Automatically change wallpaper with Nitrogen

Thank you, I modified it a bit for future generations ... I hope you don't bother
I would like to know what you think, I don't know much about the language

#! / Bin / bash

# ~ Original author
#~
# ~ halonsov: Mathematician, GNU / LINUX lover, programmer, Debian and xmonad user.
#~
# ~ References
#~ https://blog.desdelinux.net/cambiar-automaticamente-el-fondo-de-pantalla-con-nitrogen/
#~
# ~ Command to run the script every 120 seconds
# ~ watch -n 120 /home/amem/backup/DataCrunch/Synaptic/RandomWallpaper.sh
#~
# ~ Collaboration
# ~ + AMEM +
# ~ Personally I prefer to use it only once so as not to use space
# ~ adding in autostart.sh
# ~ /home/amem/backup/DataCrunch/Synaptic/RandomWallpaper.sh &
# ~ Personal note
# ~ this script was originally made by halonsov.
# ~ I modified it so that only a little, to execute it at the beginning of #CrunchBang!
# ~ the purpose is that all those images that you have on your disk you can see them
# ~ every so often, and that they adjust to the screen according to their properties.
# ~ for this this script identifies the characteristics of your monitor,
# ~ and those of the image or photo of your «directory»,
# ~ in order to execute nitrogen + a scaling or zoom parameter avoiding
# ~ elongated, pixelated images.
# ~ If this script does not suit your needs, you can modify its parameters
# ~ Eg nitrogen –set-centered
# ~ to center the image without scaling
# ~ I recommend you study the nitrogen manual.

#Directory
#Directory of images to be used as wallpaper, including subdirectories
#Change to the directory where your wallpapers are located
# Eg directory = / home /… / images
directory = / home / amem / images / Wallpaper

# Monitor resolution
#This function detects the resolution of our monitor, and saves it in the variables:
function my_resolution ()
{
#We get the resolution of our monitor with xrandr
res = `xrandr | grep '*' | grep -o -E '[0-9] + x [0-9] +' `
#Height of the monitor
my_high = `echo" $ res "| cut -d "x" -f 2`
# Monitor width
my_width = `echo" $ res "| cut -d "x" -f 1`
}

#Random Image
#This function gets an image inside "directory"
function rand_image ()
{
#We get the name of some image inside $ directory
image = `ls -1 -b -R" $ directory "| grep -i -e ".png" -e ".jpg" -e ".jpeg" | sort –random-sort | head -1`

#IMPORTANT! If you notice we are filtering all files with "extension" .png, .jpg, .jpeg. Add -e ".extension" as appropriate.
#Example:
# image = `ls -1 -b -R" $ directory "| grep -i -e ".png" -e ".jpg" -e ".jpeg" -e ".new_extension" | sort –random-sort | head -1`

#We get the path of $ image
image_dir = `find" $ directory "-iname" $ ​​image "`
}

# Image resolution
#This function gets the resolution of the image obtained by the rand_imagen () function
function image_resolution ()
{
rand_image
#We get the height of $ image
high_image = `identify -format"% h "" $ image_dir "`
#We get the width of $ image
wide_image = `identify -format"% w "" $ image_dir "`
}

#We get the ratio image_resolution / screen_resolution
# the result of this division returns a value greater or less than 1
# proportion 1 the image is larger than the screen
function proportion ()
{
my_resolution
image_resolution
ratio_high = `echo $ image_high / $ my_high | bc -l`
width_proportion = `echo $ width_image / $ my_width | bc -l`
}

#We get the ratio image_high / image_width
# the result of this division returns a value greater or less than 1; Unless the image is square Oo
# image_proportion 1 the image is taller than it is wide
function image proportion ()
{
image_resolution
ratio_image_reason = `echo $ tall_image / $ wide_image | bc -l`
}

#Set the wallpaper
# This function modifies the nitrogen parameters according to the properties of the image in relation to the monitor
#Image too tall or larger than our screen Sets the wallpaper by scaling the image
# –Set-centered centers the unscaled image
# –Set-scaled fills the screen with the warped image
# –Set-zoom fills the screen with the scaled image to the top
# –Set-zoom-fill fills the screen with the scaled image along
scalar function ()
{
proportion
if [`echo" $ width_proportion> 1 ″ | bc` -eq 1]; then
#If the resolution of the image is larger than that of our screen, execute ...
nitrogen –set-scaled "$ image_dir"
else
if [`echo" $ high_rate> 1 ″ | bc` -eq 1]; then
#If the resolution of the image is smaller than that of our screen, execute ...
nitrogen –set-centered "$ image_dir"
else
#When the image is smaller than the screen we can expand it to length or width
image proportion
if [`echo« $ proportionimage_reason> 1 ″ | bc` -eq 1]; then
#If the height of the image is smaller than that of our screen, execute ...
nitrogen –set-zoom "$ image_dir"
else
if [`echo« $ proportionimage_reason <1 "| bc` -eq 1]; then
#If the width of the image is smaller than that of our screen, execute ...
nitrogen –set-zoom-fill "$ image_dir"
fi
fi
fi
fi
}

climb

exit