自己写的一些shell脚本

很贴心的猜价格的脚本

#!/bin/bash
PRICE=$(expr $RANDOM % 1000)
#PRICE=100
TIMES=10
USETIMES=0
LEFT=0
RIGHT=999
echo "商品的实际价格为0-999，猜猜看是多少？你最多有10次机会哦！"
while [[ $TIMES -gt 0 ]]    # [ $TIMES -gt 0 ]
do 
    read -p "请输入您猜测的价格数字（为一整数）： " INT
    let TIMES--
    let USETIMES++
    if [ $INT -eq $PRICE ];then
        echo "恭喜您答对了，实际价格是$PRICE"
        echo "您总共猜测了$USETIMES次"
        #TIMES=0
        break
    elif [ $INT -gt $PRICE ];then 
            RIGHT=$INT
            echo "猜高了！您还有$TIMES次机会，提示：价格位于$LEFT到$RIGHT之间。"
    else
        LEFT=$INT
        echo "猜低了！您还有$TIMES次机会，提示：价格位于$LEFT到$RIGHT之间。"
    fi
done

类C语言风格的bash shell脚本

#!/bin/bash
for ((integer=1;integer<=5;integer++))
do 
    echo "$integer"
done
echo "-------------------------"

sum=0
for ((i=1;i<=100;i=i+2))
do 
    let "sum+=i"
done
echo "sum=$sum"    
echo "------------------------"
LIMIT=5
for ((a = 1, b = 5;a <= LIMIT;a++,b--))
do 
    let "temp=a-b"
    echo "$a-$b=$temp"
done

AWK

BEGIN{
    for(n=1;n<=5;n++)
    print "2^"n,2**n
}
###awk   -f    for.awk     

[zengqingfu@zengqingfu ~]$ vim shell_scripts.sh 

[ -f aaaaa ]&&echo "aaaaa is a file" ||echo "aaaaa is a directory"
[ 10 -gt 10 ] && echo "10 is greater than 10" || echo "10 is not greater than 10"
echo $?
[ 10 -eq 10 ]
echo $?
FreeMem=`free -m | grep cache: |awk '{print $3}'`
echo $FreeMem

最后来个难一点的：用于回答问卷并判断结果的

[zengqingfu@zengqingfu shell_script]$ cat quiz 
#!/bin/bash
#remove the # on the following line to turn on debugging
#set -o xtrace

#==========================
function initialize (){
trap 'summarize;exit 0' INT    #Handle user interrupts
num_ques=0            #Number of questions asked so far
num_correct=0            #Number answered correctly so far 
first_time=true            #true until first question is asked
cd ${QUIZDIR:=~/quiz} || exit 2
}

#=========================
function choose_subj (){
subjects=($(ls))
PS3="Choose a subject for the quiz from the preceding list:"
select Subject in ${subjects[*]};do
    if [[ -z "$Subject" ]];then
    echo "No subject chosen. Bye." >&2
    exit 1
    fi
    echo $Subject
    return 0
done
}

#===========================
function exchange (){
temp_value=${questions[$1]}
questions[$1]=${questions[$2]}
questions[$2]=$temp_value
}

#===========================
function scramble (){
declare -i index quescount
questions=($(ls))
quescount=${#questions[*]}    #Number of elements
((index=quescount-1))
while [[ $index > 0 ]];do
    ((target=RANDOM % index))
    exchange $target $index
    ((index -= 1))
done
}

#==========================
function ask (){
exec 3<$1
read -u3 ques || exit 2
read -u3 num_opts || exit 2

index=0
choices=()
while (( index < num_opts )) ; do
    read -u3 next_choice || exit 2
    choices=("${choices[@]}" "$next_choice")
    ((index += 1 ))
done
read -u3 correct_answer || exit 2
exec 3<&-

if [[ $first_time = true ]];then
    first_time=false
    echo -e "You may press the interrupt key at any time to quit.
"
fi

PS3=$ques" "    #Make $ques the prompt for select
        #and add some spaces for legibility
select answer in "${choices[@]}";do
    if [[ -z "$answer"  ]];then
    echo "Not a valid choice.Please choose again."
    elif [[ "$answer" = "$correct_answer" ]];then
     echo 'Correct!'
    return 1
    else 
    echo "No,the answer is $correct_answer."
    return 0
    fi
done
}

#=========================
function summarize (){
echo             #skip a line
if ((num_ques == 0 ));then
    echo "You did not answer any questions"
    exit 0
fi

((percent=num_correct*100/num_ques))
echo "You answered $num_correct questions correctly,out of 
$num_ques total questions."
echo "Your score is $percent percent."
}

#============================
# main program
initialize        #Step 1 in top-level design

subject=$(choose_subj)   #Step 2
[[ $? -eq 0 ]] || exit 2   #If no valid choice,exit

cd $subject || exit 2     #Step 3
echo             #skip  a line
scramble         #step 4

for ques in ${questions[*]};do    #step 5
    ask $ques
    result=$?
    (( num_ques=numques+1 ))
    if [[ $result == 1 ]];then
    (( num_correct +=1 ))
    fi
    echo                     #skip a line between questions
    sleep ${QUIZDELAY:=1}
done


summarize                      #step 6
exit 0

[zengqingfu@zengqingfu shell_script]$ cd ..
[zengqingfu@zengqingfu ~]$ ll quiz/
总用量 40
drwxrwxr-x. 2 zengqingfu zengqingfu 4096 3月 17 10:23 art
drwxrwxr-x. 2 zengqingfu zengqingfu 4096 3月 17 10:25 biology
drwxrwxr-x. 2 zengqingfu zengqingfu 4096 3月 17 10:25 chemistry
drwxrwxr-x. 2 zengqingfu zengqingfu 4096 3月 17 10:25 Chinese
drwxrwxr-x. 2 zengqingfu zengqingfu 4096 3月 17 10:23 engineering
drwxrwxr-x. 2 zengqingfu zengqingfu 4096 3月 17 10:25 english
drwxrwxr-x. 2 zengqingfu zengqingfu 4096 3月 17 10:26 history
drwxrwxr-x. 2 zengqingfu zengqingfu 4096 3月 17 10:33 math
drwxrwxr-x. 2 zengqingfu zengqingfu 4096 3月 17 10:26 physics
drwxrwxr-x. 2 zengqingfu zengqingfu 4096 3月 17 10:24 politics

问题保存在脚本父目录的下面，分为好几类：

只要执行quiz脚本，制定好问题quiz所在的路径，脚本就能读取问题，然后你回答问题，而正确答案已经在问题的4个选项后面写好了，将你回答的与正确答案一比较，就能判断正误。