Conky

When one changes connection type (say, from ethernet to Wi-Fi), the interface name changes (e.g. eth0 → wlan1). To avoid changing Conky config file all the time, here’s a little Lua function for finding the network interface name.

function findInterface()
    local handle = io.popen('ip a | grep "state UP" | cut -d: -f2 | tr -d " "')
    local result = handle:read('*a'):gsub('\n$','')
    handle:close()
    return result
end

1. ip a gives everything about connection info. Each entry looks like

    3: wlp3s0f0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
   

2. Grep the “state UP” and extract the second field, using : as a delimiter. Trim off the spaces around.

   [Read More]

Background

I’m using Conky for monitoring the system. After a system upgrade, the CPU temperatures were gone. Conky’s standard error showed the following.

Conky: can't open '/sys/class/hwmon/hwmon0/temp3_input': No such file or
directory please check your device or remove this var from Conky...

Source of message: https://bbs.archlinux.org/viewtopic.php?id=82231

An easy fix would be to adjust the following lines in .conkyrc according to the number N in /sys/class/hwmon/hwmonN containing the file temp3_input. (You may adjust the number 3 according to the number of CPU of your device.) The number of CPU can be found using grep -c ^processor /proc/cpuinfo.

Background

I’ve to take screenshots to demonstrate Conky’s visual output.

I’ve chosen Byzanz after reading this answer on Ask Ubuntu.

Peek is more user-friendly, but I prefer CLI’s precision. That’s feasible thanks to a comment mentioning xwininfo.

After typing xwininfo, click on the target window. Switching to adjacent workplace is possible.

$ xwininfo
xwininfo: Please select the window about which you
          would like information by clicking the
          mouse in that window.

xwininfo: Window id: 0x1c0000a "Desktop"

  Absolute upper-left X:  0
  Absolute upper-left Y:  0
  Relative upper-left X:  0
  Relative upper-left Y:  0
  Width: 1920
  Height: 1080
  Depth: 32
  Visual: 0x1a7
  Visual Class: TrueColor
  Border width: 0
  Class: InputOutput
  Colormap: 0x1c00009 (not installed)
  Bit Gravity State: NorthWestGravity
  Window Gravity State: NorthWestGravity
  Backing Store State: NotUseful
  Save Under State: no
  Map State: IsViewable
  Override Redirect State: no
  Corners:  +0+0  -0+0  -0-0  +0-0
  -geometry 1920x1080+0+0

The --x and --y parameters below correspond to the absolute upper-left position of the window.