01.读<>清系统日志程序

############################start ###########################

#!/bin/bash
#cleanup

LOG_DIR=/var/log
ROOT_UID=0  
LINES=50
E_XCD=66
E_NOTROOT=67

if [ "$UID" -ne "$ROOT_UID" ]
then
 echo "must be root to run this script."
 exit $E_NOTROOT
fi

 

if [ -n "$1" ]
 then
   lines=$1
 else
   lines=$LINES
fi

 

cd $LOG_DIR
if [ `pwd` != "$LOG_DIR" ]
 then
   echo "can't change to $LOG_DIR."
   exit $E_XCD

fi

 

tail -$lines messages > mesg.temp
mv mesg.temp messages

cat /dev/null > wtmp
echo "Logs cleaned up."

exit
######################end ######################