df -P /dev/sda1 | grep /dev/sda1 | awk '{ print $5}' | sed 's/%//g'

df -P /dev/disk/by-uuid/0E5E17800E5E1780 | grep /dev/disk/by-uuid/0E5E17800E5E1780 | awk '{ print $5}' | sed 's/%//g'

#!/bin/bash
inputa=90
#outputa=$(df -P /dev/sda1 | grep /dev/sda1 | awk '{ print $5}' | sed 's/%//g') #disque sda1 /home/user/Documents/ipcams/ipcam
outputa=$(df -P /dev/disk/by-uuid/0E5E17800E5E1780 | grep /dev/disk/by-uuid/0E5E17800E5E1780 | awk '{ print $5}' | sed 's/%//g')

if  [ "$inputa -lt $outputa" ]
then
     find /home/user/Documents/ipcams/ -type f -name "*.mp4" -print > /home/user/ipcam.log
    (date +"%Y-%m-%d Heure:  %H-%M-%S") >> /home/user/ipcam.log
      echo Pourcentage $outputa "%" >> /home/user/ipcam.log

else echo rien

fi

$ df -P /dev/sda1 | awk 'NR == 2 { print substr($5,1,length($5)-1) }'
80

$ df -P /dev/disk/by-uuid/79b5546e-5b3e-4299-becb-5f0cad06cf5f | awk 'NR == 2 { print substr($5,1,length($5)-1) }'
80

df displays the amount of disk space available on the file system containing each file name argument.