Shell Script Forloops

1. Determine the type of all files in the/var/directory

for files in   /var/* ;do    if [[ -f $files ]];then        echo "$files exists and is a regular file."    elif [[ -h $files ]] ;then        echo "$files is a symbolic link."    elif [[ -d $files ]] ;then        echo "$files is a directory."    else        echo "$files is others."    fidone

2, add 10 user user1-user10, password is 8 bit random characters

for user in user{1..10} ;do    id $user &> /dev/null    if [[ $? -ne 0 ]] ;then        useradd $user#openssl rand -base64 6  ; uuidgen |cut -c8        pw=`openssl rand -base64 6`        echo  $pw|passwd --stdin  $user &> /dev/null        echo "user:$user, password : $pw" >> /root/pw_file    else        echo "Error:$user is exsit"        exit    fi    if [ $user == "user10" ] ;then        echo "user is created,password is in  /root/pw_File"                                                                                                               fidone

#删除10个用户
for i in {1..10} ;do userdel -r user$i ;done

3. The/ETC/RC.D/RC3.D directory has several files starting with K and beginning with S, respectively reading each file, the output starting with K is the file plus stop, the output starting with S is the filename plus start, such as K34filename stop S66filename Start

for files in /etc/rc.d/rc3.d/[KS]* ;do    if [ `basename $files|cut -c1` == "K" ] ;then        echo "$files stop"    else        echo "$files start"                                                                                                                                                fidone

4, write the script, prompt to enter the value of positive integer n, calculate the sum of 1+2+...+n

read -p "please input a positive integer: " INTif [[ $INT =~ ^[0-9]+$ ]] && [[ `expr $INT` != 0 ]] ;then    sum=0    for i in `seq $INT`;do        let sum+=i    done    echo "sum=$sum"else    echo "Error:your input is not positive integer"fi

5. Calculates the sum of all integers within 100 that can be divisible by 3

sum=0for i in `seq 3 3 100` ;do    let sum+=idoneecho "sum=$sum"

for((i=3,sum=0; i<=100; i+=3,sum+=i));do    echo -n                                                                                                                                                            doneecho "sum:$sum"

6, write a script, prompted to enter the network address, such as 192.168.0.0, determine the input network segment of the host online status

read -p "please input IP:" IPIPC=`echo $IP |awk -F. ‘$1=255&&$2<=255&&$3<=255&&$4<=255{print "0"}‘`IPCHECK=`echo $IP |grep -Eo "^[0-9]{1,3}\.[0-9]{1,3}\."`if echo $IP |grep -E "^[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}$" ;then    echo "start>>>" >>/root/ipup.txt    if [ $IPC -eq 0 ] ;then        for IP1 in {0..254} ;do            for IP2 in `seq 254`;do                {                ping -c1 -w1  $IPCHECK$IP1.$IP2 &> /dev/null                [ $? -eq 0 ] && echo "The host $IPCHECK$IP1.$IP2  run up" >> /root/ipup.txt                }&            done            wait        done    else        echo "your IP $IP is not available"    fielse    echo "your IP $IP format is wrong"fi

7. Print 99 multiplication table

for i in {1..9};do    for j in `seq $i`;do        echo -en "$i*$j=$(($i*$j))\t"    done    echodone

8, create 10 HTML files in the/testdir directory, the file name format is the number n (from 1 to 10) plus a random 8 letters, such as: 1abcdefgh.html

for i in {1..10};do    NUM=`openssl rand -base64 6|tr -dc ‘[:alpha:]‘ |head -c10`    touch /data/${i}${NUM}.htmldoneunset NUM

9. Print Isosceles triangle

read -p "please input the triangle number: " NUMfor n in `seq $NUM` ;do{    for a in `seq $[$NUM-$n]` ;do        echo -n " "    done    for b in `seq $[2*$n-1]` ;do        color=$[RANDOM%7+31]        echo -en  "\033[1;${color}m*\033[0m"    done    echo}&done

Shell Script Forloops