每次装好Ubuntu，对于大多数用户来说，首先要做的事就是手动修改/etc/apt/sources.list文件，将里面的官方软件源地址更换为自己学校或者公司的软件源。当我们更换一个工作环境后，可能伴随着又要替换旧的软件源地址。
前者选出的是响应时间最优的，后者选出的是下载速度最快的。我们都知道软件源的作用是供客户端下载更新软件，所以当然是后者的方法更为准确，但笔者最终选择了前者作为测速方案，因为前者的用户体验更好且代码简单易懂。设想，如果我们采用后者，那么需要从每个软件源下载一个文件，并且这个文件不能太小，否则无法区分他们的速度，那么一个显而易见的情况是脚本需要运行较长的时间。
#!/bin/bash
#Program:
# This program gets the fastest ubuntu software sources from SOURCES_MIRRORS_FILE
# and backup update /etc/apt/sources.list
#Author: KJlmfe www.freepanda.me
#History:
# 2012/12/6 KJlmfe First release
VERSION="precise" # precise is code of Ubuntu 12.04 if your ubuntu is not 12.04 please change
TEST_NETCONNECT_HOST="www.baidu.com"
SOURCES_MIRRORS_FILE="sources_mirrors.list"
MIRRORS_SPEED_FILE="mirrors_speed.list"
function get_ping_speed() #return average ping $1 time
{
local speed=`ping -W1 -c1 $1 2> /dev/null | grep "^rtt" | cut -d '/' -f5`
echo $speed
}
function test_mirror_speed() #
{
rm $MIRRORS_SPEED_FILE 2> /dev/null; touch $MIRRORS_SPEED_FILE
cat $SOURCES_MIRRORS_FILE | while read mirror
do
if [ "$mirror" != "" ]; then
echo -e "Ping $mirror c"
local mirror_host=`echo $mirror | cut -d '/' -f3` #change mirror_url to host
local speed=$(get_ping_speed $mirror_host)
if [ "$speed" != "" ]; then
echo "Time is $speed"
echo "$mirror $speed" >> $MIRRORS_SPEED_FILE
else
echo "Connected failed."
fi
fi
done
}
function get_fast_mirror()
{
sort -k 2 -n -o $MIRRORS_SPEED_FILE $MIRRORS_SPEED_FILE
local fast_mirror=`head -n 1 $MIRRORS_SPEED_FILE | cut -d ' ' -f1`
echo $fast_mirror
}
function backup_sources()
{
echo -e "Backup your sources.list.n"
sudo mv /etc/apt/sources.list /etc/apt/sources.list.`date +%F-%R:%S`
}
function update_sources()
{
local COMP="main restricted universe multiverse"
local mirror="$1"
local tmp=$(mktemp)
echo "deb $mirror $VERSION $COMP" >> $tmp
echo "deb $mirror $VERSION-updates $COMP" >> $tmp
echo "deb $mirror $VERSION-backports $COMP" >> $tmp
echo "deb $mirror $VERSION-security $COMP" >> $tmp
echo "deb $mirror $VERSION-proposed $COMP" >> $tmp
echo "deb-src $mirror $VERSION $COMP" >> $tmp
echo "deb-src $mirror $VERSION-updates $COMP" >> $tmp
echo "deb-src $mirror $VERSION-backports $COMP" >> $tmp
echo "deb-src $mirror $VERSION-security $COMP" >> $tmp
echo "deb-src $mirror $VERSION-proposed $COMP" >> $tmp
sudo mv "$tmp" /etc/apt/sources.list
echo -e "Your sources has been updated, and maybe you want to run "sudo apt-get update" now.n";
}
echo -e "nTesting the network connection.nPlease wait... c"
if [ "$(get_ping_speed $TEST_NETCONNECT_HOST)" == "" ]; then
echo -e "Network is bad.nPlease check your network."; exit 1
else
echo -e "Network is good.n"
test -f $SOURCES_MIRRORS_FILE
if [ "$?" != "0" ]; then
echo -e "$SOURCES_MIRRORS_FILE is not exist.n"; exit 2
else
test_mirror_speed
fast_mirror=$(get_fast_mirror)
if [ "$fast_mirror" == "" ]; then
echo -e "Can't find the fastest software sources. Please check your $SOURCES_MIRRORS_FILEn"
exit 0
fi
echo -e "n$fast_mirror is the fastest software sources. Do you want to use it? [y/n] c"
read choice
if [ "$choice" != "y" ]; then
exit 0
fi
backup_sources
update_sources $fast_mirror
fi
fi
exit 0
