"hostname -I" should be "hostname -i"?

[GoogleCodeExporter]

using ash 0.5.r .r158 on arch linux i get the following error message:

/bin/hostname: invalid option -- 'I'
Try 'hostname --help' or 'hostname --usage' for more information.

changing the GetHostIp() function in unix.py (line 49) from "hostname -I" to 
"hostname -i" fixes the problem for me...

Original issue reported on code.google.com by [email protected] on 18 Apr 2013 at 2:49

[GoogleCodeExporter]

From the hostname man page in Ubuntu:

       -I, --all-ip-addresses
              Display   all   network  addresses  of  the  host.  This  option
              enumerates all configured addresses on all  network  interfaces.
              The   loopback  interface  and  IPv6  link-local  addresses  are
              omitted. Contrary to option -i, this option does not  depend  on
              name  resolution. Do not make any assumptions about the order of
              the output.

So, if you have a --all-ip-addresses flag, this is what you probably want.  I'm 
not sure if / when the arch linux hostname command will get -I, but -i is 
probably not ideal.

On my machine, hostname -i gives me the IPv4 loopback address - this is not 
really useful information.

That being said, I can look into making the method for finding the host IP 
address configurable.

Original comment by [email protected] on 23 Apr 2013 at 3:56

[GoogleCodeExporter]

thanks for that.

it seems that Arch uses GNU hostname (from GNU inetutils:
http://www.gnu.org/software/inetutils/manual/inetutils.html#hostname-invocation)
which has fewer options than debian hostname...

Original comment by [email protected] on 23 Apr 2013 at 4:16

[GoogleCodeExporter]

I'm sure there is a more pythonic way to get the ip addresses of the current 
machine - I was being lazy and thought hostname -I was a safe bet.  I'll see if 
I can't figure it out and submit a change soon.

Oh, and the C++ version may work for you in the meantime.

Original comment by [email protected] on 23 Apr 2013 at 11:02

[GoogleCodeExporter]

So, the obvious thing to try is:
  you@yourhost:~$ python
  >>> import socket
  >>> socket.gethostbyname(socket.gethostname())
  '123.45.67.8'

If this works, this is one way easy way to do it.

Otherwise, this method looks promising:
http://stackoverflow.com/a/9267833

Original comment by [email protected] on 23 Apr 2013 at 11:15

[GoogleCodeExporter]

works for me fwiw... might be easier to maintain since it's one less
dependency...

Original comment by [email protected] on 24 Apr 2013 at 1:54

[GoogleCodeExporter]

I have scrapped the idea of using fcntl to parse devices.  Instead I'm scraping 
the information I want from ifconfig.

I've loosely tested this on OSX and Ubuntu Precise.

If you have a chance, please check out the head and see if it works for you.

Original comment by [email protected] on 30 Apr 2013 at 7:01

[GoogleCodeExporter]

fwiw, ifconfig is deprecated in Arch, though it is available in the package
net-tools. /usr/sbin/ip is installed by default... equivalent usage is "ip
addr" or "ip a"

iirc fedora does something similar

might be wise to test for /sbin/ifconfig rather than assume it's available?
if it helps, i can provide a patch to make subprocess use ip if it can't
find ifconfig & then parse out the ip & mac addresses. let me know

here's some background in case it's useful:

https://www.archlinux.org/news/deprecation-of-net-tools/
http://blog.timheckman.net/2011/12/22/why-you-should-replace-ifconfig/

Original comment by [email protected] on 30 Apr 2013 at 7:42

[GoogleCodeExporter]

I am using the python version on Mac OS X and also noticed that "hostname -I" 
doesn't work.  I am attaching a patch that lets the user pass in a command to 
use to determine the host IP.  That workaround was good enough to get me going.

Original comment by [email protected] on 7 Jun 2015 at 1:42

Attachments:

• unix_py_patch
• ash_conf_patch