Re: [PATCH] _find_net_interfaces: use /sys/class/net/* for interface names in linux

[Eric Cook <llua@xxxxxxx>]

On 08/11/2015 05:47 AM, Oliver Kiddle wrote:
> Eric Cook wrote:
>> I also wasn't able to find the type of tunnels mentioned in
>> http://www.zsh.org/mla/workers/2007/msg00111.html that doesn't show up
>> in /proc/sys/net/ipv4/conf/. Maybe at some point since then, that was
>> fixed. But to avoid some kind of regression /sys/class/net/ seems usable
>> for the time being.
>
> One example, is aliases. So if you do something like
>   ifconfig eth0:1 192.168.42.37
> then ifconfig will show eth0:1 while /sys/class won't.
>
> There may be cases where we don't want to complete those, however.

Are there programs that actually work with aliases interface names? The ones I have seen, not many(ifdown/ifup), assumes you are attempting to address
the actual interface.
>> diff --git a/Completion/Unix/Type/_find_net_interfaces b/Completion/Unix/Type/_find_net_interfaces
>> index 0c70335..f90f310 100644
>> --- a/Completion/Unix/Type/_find_net_interfaces
>> +++ b/Completion/Unix/Type/_find_net_interfaces
>> @@ -23,7 +23,7 @@ case $OSTYPE in
>>    irix*) net_intf_list=( ${${${(f)"$(/usr/etc/netstat -i)"}%% *}[2,-1]} ) ;;
>>    *linux*)
>>      if (( $+commands[ip] )); then
>> -      net_intf_list=( ${${(m)${(f)"$(ip -o link)"}#*: }%%: *} )
>> +      net_intf_list=( /sys/class/net/*(N:t)  )
>>      fi
>>    ;&
>
> The (( $+commands[ip] )) isn't really applicable after that change.

Whoops.
> Also did you notice that we still have the following further down in the
> function:
>     if [[ -d /proc/sys/net/ipv4/conf ]]; then
>       # On linux we used to use the following as the default.
>       # However, we now use ip or ifconfig since it finds additional devices such
>       # as tunnels.  So only do this if that didn't work.
>       net_intf_list=( /proc/sys/net/ipv4/conf/*~*(all|default)(N:t) )
>     fi
>
> I think the /proc path there will work for older Linux installations
> than the /sys path you use and it still works with new systems.
>
> Oliver
>
I noticed it and found /sys/class/net on the oldest linux installs i have access to, centos 4.x.
The linux block in the case statement is a fall through. If /sys/class/net
doesn't exist it will fall back to using ifconfig or /proc/sys/net/ipv4/conf/ since the array
net_intf_list is still empty.

I've fixed my original patch, but if you want to solve it another way, go for it :D

diff --git a/Completion/Unix/Type/_find_net_interfaces b/Completion/Unix/Type/_find_net_interfaces
index 0c70335..32c920f 100644
--- a/Completion/Unix/Type/_find_net_interfaces
+++ b/Completion/Unix/Type/_find_net_interfaces
@@ -22,9 +22,7 @@ case $OSTYPE in
   darwin*|freebsd*|dragonfly*) net_intf_list=( $(ifconfig -l) ) ;;
   irix*) net_intf_list=( ${${${(f)"$(/usr/etc/netstat -i)"}%% *}[2,-1]} ) ;;
   *linux*)
-    if (( $+commands[ip] )); then
-      net_intf_list=( ${${(m)${(f)"$(ip -o link)"}#*: }%%: *} )
-    fi
+    net_intf_list=( /sys/class/net/*(N:t) )
   ;&
 
   *)