Puppy Linux Discussion Forum

BarryK wrote: Fri Oct 30, 2020 7:44 amHas anyone had experience with using "file-monitor", is there something wrong with the syntax the way I am trying to do it?

#!/bin/sh
echo '
<window>
<vbox>
<edit visible="false" file-monitor="true">
	<input file>/tmp/found-new-devices</input>
	<action signal="file-changed">refresh:TEXT</action>
</edit>
<text>
	<variable>TEXT</variable>
	<input>echo $(($TEXT+1))</input>
</text>
<button label="Write to found-new-devices">
	<action>echo blabla > /tmp/found-new-devices </action>
</button>
</vbox>
</window>' | gtkdialog -s

@some1 Yes, it works for me too in fossapup64 but not in a pristine Slacko5.6. Both use gtkdialog 0.8.4 but the builds are different.

@ BarryK No, the <button> widget is not the culprit here. Even without using the button (e.g. external "echo > /tmp/found-new-devices" ) the action fires twice. No way around it. Your gtkdialog may behave differently.

As you noticed using touch to change the modify date doesn't fire the action. Same with editing the file in an editor and save it. Nothing happens. This is plain wrong, also in fossapup64. Your posted wordaround, saving the monitored file to itself, certainly works, but let's face it: it's an ugly solution.

Bottomline for me: file-monitor is inflexible (unchangeable interval, monitors only mtime) and is unreliable.

What works for me even in Slacko5.6 and is much more flexible: A timer that checks whatever has to be checked (e.g. changed file size, time, permission or even changes in a whole directory) and then triggers one or more actions.

Here an example.The timer periodically stats the monitored file, checking the file's mtime. If different from previous time (saved in text widget SAVEDTIME ) the counter increases by 1 and SAVEDTIME is updated. Touch command and saving from editor work as expected.

function mtime { stat -c %Y /tmp/found-new-devices ;} # time of last modification, seconds since Epoch
export -f mtime

echo '<window><vbox>
<timer visible="false" interval="1">
	<action condition="command_is_true( echo $(($(mtime) - SAVEDTIME)) )">refresh:COUNTER</action>  
	<action condition="command_is_true( echo $(($(mtime) - SAVEDTIME)) )">refresh:SAVEDTIME</action>  
</timer>
<text visible="false">
	<variable>SAVEDTIME</variable>
	<input>mtime</input>
</text>
<text>
	<variable>COUNTER</variable>
	<input>echo $(($COUNTER+1))</input>
</text>
<button label="Write to found-new-devices">
	<action>echo blabla > /tmp/found-new-devices </action>
</button>
</vbox></window>' | gtkdialog -cs 

BarryK wrote: Sat Oct 31, 2020 2:02 amIf the file is written to externally, say "echo > /tmp/found-new-devices", then the action in the timer only fires once.

MochiMoppel wrote: Sun Nov 01, 2020 7:47 am

BarryK wrote: Sat Oct 31, 2020 2:02 amIf the file is written to externally, say "echo > /tmp/found-new-devices", then the action in the timer only fires once.

Seems to be more complicated. Here is what I found:

command	fires	remark
echo > file	twice	the quoted example, writes 1 character
echo -n > file	once	writes a null string, creates zero length file
echo bla > file	twice	writes a string
echo bla >> file	once	appends a string