[SOLVED] Zenity --text-info shows more than I would hope for

Michael Uplawski · 02-06-2016, 01:36 AM

Edit: the call to 'echo' was missing in the script, below. (sorry)

Good morning,

To demonstrate the use of Zenity, I came up with this script-example

Code:

 
#!/bin/dash
IP=$(zenity --title "traceroute" --entry --text "IP or domain")

if [ "$IP" != '' ]
then
 	echo $(traceroute $IP) | zenity --text-info
#	xterm -e "traceroute $IP"
fi

The output is not formatted, as I do not yet care. The content however, is worrying me. After the first line from traceroute, the content of the current dircetory, where I put the script, is shown three times, then the remainder from traceroute. Screen shot: http://pix.toile-libre.org/upload/img/1454742731.png

A call to traceroute in a terminal-emulator looks normal, and you can replace traceroute by whois in the above script to get the same ugly result, but at least no surprises. If there is something wrong with traceroute, I wonder why it is becoming visible only when using redirection with $() ...

Have a nice week-end, all. And if someone knows something that I have not yet seen or should modify in my call to traceroute and zenity, please tell me.

Cheerio,

Michael

Michael Uplawski · 02-06-2016, 02:13 AM

Work-around

Even if there is no explicit question in my original post, above, part of the answer may be to write the output to a temporary file and use the --filename parameter of Zenity. This is not a solution and does not help to explain the strange behaviour of the original script. But it works and even corrects the formatting:

Code:

#!/bin/dash
IP=$(zenity --title "traceroute" --entry --text "IP or domain")

if [ "$IP" != '' ]
then
	tfile=`mktemp`

#	 echo "writing to $tfile"

	traceroute "$IP" > "$tfile"
 	zenity --text-info --filename="$tfile"
	rm -f "$tfile"

#	echo $(traceroute $IP) | zenity --text-info
#	xterm -e "traceroute $IP"
fi

Michael Uplawski · 02-06-2016, 02:32 AM

Just for completeness. Replacing zenity by yad, I get the same additional content in the text-info dialog. Only the formatting is different, but that does not matter. I recommend to either pipe the traceroute-output directly to Zenity/Yad or to read from a temporary file, as in the example, above.

... but still, I would like to know what's strange about echo $(traceroute google.com).

Michael Uplawski · 02-06-2016, 06:35 AM

The solution:
"$(traceroute [ip or domain]"
Explication:
As traceroute produces asterisks, these are interpreted as the wild-card character which will be applied to the content of the current directory and match all the file-system-objects in reach. Quote-marks quote the asterisks and just hand them over as String components to the receiving end (a variable, another command or STDOUT).

I do not remember if I once had known this. Traceroute is innocent.