#!/bin/bash

# export DBUS_SESSION_BUS_ADDRESS environment variable useful when the script is set as a cron job

PID=$(pgrep gnome-session)

export DBUS_SESSION_BUS_ADDRESS=$(grep -z DBUS_SESSION_BUS_ADDRESS /proc/$PID/environ|cut -d= -f2-)

# $bing is needed to form the fully qualified URL for

# the Bing pic of the day

bing="cn.bing.com"

# $xmlURL is needed to get the xml data from which

# the relative URL for the Bing pic of the day is extracted

#

# The mkt parameter determines which Bing market you would like to

# obtain your images from.

# Valid values are: en-US, zh-CN, ja-JP, en-AU, en-UK, de-DE, en-NZ, en-CA.

#

# The idx parameter determines where to start from. 0 is the current day,

# 1 the previous day, etc.

xmlURL="-d 'format=xml&idx=0&n=1&mkt=zh-CN' --get  http://cn.bing.com/HPImageArchive.aspx"

# $saveDir is used to set the location where Bing pics of the day

# are stored.  $HOME holds the path of the current user's home directory

saveDir="$HOME/Pictures/Bing/"

# Create saveDir if it does not already exist

mkdir -p $saveDir

# Set picture options

# Valid options are: none,wallpaper,centered,scaled,stretched,zoom,spanned

picOpts="zoom"

# The desired Bing picture resolution to download

# Valid options: "_1024x768" "_1280x720" "_1366x768" "_1920x1200"

desiredPicRes="_1920x1200"

# The file extension for the Bing pic

picExt=".jpg"

# Extract the relative URL of the Bing pic of the day from

# the XML data retrieved from xmlURL, form the fully qualified

# URL for the pic of the day, and store it in $picURL

# Form the URL for the desired pic resolution

desiredPicURL=$bing$(echo $(curl  $xmlURL) | grep -oP "<urlBase>(.*)</urlBase>" | cut -d ">" -f 2 | cut -d "<" -f 1)$desiredPicRes$picExt

# Form the URL for the default pic resolution

defaultPicURL=$bing$(echo $(curl  $xmlURL) | grep -oP "<url>(.*)</url>" | cut -d ">" -f 2 | cut -d "<" -f 1)

# $picName contains the filename of the Bing pic of the day

# Attempt to download the desired image resolution. If it doesn't

# exist then download the default image resolution

if wget --quiet --spider "$desiredPicURL"

then

    # Set picName to the desired picName

    picName=${desiredPicURL##*/}

    # Download the Bing pic of the day at desired resolution

    curl -s -o $saveDir$picName $desiredPicURL

else

    # Set picName to the default picName

    picName=${defaultPicURL##*/}

    # Download the Bing pic of the day at default resolution

    curl -s -o $saveDir$picName $defaultPicURL

fi

# Set the GNOME3 wallpaper

gsettings set org.gnome.desktop.background picture-uri "file://$saveDir$picName"

# Set the GNOME 3 wallpaper picture options

gsettings set org.gnome.desktop.background picture-options $picOpts

# Remove pictures older than 30 days

#find $saveDir -atime 30 -delete

# Exit the script

exit

# To define the time you can provide concrete values for

# minute (m), hour (h), day of month (dom), month (mon),

# and day of week (dow) or use '*' in these fields (for 'any').#

# Notice that tasks will be started based on the cron's system

# daemon's notion of time and timezones.

#

# For example, you can run a backup of all your user accounts

# at 5 a.m every week with:

# 0 5 * * 1 tar -zcf /var/backups/home.tgz /home/

#

# m h  dom mon dow   command

15 1 * * * /home/kuizhi/program/bingWallPaper.sh