uci: unnecessary write accesses

[Florian Eckert]

I have written a small shell script, to track write access to the 
'/etc/config' directory.
For this task I am using the inotify-tool package [1].
I am using the inotifywait tool to add the watchers [2] with a small 
shell script and log them to the syslog.

If I change a 'uci' option with the  the 'uci' commands, then I get 
create and write events for a temporary file in the '/etc/config/' 
directory.
I didn't expect it to be like this.

For example, if I now change a file using the 'uci' command, a tmp file 
is created under '/etc/config'.
Is this correct? Or do we have a problem there.
I have always thought that for embedded systems with flashes it is 
important to make as few write accesses as possible.

Shell commands to change uci config:

root at st-dev-07 ~ # uci set system.led_Power.trigger=none
root at st-dev-07 ~ # uci commit system

Log output of my Script:

Tue Sep 21 12:50:38 2021 daemon.info loginotify[17375]: 
{"directory":"/etc/config/","file":".system.uci-fEGgbp","event":"CREATE","time":"09/21/21 
12:50:38"}
Tue Sep 21 12:50:38 2021 daemon.info loginotify[17375]: 
{"directory":"/etc/config/","file":".system.uci-fEGgbp","event":"MODIFY","time":"09/21/21 
12:50:38"}
Tue Sep 21 12:50:38 2021 daemon.info loginotify[17375]: 
{"directory":"/etc/config/","file":".system.uci-fEGgbp","event":"MODIFY","time":"09/21/21 
12:50:38"}
Tue Sep 21 12:50:38 2021 daemon.info loginotify[17375]: 
{"directory":"/etc/config/","file":".system.uci-fEGgbp","event":"CLOSE_WRITE,CLOSE","time":"09/21/21 
12:50:38"}
Tue Sep 21 12:50:38 2021 daemon.info loginotify[17375]: 
{"directory":"/etc/config/","file":"system","event":"CLOSE_WRITE,CLOSE","time":"09/21/21 
12:50:38"}
Tue Sep 21 12:50:38 2021 daemon.info loginotify[17375]: 
{"directory":"/etc/config/","file":".system.uci-fEGgbp","event":"ATTRIB","time":"09/21/21 
12:50:38"}

I am bothered about the file '.system.uci-fEGgbp'?


To do this without my script on the console, the following command can 
be used on the shell:
inotifywait --quiet --monitor -e 
"create,delete,modify,close_write,attrib" /etc/config

Then you will get the following output if you change an option with uci:
/etc/config/ CREATE .system.uci-lOlFid
/etc/config/ MODIFY .system.uci-lOlFid
/etc/config/ MODIFY .system.uci-lOlFid
/etc/config/ CLOSE_WRITE,CLOSE .system.uci-lOlFid
/etc/config/ CLOSE_WRITE,CLOSE system
/etc/config/ ATTRIB .system.uci-lOlFid

---
Florian

[1] 
https://github.com/openwrt/packages/blob/master/utils/inotify-tools/Makefile
[2] https://www.man7.org/linux/man-pages/man1/inotifywait.1.html