shell小案例

#!/bin/bash

if [ -f /path/to/a.pid ];

then 
num=$(cat /path/to/a.pid)

kill -9 $num

else

echo "have no pid,make sure app have running!"
fi


cat tables|while read node do echo "node : $node" /usr/local/hive/bin/hive -e "describe $node" >> $node.txtawk '{print $1,$2","}'  $node.txt>>$node.txt1echo "#!/bin/bash " >>$node.sh echo "source ../../config/set_env.conf" >>$node.sh  echo "\$HIVE << EOF " >>$node.sh echo "drop table $node;" >>$node.sh echo "CREATE EXTERNAL TABLE $node(" >>$node.sh  cat $node.txt1>>$node.sh echo ")">>$node.sh   echo "ROW FORMAT DELIMITED FIELDS TERMINATED BY '\,' LINES TERMINATED BY '\n'">>$node.sh   echo "STORED AS textfile ">>$node.sh   echo "location '/user/hadoop/idap/base/';">>$node.sh   echo "alter table $node set serdeproperties('serialization.null.format' = '');">>$node.sh  #echo "LOAD DATA INPATH \"/user/hadoop/idap/base/$node.txt\" INTO TABLE $node; ">>$node.sh echo "exit;">>$node.sh   echo "EOF">>$node.sh   echo "if [ $? -ne 0 ];then">>$node.sh   echo "      exit 2">>$node.sh   echo "fi">>$node.sh    rm $node.txtrm $node.txt1echo "================"done