ubuntu 一键换源 bash

手动指定源链接，一键替换

#!/bin/bash
# do not exit, copy a backup
SRC_DIR="/etc/apt/sources.list"
SRC_DIR_OLD="/etc/apt/sources.list.old"
if [ ! -f $SRC_DIR_OLD ]; then
    echo "first time run this script, backup the sources.list"
    cp $SRC_DIR $SRC_DIR_OLD
else
    echo "restore the sources.list"
    cp $SRC_DIR_OLD $SRC_DIR
fi
read -p "Paste the ubuntu src:(Enter to exit)" UB_NEW_SRC
if test -z "$UB_NEW_SRC"; then
    echo "do not enter a new src, exit"
    exit
fi
sed "s#`cat $SRC_DIR | sed "s/^deb \(.*\) .* main .*/\1/p" -n | head -n 1`#$UB_NEW_SRC#g" -i $SRC_DIR
cat $SRC_DIR | grep $UB_NEW_SRC | head -n 1
#apt update