I am trying to use dbus-send to get the total number of page from zathura (Zathura is a PDF viewer) (See figure below). I am not familiar with DBus (no matter how I try to learn it, I always give up).

I could use a GUI program to see the total number of pages numberofpages when I double click on that property I get the value.

However, I am trying to get the same information using dbus-send. I tried the following on the terminal:

dbus-send --session --dest=org.pwmt.zathura.PID-1057698 \
 --print-reply org.pwmt.zathura.Properties.numberofpages

The command above doesn't work.

Could you please tell me how can I construct a dbus-command to get the numberofpages value?

CodePudding user response：

This might be easier to do using busctl rather than dbus-send. Either way there is four bits of information you need to know for most D-Bus situation.

1. Bus Name: org.pwmt.zathura.PID-1057698
2. Path: /org/pwmt/zathura
3. Interface: org.pwmt.zathura
4. Property: numberofpages

I would expect your situation to look like:

busctl --user get-property org.pwmt.zathura.PID-1057698 /org/pwmt/zathura org.pwmt.zathura numberofpages 

To try this on a service that is likely to be running on most machines:

1. Bus Name: org.freedesktop.systemd1
2. Path: /org/freedesktop/systemd1
3. Interface: org.freedesktop.systemd1.Manager
4. Property: Architecture

And to run it with both utilities:

dbus-send

$ dbus-send --session --print-reply --dest=org.freedesktop.systemd1 /org/freedesktop/systemd1 org.freedesktop.DBus.Properties.Get string:"org.freedesktop.systemd1.Manager" string:"Architecture"
method return time=1650033765.273653 sender=:1.0 -> destination=:1.176 serial=2677 reply_serial=2
   variant       string "x86-64"

busctl

$ busctl --user get-property org.freedesktop.systemd1 /org/freedesktop/systemd1 org.freedesktop.systemd1.Manager Architecture 
s "x86-64"

CodePudding user response：

After wrestling with dbus-send command, finally I found the right syntax:

dbus-send --session  --print-reply \
 --dest=org.pwmt.zathura.PID-1057698\ 
 /org/pwmt/zathura \
 org.freedesktop.DBus.Properties.Get \
 string:org.pwmt.zathura string:numberofpages

The output of that command is:

method return time=1650032068.076028 sender=:1.2273 -> destination=:1.2408 serial=79 reply_serial=2
   variant       uint32 46

I can use grep to get the value 46 (which is in my case the total number of pages in the PDF document).