Shell 把一个数据库中所有表的描述写到一个文件里

#!/bin/sh

tables=`mysql -u root -e "use i_test;show tables;"`

for list in $tables
do
    if [ $list == 'Tables_in_i_test' ];
    then
	   echo "Table in i_test:" >> a.txt
    else
	   echo >>a.txt
	   echo TABLE "["$list"]" DESCRIBE:>>a.txt
	   mysql -u root -t -e"desc i_test.$list" |tee -a a.txt
    fi
done