shell语句

一、判断目录是否存在：
#!/bin/bash
#/bin/bash -n filename.sh 判断语句是否正确

DIR=/root/zhj
if [ ! -d $DIR ];then

mkdir $DIR

echo "$DIR create suecces"
else
echo "$DIR is exist,please exst"
fi
#--------------------------------------------
二、多条件语句
#!/bin/bash
scores=$1
if [ -z $scores ];then
echo "please scores "
exit
fi
if [[ $scores -gt 90 ]];then
echo "vare good"
elif [[ $scores -gt 80 ]];then
echo "good"
elif [[ $scores -gt 60 ]];then
echo "pass"
else
echo "no pass"
fi
#---------------------------------------------

#判断文件是否存在

#!/bin/bash

FILENAME=/root/filename

if [ -f $FILENAME ] ;then

        echo "$FILENAME is exist .please exit"

        ccho "my filename" >> $FILENAME

else

        touch /root/filename

        echo "$FILENAME create success"

#!/bin/bash

FILENAME=/root/filename

if [ -f $FILENAME ] ;then

        echo "$FILENAME is exist .please exit"

        echo "my filename" >> $FILENAME

else

        touch /root/filename

        echo "$FILENAME create success"

fi