pshot

#!/bin/bash

# pshot by anvornial
# take screenshot of x desktop periodically using scrot
# dependency : scrot, md5sum, find, shuf, convert (imagemagick, optional)

function _display_help {
    echo ""
    echo "pshot"
    echo "  take screenshot of X desktop periodically using scrot"
    echo ""
    echo "usage : "
    echo "  $0 [option] [save location]"
    echo 
    echo "option :"
    echo " -q [quality] "
    echo "  jpeg output quality, value is 1 to 100. Default is 20"
    echo 
    echo " -d [range_low-range_high]"
    echo "  Delay between each screenshot. Using range like 5-45, it means, delay will vary between 5 to 45 seconds."
    echo "  Fixed delay can be achived with same number in range like 50-50."
    echo "  Default is 5-45"
    echo 
    echo " -n  "
    echo "  Disable annotation bar. By default, each image will contain annotation using"
    echo "  'convert' from imagemagick, if installed."
    echo
    echo " -h --help"
    echo "  Display this help"
    echo
    echo " --"
    echo "  Stop args parsing"
}


if [[ $1 == "" || " $@ " == *\ -h\ * || " $@ " == *\ --help\ * ]]; then
    _display_help
    exit
fi

# renice ourself
renice -n 19 $$ &> /dev/null

# main variable
RANGE="5-45"
QUALITY=20
CONVERT=$(command -v convert)
TMPDIR=$(mktemp -d /tmp/outputpshot.XXXXXXXXXX)
if [[ ! -d "$TMPDIR" ]]; then
    echo "ERROR cannot create temporary directory"
    exit 1
fi

# trap function
function _revert {
    # clean temp directory
    if [[ -d "$TMPDIR" ]]; then 
        rm -rf "$TMPDIR"
    fi
    exit
}
trap _revert HUP INT TERM EXIT

# begin parsing command
while [[ $1 == -* ]]; do
    if [[ $1 == "-q" ]]; then
        shift
        if (( $1 >= 5 && $1 <= 100 )); then
            QUALITY="$1"
        else
            echo "ERROR invalid quality value : $1, must be between 5 to 100"
            exit
        fi
    elif [[ $1 == "-d" ]]; then
        shift
        RANGE="$1"
        # test if delay is valid
        shuf -i $RANGE -n 1 > /dev/null 2>&1
        if [[ $? != "0" ]]; then
            echo "ERROR invalid delay range : $1"
            exit
        fi
    elif [[ $1 == "-n" ]]; then
        CONVERT=""
    elif [[ $1 == "--" ]]; then
        shift
        break
    fi
    shift
done

# check location path
if [[ -d "$1" ]]; then
    LOCATION=$(realpath "$1")
else   
    echo "ERROR invalid save location on '$1'"
    exit
fi

# main script loop
while :; do
    # get screenshot
    cd "$TMPDIR"
    if [[ $CONVERT != "" ]]; then
        CUR_FILE=($(scrot -m -z 'pshot__%Y-%m-%d__%H_%M_%S.png' -e 'md5sum $f'))
    else
        CUR_FILE=($(scrot -m -z -q $QUALITY 'pshot__%Y-%m-%d__%H_%M_%S.jpg' -e 'md5sum $f'))
    fi

    # save screenshot
    if [[ -f "${CUR_FILE[1]}" ]]; then
        if [[ "${CUR_FILE[0]}" == "$PREV_HASH" ]]; then   
            echo "same image detected, not saving"
            rm "${CUR_FILE[1]}"
        else
            if [[ -d "$LOCATION" ]]; then
                LOCATION_WITH_DATE="$LOCATION/$(date '+%Y')/$(date '+%Y-%m-%d')"
                [[ ! -d "$LOCATION_WITH_DATE" ]] && mkdir -p "$LOCATION_WITH_DATE"
                if [[ -d "$LOCATION_WITH_DATE" ]]; then
                    if [[ $CONVERT != "" ]]; then
                        SAVEPATH="$LOCATION_WITH_DATE/${CUR_FILE[1]%.*}.jpg"
                        $CONVERT "${CUR_FILE[1]}" \
                            -quality $QUALITY \
                            -gravity South -background Gold -splice 0x30 \
                            -pointsize 20 -gravity SouthWest -annotate 0 "pshot $(whoami)@$(hostname)    $(date '+%A %B %d %Y %z') $(uptime)" \
                            "$SAVEPATH"
                        rm "${CUR_FILE[1]}"
                    else
                        SAVEPATH="$LOCATION_WITH_DATE/${CUR_FILE[1]}"
                        cp "${CUR_FILE[1]}" "$SAVEPATH"
                        rm "${CUR_FILE[1]}"
                    fi
                    echo "screenshot saved to $SAVEPATH"
                fi
            fi
        fi
    fi
    PREV_HASH=${CUR_FILE[0]}

    # random delay with range
    DELAY=$(shuf -i $RANGE -n 1)
    echo "next screenshot in $DELAY seconds"
    sleep $DELAY
done