Shell script to open random jpegs with ImageMagick

Question

I have a large batch of jpegs. I would like to write a shell script that selects 5 images randomly and then, using imageMagick, put them in a montage and then open this montage file. I would like this process to occur every 10 seconds.

I have tried this script

for f in *.jpg
do
shuf -ezn 5 * | xards -0 -n1 | montage *.jpg | display montage.jpg
done

but it is not working

It opens all of the images and gives me the following error message

image.sh 7: image.sh: Xards: not found 

the go.sh script is kept in the same folder/directory as the images and now looks like this:

#!/bin/bash 

# Get list of files into array - just once at start
files=(*.jpg)

# Do forever
first=0
while :; do
   # Shuffle array
   files=( $(shuf -e "${files[@]}") )

   # Make montage of first 5 images in shuffled array
   magick montage ${files[0]} ${files[1]} ${files[2]} ${files[3]} ${files[4]} montage.jpg

   # Start displaying if first pass - leaving "display" running in background updating itself every second
   if [ $first -eq 0 ] ; then
      display -update 1 montage.jpg &
      first=1
   fi

   # Snooze 10 and repeat
   sleep 10
done

However that is returning

go.sh: 4: go.sh: Syntax error: "(" unexpected

However, when I run

bash go.sh

ImageMagick opens all images in the folder in one montage and I get the following error

go.sh: line 12: magick: command not found

Answer 1

Do you want to concat the images? In this case you could do something like:

while true; do    
sleep 10;
montage -mode concatenate -tile 1x $(ls | sort -R | tail -n 5 | paste -sd " " -) montage.jpg && display montage.jpg;
done

Answer 2

Something like this:

#!/bin/bash

# Get list of files into array - just once at start
files=(*.jpg)

# Do forever
first=0
while :; do
   # Shuffle array
   files=( $(shuf -e "${files[@]}") )

   # Make montage of first 5 images in shuffled array
   magick montage ${files[0]} ${files[1]} ${files[2]} ${files[3]} ${files[4]} montage.jpg

   # Start displaying if first pass - leaving "display" running in background updating itself every second
   if [ $first -eq 0 ] ; then
      display -update 1 montage.jpg &
      first=1
   fi

   # Snooze 10 and repeat
   sleep 10
done

---

Or this might be easier to understand:

#!/bin/bash

# Get list of files into array
files=(*.jpg)

montage=/tmp/montage.jpg

# Create initial "Loading sign"
convert -background black -fill white -pointsize 64 label:"Loading" $montage
display -update 1 $montage &

# Do forever
while :; do
   # Shuffle array
   files=( $(shuf -e "${files[@]}") )

   # Make montage
   magick montage ${files[0]} ${files[1]} ${files[2]} ${files[3]} ${files[4]} $montage

   # Snooze 10 and repeat
   sleep 10
done

---

Users of macOS may not have X11 support built into ImageMagick, they can install feh using homebrew like this and also shuf (actual command is gshuf) from GNU coreutils:

brew install feh
brew install coreutils

and try the following version:

#!/bin/bash

# Get list of files into array
files=(*.jpg)

montage=/tmp/montage.jpg

# Create initial "Loading sign"
convert -background black -fill white -pointsize 64 label:"Loading" $montage

# Display "feh" running continuously in background passing the same image twice so we can cycle through the list!
feh --title "My Funky Montage" $montage $montage &
fehpid=$!

# Do forever
while :; do
   # Shuffle array
   files=( $(gshuf -e "${files[@]}") )

   # Make montage
   magick montage ${files[0]} ${files[1]} ${files[2]} ${files[3]} ${files[4]} $montage

   # Cycle feh to next image
   kill -s USR1 $fehpid

   # Snooze 10 and repeat
   sleep 10
done