresses now display in multiple records, one per address. Added --first-address option, to display only the first address of a host that maps to more than one IP address.

Hostinfo is a utility for looking up hostnames and IP(v4) addresses. Hostinfo uses the gethostbyname(3) and getaddrbyname(3) function calls, which means it tells you what your operating system thinks rather than simply telling you what you already know your DNS server says.

If you don't know what most or all of the above paragraph means, you probably don't need this utility.

Why To Use It

Hostinfo differs from other host-lookup utilities in the following ways:

Some lookup utilities (such as host) are friendly and helpful; unfortunately, their verbose, human-readable output varies depending on their input and makes things more difficult for other programs to parse.
Hostinfo's output is in a succinct, consistent format, easily read and understood by both humans and other programs. Hostinfo also has options for displaying only the information you ask for (hostname, IP address[es], or host aliases) without any frills; hence, it's useful as a shell script utility without having to use awk or some other pattern-matching language.
Many lookup utilities use DNS exclusively to look for hostnames or their corresponding IP addresses. While this is handy for testing DNS servers, it's not as useful for troubleshooting problematic combinations of /etc/hosts, NIS/NIS+, and /etc/resolv.conf.
Hostinfo uses the regular "nethost" function calls for looking up hosts, and hence tells you what your operating system really thinks.
Many lookup utilities display only hostnames and dotted-quad decimal IP addresses.
Hostinfo happily displays IP addresses in hexadecimal or backslash-octal notation if you request it. If you warn hostinfo in advance, it will even try to interpret IP addresses you give to it in hexadecimal or backslash-octal notation as well.

What's The Catch

Hostinfo comes with no documentation other than its extensive, clearly written, superior quality builtin help. There are no building or installation instructions, albeit the accompanying clearly written, easy-to-use Makefile makes building and installing hostinfo from source a snap.

Hostinfo works for me with a wide variety of Linux systems. If it doesn't work for you, consider letting me know what broke and how you fixed it.

Caveat utilisor.