Make example scripts more portable

example_scripts/swww_randomize.sh

@@ -1,32 +1,28 @@
-#!/bin/bash
+#!/bin/sh
+# Changes the wallpaper to a randomly chosen image in a given directory
+# at a set interval.
 
-# This script will randomly go through the files of a directory, setting it
-# up as the wallpaper at regular intervals
-#
-# NOTE: this script is in bash (not posix shell), because the RANDOM variable
-# we use is not defined in posix
+DEFAULT_INTERVAL=300 # In seconds
 
-if [[ $# -lt 1 ]] || [[ ! -d $1   ]]; then
-	echo "Usage:
-	$0 <dir containing images>"
+if [ $# -lt 1 ] || [ ! -d "$1" ]; then
+	printf "Usage:\n\t\e[1m%s\e[0m \e[4mDIRECTORY\e[0m [\e[4mINTERVAL\e[0m]\n" "$0"
+	printf "\tChanges the wallpaper to a randomly chosen image in DIRECTORY every\n\tINTERVAL seconds (or every %d seconds if unspecified)." "$DEFAULT_INTERVAL"
 	exit 1
 fi
 
-# Edit below to control the images transition
-export SWWW_TRANSITION_FPS=60
-export SWWW_TRANSITION_STEP=2
-
-# This controls (in seconds) when to switch to the next image
-INTERVAL=300
+# See swww-img(1)
+RESIZE_TYPE="fit"
+export SWWW_TRANSITION_FPS="${SWWW_TRANSITION_FPS:-60}"
+export SWWW_TRANSITION_STEP="${SWWW_TRANSITION_STEP:-2}"
 
 while true; do
 	find "$1" -type f \
-		| while read -r img; do
-			echo "$((RANDOM % 1000)):$img"
-		done \
-		| sort -n | cut -d':' -f2- \
-		| while read -r img; do
-			swww img "$img"
-			sleep $INTERVAL
-		done
+	| while read -r img; do
+		echo "$(</dev/urandom tr -dc a-zA-Z0-9 | head -c 8):$img"
+	done \
+	| sort -n | cut -d':' -f2- \
+	| while read -r img; do
+		swww img --resize="$RESIZE_TYPE" "$img"
+		sleep "${2:-$DEFAULT_INTERVAL}"
+	done
 done

example_scripts/swww_randomize_multi.sh

@@ -1,73 +1,34 @@
-#!/bin/bash
+#!/bin/sh
+# For each display, changes the wallpaper to a randomly chosen image in
+# a given directory at a set interval.
 
-# This script will randomly go through the files of a directory,
-# setting a different random wallpaper for each display
-# at regular intervals
-#
-# NOTE: this script is in bash (not posix shell), because the RANDOM variable
-# we use is not defined in posix
+DEFAULT_INTERVAL=300 # In seconds
 
-if [[ $# -lt 1 ]] || [[ ! -d $1 ]]; then
-    echo "Usage:
-    $0 <dir containing images>"
-    exit 1
+if [ $# -lt 1 ] || [ ! -d "$1" ]; then
+	printf "Usage:\n\t\e[1m%s\e[0m \e[4mDIRECTORY\e[0m [\e[4mINTERVAL\e[0m]\n" "$0"
+	printf "\tChanges the wallpaper to a randomly chosen image in DIRECTORY every\n\tINTERVAL seconds (or every %d seconds if unspecified)." "$DEFAULT_INTERVAL"
+	exit 1
 fi
 
-# Make sure only 1 instance of swww_randomize
-PIDFILE=~/.local/state/swww-randomize-pidfile.txt
-if [ -e "${PIDFILE}" ]; then
-    OLD_PID="$(<${PIDFILE})"
-    if [ "X" != "X${OLD_PID}" -a -e "/proc/${OLD_PID}" ]; then
-        OLD_NAME="$(</proc/${OLD_PID}/comm)"
-        THIS_NAME="$(</proc/${BASHPID}/comm)"
-        if [ "${OLD_NAME}" = "${THIS_NAME}" ]; then
-            echo "old randomize process ${OLD_PID} is still running"
-            exit 1
-        else
-            echo "process with same ID as old randomize is running: \"${OLD_NAME}\"@${OLD_PID}"
-            echo "Replacing old process ID"
-        fi
-    fi
-fi
-echo "${BASHPID}" > ${PIDFILE}
-
-# Edit below to control the images transition
-export SWWW_TRANSITION_FPS=60
-export SWWW_TRANSITION_STEP=2
-
-# This controls (in seconds) when to switch to the next image
-INTERVAL=300
-
-# Possible values:
-#    -   no:   Do not resize the image
-#    -   crop: Resize the image to fill the whole screen, cropping out parts that don't fit
-#    -   fit:  Resize the image to fit inside the screen, preserving the original aspect ratio
+# See swww-img(1)
 RESIZE_TYPE="fit"
-
-DISPLAY_LIST=$(swww query | grep -Po "^[^:]+")
+export SWWW_TRANSITION_FPS="${SWWW_TRANSITION_FPS:-60}"
+export SWWW_TRANSITION_STEP="${SWWW_TRANSITION_STEP:-2}"
 
 while true; do
-    find "$1" -type f \
-        | while read -r img; do
-            echo "$RANDOM:$img"
-        done \
-        | sort -n | cut -d':' -f2- \
-        | tee ~/.local/state/swww-randomize-list.txt \
-        | while read -r img; do
-            # Set a different image for each display
-            for disp in $DISPLAY_LIST; do
-                # if there is no image try to get one
-                if [ "X" = "X${img}" ]; then
-                    if read -r img; then
-                        true
-                    else # if there are no more images, refresh the list
-                        break 2
-                    fi
-                fi
-                swww img --resize=$RESIZE_TYPE --outputs $disp $img
-                # make sure each image is only used once
-                img=""
-            done
-            sleep $INTERVAL
-        done
+	find "$1" -type f \
+	| while read -r img; do
+		echo "$(</dev/urandom tr -dc a-zA-Z0-9 | head -c 8):$img"
+	done \
+	| sort -n | cut -d':' -f2- \
+	| while read -r img; do
+		for d in $(swww query | grep -Po "^[^:]+"); do # see swww-query(1)
+			# Get next random image for this display, or re-shuffle images
+			# and pick again if no more unused images are remaining
+			[ -z "$img" ] && if read -r img; then true; else break 2; fi
+			swww img --resize "$RESIZE_TYPE" --outputs "$d" "$img"
+			unset -v img # Each image should only be used once per loop
+		done
+		sleep "${2:-$DEFAULT_INTERVAL}"
+	done
 done