changer.sh

#!/bin/bash
#####################################################
## use this script with crontab and some global keyboard shortcut
## commands to `sed` its 18th line  (by some script)
## and enjoy your best wallpapers
## BY MOSAID
#####################################################
####                                   directories                                      ####
#####################################################
D0="/media/mosaid/My_Data/Images"                                 # alt H
D1="$D0/collectionWallpapers"                                            # alt G
D2="$D0/001 images/wallhaven/myBackgrunds"                # alt F
D3="$D0/001 images/wallhaven/bg0s"
D4="/home/mosaid/Pictures/wallhaven/myBackgrunds"
D5=""
D6=""
#####################################################
DIR=$D0               ### changed by global keyboard shortcuts
#####################################################
DIRECTORY="/media/mosaid/WindowsDir/Users/mosaid/GoogleDrive/linux/scripts0/wallp"
PREV="$DIRECTORY/.prev"
IMAGES="$DIRECTORY/.wlist"
FAV="$DIRECTORY/.fav"
NOTES="$DIRECTORY/.notes"
LAST="$DIRECTORY/.last"
#####################################################
function printhelp () {
    string1=$1
    string2=$2
    pad=$( printf '%0.1s' " "{1..60} )
    padlength=25
    printf '\t%s' "$string1"
    printf '%*.*s' 0 $(( padlength - ${#string1}  )) "$pad"
    printf '%s\n' "$string2"
}
function selectPIC () {
   PIC=$( find "$DIR/" -type f -printf "%p\n" | shuf -n1 )
   if  grep -w "$PIC"  "$PREV" >/dev/null
        then return 0  # $PIC is found in history
   fi
   tmp=$(dirname "$PIC" )
   if  grep -w "$tmp"  "$IMAGES" >/dev/null
     then return 1  # $DIR is listed in $IMAGES
     else return 0  # $DIR not listed in $IMAGES
   fi
}
#####################################################
####                            handle the args                                     ####
#####################################################
case  "$1"  in
    "a" | "-a" | "--appearance"   )  # mate appearance properties
        mate-appearance-properties >/dev/null 2>&1 &
        ;;
    "p" | "-p" | "--previous" )  #previous wallpaper
        if [ "$DIR" == "" ] ; then
                SF=$( cat "$FAV" | wc -l )
                LF=$( cat "$LAST" )
                let " LF = LF - 1 "
                if (( $LF <= 1 )) ; then LF=$SF ; fi
                PIC=$(  sed  -n "$LF"p  "$FAV"  )
                echo "$LF" > "$LAST"
            else
                PIC=$(cat $PREV | tail -2 |sed -n "1p" )
        fi
        sed -i '$ d' $PREV
        truncate -s -1 $PREV
        ;;
    "c" | "-c" | "--current" )  #print path to current wallpaper
        PIC=$(cat $PREV | tail -1 )
        echo "$PIC"
        ;;
    "o" | "-o" | "--open"  )  #open  current wallpaper
        PIC=$(cat $PREV | tail -1 )
        gnome-open "$PIC"
        ;;
    "f" | "-f" | "--fav"  )  # add current wallpaper to favourites
        PIC=$(cat $PREV | tail -1 )
        L=$( cat "$FAV"  | grep -n "$PIC" | cut -f1 -d: | head -n 1 )
        re='^[0-9]+$'
        if  !  [[ $L =~ $re ]] ; then echo "$PIC" >> $FAV ; else echo "already a favourite" ; fi
        ;;
    "r" | "-r" | "--remove"  )  #remove current wallpaper from favourites"
        PIC=$(cat $PREV | tail -1 )
        L=$( cat "$FAV"  | grep -n "$PIC" | cut -f1 -d: | head -n 1 )
        re='^[0-9]+$'
        if  [[ $L =~ $re ]] ; then   sed -i  "$L"d "$FAV" ; else echo "not a favourite" ; fi
        ;;
    "n" )   #save a note about current wallpaper
        if [ -z "$2"  ] ; then
            echo "usage : `basename $0`  < n >  < note > "
            else
            PIC=$(cat $PREV | tail -1 )
            echo "" >>"$NOTES"
            echo "$2" >>"$NOTES"
            echo "$PIC" >>"$NOTES"
        fi
        ;;
    "nn" | "notes" | "--notes" )
        cat "$NOTES"
        ;;
    "-h" | "h" | "help" | "--help" )
        printhelp "h, -h, --help" "print this help"
        printhelp "" "next wallpaper"
        printhelp "a, -a, --appearance" "mate appearance"
        printhelp "p, -p, --previous"  "previous wallpaper"
        printhelp "c, -c, --current" "print path to current wallpaper"
        printhelp "o, -o, --open" "gnome open current wallpaper"
        printhelp "f, -f, --fav"  "add current wallpaper to favourites"
        printhelp "r, -r, --remove" "remove current wallpaper from favourites"
        printhelp "n [note]"    "save a note about current wallpaper"
        printhelp "nn, notes, --notes"  "print saved notes"
        ;;
    "" )  # no aguments , next wallpaper
            if [ "$DIR" == "" ]
                then      #select pic from favourites
                        LF=$( cat "$LAST" )
                        SF=$( cat "$FAV" | wc -l )
                        let " LF += 1"
                        if (( $LF > $SF )) ; then LF=1 ; fi
                        echo "$LF" > "$LAST"
                        PIC=$(  sed  -n "$LF"p  "$FAV"  )
                else     #select random pic from $DIR preferably not previously used  and $DIR is listed in $IMAGES
                            result=0
                            count=0
                            while [ $result == 0 ] && (( $count < 20 )) ; do
                                    selectPIC
                                    result=$?
                                    let " count += 1 "
                            done
            fi
            printf "\n$PIC" >> $PREV   # save pic in history
        ;;
    * ) # default
        echo "command not recognized use --help"
        ;;
esac
#####################################################
PID=$(pgrep mate-session)
export DBUS_SESSION_BUS_ADDRESS=$(grep -z DBUS_SESSION_BUS_ADDRESS /proc/$PID/environ|cut -d= -f2-)
#####################################################
###             go ahead if $PIC is a valid image file                       ###
#####################################################
if `file "$PIC" | grep -w image >/dev/null`  ; then
    gsettings set org.mate.background picture-filename "$PIC"
    dim=$( identify -format '%w  %h' "$PIC"  )
    dim=( $dim )
    if ((  ${dim[0]} <= 1920 )) && ((  ${dim[1]} <= 1080 ))
        then option='stretched'
        else option='scaled'
    fi
    gsettings set org.mate.background picture-options "$option"
fi
#####################################################
####                         truncate history                                        ####
#####################################################
SIZE=100
length=$(cat $PREV | wc -l)
if (( $length > $SIZE )) ; then
    let " length = length - $SIZE "
    sed  -i "1,$length"d $PREV
fi
##################  THE END    ########################