[转]bing壁纸天天换 初识shell魅力

原文链接：http://www.cnblogs.com/atskyline/p/3679522.html

　　原文的程序跑在window上，curl的使用不太一样，想要获取的图片也不太一样。修改后的代码如下：

#!/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

　　然后用crontab，做成每日任务，就可以天天换bing壁纸了。crontab代码如下：

# 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