Tag: script

Using the REST api to read sensors on Home assistant

9 November 202114 March 2023 Fabien Linux, Networking Leave a comment

During one of my little project of making timelapses videos with some IP cameras, I had the following problem : How do you stop capturing new images at night when the camera see nothing,
After all , the sun rise and sun set time are changing everyday ! and i didn’t see a simple way to calculate this.
then i remembered the sun.sun integration in Home assistant.

If i had a simple way to query this integration in my script , i could very simply stop my script when the sun was no longer present in the sky !

The Home assistant REST API

In any home assistant installation there is access to a REST API that lets you do a lot a things , but in my case, I don’t want much , I just want to know if the sun is above or below the horizon.

Get a Authorization: Bearer token
you first have to generate a token to authenticate your request . You have to go to your user section , this is the circle a the bottom of the toolbar, then at the bottom of the page , you can create a long term token ,
Please take note of this token because Home assitant can only display it one time , if you loose it , you must recreate an other one.

Then in my script i can use this

curl -s -X GET -H "Authorization: Bearer eyJ0eX....G9QCqY" -H "Content-Type: application/json" http://192.168.1.13:8123/api/states/sun.sun |jq -r .state

it will return either above_horizon or below_horizon, I can then use this in my script to stop the capture when it’s below_horizon

I used jq filter the json result , but , if you can’t or don’t want to install it , you can replace it with this simple awk

 awk -F "\"" {'print $8'}

Bash script to clean movies name

22 June 201722 June 2017 Fabien bash, Linux 3 Comments

The issue when you download movies online, is that most of the time the file name is going to be complete trash , filled with useless info like the team that made the rip or the website from where the movie was downloaded.
This is very annoying when you sort by name and the website made the idiotic decision to put their name in front of the actual film name.

for example here a typical movie name
[ Torrent9.info ] Dont.Think.Twice.2016.FRENCH.WEBRip.XviD-NEWCiNE.avi
the actual useful data that i wish to keep is Dont.Think.Twice.2016.avi

for this purpose i’ve developped a small bash script that will list all the files in a chosen directory then , if necessary , will rename the file.

#!/bin/bash
#the location of the folder full of movies to rename.
for file in /media/freebox/*
do
if [[ -f $file ]]; then
#that line will delete all the text after the date but keep the file extension.
nfile=$(echo $file | sed "s/\(20[0-1][0-8]\).*\(mkv\|avi\|mp4\)/\1.\2/")

#this line is going to try to delete a space a the start of the filename if it exist
nfile=$(echo $nfile | sed  "s/\/ /\//")

#this line is going to delete double dots in the filename and replace them with simple dots
nfile=$(echo $nfile | sed -e "s/\.\./\./g")

#that line is going to delete everything between [] including the [] 
nfile=$(echo $nfile | sed -e 's/\[[^][]*\]//g')


#after all this work on the filename
#you can now check if the any changes have been made , 

if [[ "$file" == "$nfile" ]]
then
   #if no change display this
   echo "Not touched : $file"
else
   #if change detected , rename the file
   echo ______
   echo Renamed :
   echo "Original name : $file"
   echo "Renamed to  : $nfile"
   echo ______
#doing the actual renaming
mv "$file" "$nfile"
fi
fi
done

this is not a very efficient script
but it’s fulfill it’s purpose and very rarely encounter a filename that he is unable to clean.

BASH:check if a number is even or odd

19 June 201719 June 2017 Fabien Linux 5 Comments

In a bash script you might need to check if a var is even or odd ,

in my case im going to use a if to make that check

#!/bin/bash
for i in $(seq 10);do
    if (( $i % 2 )); then
        echo $i is odd
    else
        echo $i is even
    fi
done

You can use this simple code to make that check and display the result.

the result will be :


1 is odd
2 is even
3 is odd
4 is even
5 is odd
6 is even
7 is odd
8 is even
9 is odd
10 is even

BASH : IP validation

30 May 201730 May 2017 Fabien Linux Leave a comment

if you have a list of ip to validate ,
you can use this little bash script ,
this will open your IP list ,
then test if all the 4 numbers that make a standard IP.are beeten 0 and 255

if the ip is valid then the script will return valid , else it will return : not valid

for IP_ADDRESS in `cat ip-list.txt` ; do
#this var is a test that will see if the number is beetween 1 and 254
test='([1-9]?[0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])'
if [[ $IP_ADDRESS =~ ^$test\.$test\.$test\.$test$ ]]; then
echo "valid:     "$IP_ADDRESS
else
echo "not valid: "$IP_ADDRESS
exit
fi
done

after execution , you will get the following result :

valid:     127.0.0.1
valid:     8.8.8.8
valid:     82.48.250.6
valid:     230.230.230.230
not valid: 255.255.2301
valid:     8.8.4.4
not valid: 80.46.70.22.5
valid:     255.255.255.0
valid:     0.0.0.0

Bash : Delete some characters from a file with TR

23 May 201728 May 2017 Fabien Linux Leave a comment

in this little example of usage of the command tr
we want to clean a file so the values contained in it can be used
Example File

<10>
<23>
<34>
<78>
<44>
<12>
<40>
<81>
<30>
<11>
<14>
<09>
<02>
<66>

In my example i wish to only keep the value and deleting the character < and >

 cat file| tr -d '<>'

the tr command used with the -d (delete) option will allow you to delete the list of characters contained between the quotes.

You will obtain the following result

BASH : Delete the last X chars from a string

25 April 20177 May 2017 Fabien Linux Leave a comment

sed delete last x chars

When you scrap data in HTML , it’s common , depending on the quality of you regex to end up with a string with some useless character at the end (Or the Beginning),

If you string looks like that :

My useful data</a> <

You can use the command head to drop the X last character of your string ,
So in my Case , to Keep only the string My useful data and drop the </a> <

I’m going to pipe my string to

head -c -6

This will delete the last 6 chars of my string , giving the data that i need later in my script

but in some implementation of the head command this will not work ,

you can use an alternative with sed

sed 's/.\{6\}$//'

This will delete the last 4 characters of your line , or alternatively

sed 's/......$//'