DietPi | Fix wrong shown connection state if IP+route is active but link "DOWN"

[MichaIng]

Status: Ready

• DietPi-Obtain_network_details
• Changelog

Reference: https://github.com/Fourdee/DietPi/issues/2573

Testing:

Old script:

root@VM-Stretch:~# time for i in {1..10}; do /DietPi/dietpi/func/obtain_network_details; done

real    0m1.645s
user    0m0.144s
sys     0m0.204s
root@VM-Stretch:~# time for i in {1..10}; do /DietPi/dietpi/func/obtain_network_details; done

real    0m1.632s
user    0m0.140s
sys     0m0.204s
root@VM-Stretch:~# time for i in {1..10}; do /DietPi/dietpi/func/obtain_network_details; done

real    0m1.611s
user    0m0.132s
sys     0m0.196s
root@VM-Stretch:~# time for i in {1..10}; do /DietPi/dietpi/func/obtain_network_details; done

real    0m1.611s
user    0m0.136s
sys     0m0.216s

New script:

root@VM-Stretch:~# time for i in {1..10}; do /DietPi/dietpi/func/obtain_network_details_new; done

real    0m0.641s
user    0m0.368s
sys     0m0.160s
root@VM-Stretch:~# time for i in {1..10}; do /DietPi/dietpi/func/obtain_network_details_new; done

real    0m0.651s
user    0m0.392s
sys     0m0.132s
root@VM-Stretch:~# time for i in {1..10}; do /DietPi/dietpi/func/obtain_network_details_new; done

real    0m0.648s
user    0m0.360s
sys     0m0.168s
root@VM-Stretch:~# time for i in {1..10}; do /DietPi/dietpi/func/obtain_network_details_new; done

real    0m0.646s
user    0m0.336s
sys     0m0.192s
root@VM-Stretch:~# cat /DietPi/dietpi/.network
0
0
eth0
192.168.178.29
ETH_IP=192.168.178.29
WLAN_IP=

• 🈯️ 🚀 Performance increase > 100%

Commit list/description:

• DietPi-Config | Fix wrong shown connection state where in some cases a route is shown but suffixed with "linkdown"
• DietPi-Obtain_network_details | Rewrite: Scan more targeted via /sys/class/net entries: Performance!
• DietPi-Obtain_network_details | Verify that device with assigned IP is actually connected, via "ip a" =~ "UP" flag