bash kdialog messages - kde - explaing how line works

English Programming/Scripting
#1

I’ve read about this on webpages. I still can’t make logical sense of it. Do I need to fix this? What does this output mean? If yes, how do I fix it.

Menu_Select=$(kdialog --radiolist "SCANVIRUS:  Main Menu" 1 "Scan Systems" on 2 "Scanlog Menu" off 3 "View Menu" off 4 " " off 5 "Kill All Scans" off 6 " " off 7 "Show Help Menu" off)
No protocol specified
QStandardPaths: XDG_RUNTIME_DIR not set, defaulting to '/tmp/runtime-root'
QStandardPaths: XDG_RUNTIME_DIR not set, defaulting to '/tmp/runtime-root'

Can someone explain to me how this line works? Unlike the above, it doesn’t return a value, yet It returns a value using this format. Remove ‘&& echo 1’ and it will not return a value.

Menu_Select=$(kdialog --title "SCANVIRUS:  Main Menu" --yesno "Kill All Scans" && echo 1)
#2

I’m still stuck and getting nowhere. Need help.

#3

Hi,

I’m not perfectly sure, but I’ll try a guess.

kdialog --radiolist and --yesno return different types of values. The first line works perfercly in the shell:

kasi@pluto:~/Schreibtisch> Menu_Select=$(kdialog --radiolist "SCANVIRUS:  Main Menu" 1 "Scan Systems" on 2 "Scanlog Menu" off 3 "View Menu" off 4 " " off 5 "Kill Al Scans" off 6 " " off 7 "Show Help Menu" off) 
kasi@pluto:~/Schreibtisch> echo $Menu_Select 
5

kdialog returns the value 5 after selecting the “Kill Al” and applies it to the variable Menu_Select.
Not sure where the error messages in your example are coming from, probably from somewhere else in your script.

kdialog --yesno just returns a boolean, I suppose. && is a logical AND. It will process the second command only if the first one finishes successfully without an “error”, resp. with a 0. So, when hitting “yes” the echo command will be processed and the result applied to the variable. I chose a different one for this example:

kasi@pluto:~> onkel=$(kdialog --title "SCANVIRUS:  Main Menu" --yesno "Kill All Scans" && echo 1) # then hit "yes"
kasi@pluto:~> echo $onkel
1
kasi@pluto:~> onkel=$(kdialog --title "SCANVIRUS:  Main Menu" --yesno "Kill All Scans" && echo 1) # then hit "no"
kasi@pluto:~> echo $onkel

kasi@pluto:~> onkel=$(kdialog --title "SCANVIRUS:  Main Menu" --yesno "Kill All Scans" && echo 42) # then hit "yes"
kasi@pluto:~> echo $onkel
42
kasi@pluto:~> #and so on...

Did I get your issue?
Cheers!

kasi

#4

I didn’t explain clear enough. So, again.

Menu_Select=$(kdialog --radiolist "SCANVIRUS:  Main Menu" 1 "Scan Systems" on 2 "Scanlog Menu" off 3 "View Menu" off 4 " " off 5 "Kill All Scans" off 6 " " off 7 "Show Help Menu" off)
-->No protocol specified
-->QStandardPaths: XDG_RUNTIME_DIR not set, defaulting to '/tmp/runtime-root'
-->QStandardPaths: XDG_RUNTIME_DIR not set, defaulting to '/tmp/runtime-root'

I’v searched for those messages. I can’t find a clear answer on what they are or how to fix them.

# echo $(kdialog --title "SCANVIRUS:  Main Menu" --yesno "Kill All Scans")
No protocol specified
QStandardPaths: XDG_RUNTIME_DIR not set, defaulting to '/tmp/runtime-root'
QStandardPaths: XDG_RUNTIME_DIR not set, defaulting to '/tmp/runtime-root'

There is no returned number on selecting ‘no’.

# echo $(kdialog --title "SCANVIRUS:  Main Menu" --yesno "Kill All Scans")
No protocol specified
QStandardPaths: XDG_RUNTIME_DIR not set, defaulting to '/tmp/runtime-root'
QStandardPaths: XDG_RUNTIME_DIR not set, defaulting to '/tmp/runtime-root'

There is no returned number on selecting 'yes". It should return ‘1’(or some value).

This is a bug in the function. All other functions return a value

echo $(kdialog --title "SCANVIRUS:  Main Menu" --yesno "Kill All Scans" && echo 1)
No protocol specified
QStandardPaths: XDG_RUNTIME_DIR not set, defaulting to '/tmp/runtime-root'
QStandardPaths: XDG_RUNTIME_DIR not set, defaulting to '/tmp/runtime-root'

Press ‘no’, returns nothing.

# echo $(kdialog --title "SCANVIRUS:  Main Menu" --yesno "Kill All Scans" && echo 1)
No protocol specified
QStandardPaths: XDG_RUNTIME_DIR not set, defaulting to '/tmp/runtime-root'
QStandardPaths: XDG_RUNTIME_DIR not set, defaulting to '/tmp/runtime-root'
1

Press ‘Yes’, returns nothing.

You have to add the ‘&& echo 1’ to make it work. This is either design flaw or bug in this function.

#5

kdialog failed to connect to X server. Likely because you run it from su or sudo session.

This is either design flaw or bug in this function.

Of course, everything that you do not understand is a bug.

kdialog is documented pretty well. Have you tried to actually read it?

#6

-radiolist and -checklist(and others) work as they should. Reading the docs on the kde manual page is how I was able write the rest of the code.

You still haven’t answered why the function needs ‘&& echo 1’. The other two don’t need it. This is clearly a design flaw in the function that makes it harder to use and understand. That part of the line shouldn’t be needed.

It should be this:

cancel/close x=-1(also null string)
yes=0
no=1

Based on a normal bash function.

I can bypass this by using the other functions. I’m trying to make the code as readable as possible.

#7

Because you wrote it this way. Nothing prevents you from checking exit code directly.

#8

Actually, the --yesno does return (correct) values:

kasi@pluto:~> kdialog --yesno "hello world" ; echo $? # hit yes 
0 
kasi@pluto:~> kdialog --yesno "hello world" ; echo $? # hit no 
1 
kasi@pluto:~> kdialog --yesno "hello world" ; echo $? # hit esc 
2

But it seems they can’t be read directly in the function. So a little more code may be required.

https://mostlylinux.wordpress.com/bashscripting/kdialog/#yes-no

#9

You can use the 0 or not-0 of the return code directly.

kdialog --yesno "hello world" && echo OK