简单shell题

1.
#!/bin/bash
#
FI="/bin/data"
if `cat $FI &> /dev/null`;then
echo "$FI is exist"
else
echo "$FI no found!"
exit 88
fi

2.
#!/bin/bash
#
HH=`date +%H`
echo "Now Time:" `date +%H:%M:%S`
case $HH in
  00|01|02|03|04|05|06|07|08|09|10|11)
echo "Good Morning!"
  ;;
  12|13|14|15|16|17)
echo "Good Afternoon!"
  ;;
  18|19|20|21|22|23)
echo "Good Evening!"
  ;;
  *)
  ;;
esac

3.
#!/bin/bash
#
read -p "Please input the username" US

until who | grep $US &> /dev/null;do
echo $US "is not come"
sleep 10
done

echo $US "is loging ..."

4.
#!/bin/bash
#
declare Par
function message(){
echo "0.echo hello,world!"
echo "1.echo hi!"
echo "2.quit"
read -p "Please input parameter" Par
}
message
while [ $Par <> '2' ] ; do
  case $Par in
0)
echo "hello,world"
;;
1)
echo "hi,world"
;;
2)
exit 88
;;
*)
echo "Unkown command"
;;
  esac
  sleep 2
  message
done

5.
#!/bin/bash
#
declare Dir
read -p "Please input directory" Dir
for i in `ls $Dir/*.txt` ;do
j=`echo $i|cut -d. -f1`".doc"
mv $i $j
done

6.
#!/bin/bash
#
read -p "Please input the username" US

until who | grep $US &> /dev/null;do
echo $US "is not come"
sleep 300
done
echo $US "is loging ..."
who|grep $US

rolay8

#!/bin/bash
file=/bin/date
if [ -f $file ];then
echo "file exist!"
else
echo "no file!,please check!"
fi

rolay8

#!/bin/bash
nowtime=`date +"%H"`
if [[ 0 -le $nowtime && $nowtime -lt 12 ]];then
echo "good morning!"
elif [[ 12 -le $nowtime && $nowtime -lt 18 ]]; then
echo "good afternoon！"
elif [[ 18 -le $nowtime && $nowtime -ge 23 ]]; then
echo "good night!"
fi

Remember犬牙

回复看答案？

rolay8

#!/bin/bash
loginuser=`who|awk '{print $1}'`
result=`echo $loginuser|grep $1`
if [[ -n $result ]];then
echo "$1 is here!"
else
echo "$1 is not here!"
fi

2.#! /bin/sh -
hour=`date|cut –c 12-13`
if test “$hour” –ge 0 –a “$hour” –le 11; then
echo “Good morning!”
elif test “$hour” –ge 12 –a “$hour” –le 17; then
echo “Good afternoon!”
else
echo “Good evening!”
fi

? 说明：
第一个有效语句是将命令执行的结果赋给hour变量，所以用反向单引
号。
用cut命令从date命令的输出中切割出“小时”信息；这里-c 10-11
选项表示只切割10到11列。
这个程序使用了if连用格式，也可以使用if完整格式的嵌套形式。
②根据系统当前的时间向用户输出问候信息

3. #!/bin/bash

echo 'type in the user name:'
read user

if grep $user /etc/passwd > /tmp/null && who | grep $user
# 测试条件是由&&连接的2个命令

# grep $user /etc/passwd > /tmp/null ,从/etc/passed文件中寻找$user字段，并重定向输出到文件/tmp/null

# who | grep $user ,who命令列出当前系统已经登录的用户，管道|链接，从其中寻找是否有$user字符串

then
echo "$user has logged in the system."
cp /tmp/null ~/me.tmp
rm /tmp/null
else
echo "$user has not logged in the system."
fi

4. #! /bin/sh
clear
echo "-------------MENU---------"
echo
echo "1.Find files modified in last 24 hours"
echo "2. The free disk space"
echo "3. Space consumed by this user"
echo "4.Exit"
echo
echo -n " Select:"
read choice
case $choice in
1)find $HOME -mtime -1 -print;;
2)df;;
3)du -s $HOME;;
4)exit;;
*)echo "Invalid option"
esac

5. #!/bin/sh
for file in *.txt
do
leftname=`basename $file .txt`
mv $file $leftname.doc
done

说明：
（1）在Linux系统中不支持mv *.txt *.doc这样的更名命令形式
，如果需要将文件成批地更名最好编写一个shell脚本文件。
（2）在for语句的参数列表中使用了“*”通配符。
（3（在程序中用到basename命令，该命令从随后的文件名剥去指
定的后缀。
⑤将当前目录下所有的.txt文件更名

6.方法一：

#!/bin/bash

read -p "Enter a user name: " userName

先判别用户名是否存在

while ! id $userName &> /dev/null; do

read -p "Enter a user name again: " userName

done

who | grep "^$userName" &> /dev/null

retVal=$?

while [ $retVal -ne 0 ]; do

sleep 300

who | grep "^$userName" &> /dev/null

retVal=$?

done

echo "$userName is on."

1.#!/bin/bash
file=/bin/date
if [ -f $file ]
then
echo "$file cun zai"
else
echo "wen jian bu cun zai"
fi

2. #!/bin/bash
time=`date +%T |awk -F ':' '{print $1}'`
if [[ $time -ge 0 && $time -lt 12 ]]
then
echo "good morning"
elif [[ $time -ge 12 && $time -lt 18 ]]
then
echo "good afternoon"
else
echo "good night"
fi

3.#!/bin/bash
if [ $# -le 0 ]
then
echo "zhi xing shi qing shu ru yonghu"
exit 0
fi
if [ $# -ge 1 ]
then
for i in $@
do
us=`who |grep $i`
if [ $? == 0 ]
then
echo "$us"
else
echo " $i wei deng lu "
fi
done
fi