On Linux systems, `ifconfig` is long deprecated in favor of the `ip`
command from iproute2. Some systems don't have iproute2 (BSDs in
particular), so ddclient will still attempt `ifconfig` if `ip` is
missing.
Also: Don't hide STDERR because error messages are important for
troubleshooting problems. To avoid STDERR noise on systems without the
`ip` command, the command's existence is checked before it is run.
Notes:
* The fetched addresses could be limited to IPv4 or IPv6 depending
on `opt('ipv6')`, and non-global addresses could be filtered out,
but any filtering risks breaking a nontrivial number of existing
configurations.
* This change runs the risk of breaking existing configs that set
`if-skip`. Due to the deprecation of `ifconfig`, and the belief
that only a negligible number of users set `if-skip`, the benefits
of this change are believed to outweigh the config migration
burden imposed on users.
Fixes#93.
If the user passed `-ip` they almost certainly want to use it, even if
they also passed `-if` and `-web`.
Similarly, if the user passed `-if` they almost certainly want to use
it even if they also passed `-web`.
This allows us to use the `//` and `//=` operators.
v5.10.1 was chosen because that is the oldest version of Perl among
all currently supported releases of Ubuntu, CentOS, RHEL, Fedora, and
Debian.
Create a document whose main purpose is to describe notable changes
between released versions. Populate it with the contents of
RELEASENOTE over time and the entries from ChangeLog and
Changelog.old.
For recent releases, the full announcement text can still be found at
https://github.com/ddclient/ddclient/releases
