Article directory
21, download files from FTP server
22, five consecutive numbers within an input 100, and statistics, the minimum and maximum
23, the results are assigned to the variable
24, modify the batch file name
25, the statistics in the current directory ending in .html file always great
26, scan host port status
27, Expect interaction-free implementation of the SSH command execution
28, batch modify server user password
29, print multiplication formulas
30, getopts tool perfect script command-line arguments
21, download files from FTP server
#!/bin/bash
if [ $# -ne 1 ]; then
echo "Usage: $0 filename"
be
dir=$(dirname $1)
file=$(basename $1)
ftp -n -v << EOF # -n automatic login
open 192.168.1.10 # ftp server
user admin password
binary # Set ftp binary transfer mode, to avoid the MD5 value different compressed format error or .tar.gz
cd $ dir
get "$file"
EOF
22, five consecutive numbers within an input 100, and statistics, the minimum and maximum
#!/bin/bash
COUNT=1
SUM=0
MIN = 0
MAX=100
while [ $COUNT -le 5 ]; do
read -p "Enter integer less than 100:" INT
if [[ ! $INT =~ ^[0-9]+$ ]]; then
echo "input must be an integer!"
exit 1
elif [[ $INT -gt 100 ]]; then
echo "input must be less than 100!"
exit 1
be
SUM=$(($SUM+$INT))
[ $MIN -lt $INT ] && MIN=$INT
[ $MAX -gt $INT ] && MAX=$INT
let COUNT++
done
echo "SUM: $SUM"
echo "MIN: $MIN"
echo "MAX: $MAX"
23, the results are assigned to the variable
Scenario: assigning an execution result or a desired position to the variable parameter, for subsequent use.
method 1:
for i in $(echo "4 5 6"); do
eval a$i=$i
done
echo $ $ a4 a5 $ a6
Method 2: The position parameter 192.168.1.1 {1,2} to split each variable
a = 0
for i in $ (eval echo $ *); do #eval be decomposed into {1,2} 12
let num+=1
eval node${num}="$i"
done
echo $node1 $node2 $node3
# bash a.sh 192.168.1.1{1,2}
192.168.1.11 192.168.1.12
Method 3:
arr=(4 5 6)
INDEX1=$(echo ${arr[0]})
INDEX2=$(echo ${arr[1]})
INDEX3=$(echo ${arr[2]})
24, modify the batch file name
Example:
# touch article_{1..3}.html
# ls
article_1.html article_2.html article_3.html
Objective: To read the article bbs
method 1:
for file in $(ls *html); do
mv $file bbs_${file#*_}
# mv $file $(echo $file |sed -r 's/.*(_.*)/bbs\1/')
# mv $file $(echo $file |echo bbs_$(cut -d_ -f2)
done
Method 2:
for file in $(find . -maxdepth 1 -name "*html"); do
mv $file bbs_${file#*_}
done
Method 3:
# rename article bbs *.html
25, the statistics in the current directory ending in .html file always great
method 1:
# find . -name "*.html" -exec du -k {} \; |awk '{sum+=$1}END{print sum}'
Method 2:
for size in $(ls -l *.html |awk '{print $5}'); do
sum=$(($sum+$size))
done
echo $sum
26, scan host port status
#!/bin/bash
HOST=$1
PORT="22 25 80 8080"
for PORT in $PORT; do
if echo &>/dev/null > /dev/tcp/$HOST/$PORT; then
echo "$PORT open"
else
echo "$PORT close"
be
done
27, Expect interaction-free implementation of the SSH command execution
Expect interactive application is an automated tool, such as telnet, ftp, passwd like.
You need to install expect the package.
Method 1: EOF expect as a standard input standard output
#!/bin/bash
USER=root
PASS=123.com
IP=192.168.1.120
expect << EOF
set timeout 30
spawn ssh $USER@$IP
expect {
"(yes/no)" {send "yes\r"; exp_continue}
"password:" {send "$PASS\r"}
}
expect "$USER@*" {send "$1\r"}
expect "$USER@*" {send "exit\r"}
expect eof
EOF
Method 2:
#!/bin/bash
USER=root
PASS=123.com
IP=192.168.1.120
expect -c "
spawn ssh $USER@$IP
expect {
\"(yes/no)\" {send \"yes\r\"; exp_continue}
\"password:\" {send \"$PASS\r\"; exp_continue}
\"$USER@*\" {send \"df -h\r exit\r\"; exp_continue}
}"
Method 3: expect scripts independent
Login script:
# cat login.exp
#!/usr/bin/expect
set ip [lindex $argv 0]
set user [lindex $argv 1]
set passwd [lindex $argv 2]
set cmd [lindex $argv 3]
if { $argc != 4 } {
puts "Usage: expect login.exp ip user passwd"
exit 1
}
set timeout 30
spawn ssh $user@$ip
expect {
"(yes/no)" {send "yes\r"; exp_continue}
"password:" {send "$passwd\r"}
}
expect "$user@*" {send "$cmd\r"}
expect "$user@*" {send "exit\r"}
expect eof
Run the script: write cycles can operate multiple batch servers
#!/bin/bash
HOST_INFO=user_info.txt
for ip in $(awk '{print $1}' $HOST_INFO)
do
user=$(awk -v I="$ip" 'I==$1{print $2}' $HOST_INFO)
pass=$(awk -v I="$ip" 'I==$1{print $3}' $HOST_INFO)
expect login.exp $ip $user $pass $1
done
Linux host SSH connection information:
# cat user_info.txt
192.168.1.120 root 123456
28, batch modify server user password
Linux host SSH connection information: the old password
# cat old_pass.txt
192.168.18.217 root 123456 22
192.168.18.218 root 123456 22
Content format: IP User Password Port
SSH Remote Change Password script: new randomly generated password
#!/bin/bash
OLD_INFO=old_pass.txt
NEW_INFO=new_pass.txt
for IP in $(awk '/^[^#]/{print $1}' $OLD_INFO); do
USER=$(awk -v I=$IP 'I==$1{print $2}' $OLD_INFO)
PASS=$(awk -v I=$IP 'I==$1{print $3}' $OLD_INFO)
PORT=$(awk -v I=$IP 'I==$1{print $4}' $OLD_INFO)
NEW_PASS = $ (mkpasswd -l 8) # random password
echo "$IP $USER $NEW_PASS $PORT" >> $NEW_INFO
expect -c "
spawn ssh -p$PORT $USER@$IP
set timeout 2
expect {
\"(yes/no)\" {send \"yes\r\";exp_continue}
\"password:\" {send \"$PASS\r\";exp_continue}
\"$USER@*\" {send \"echo \'$NEW_PASS\' |passwd --stdin $USER\r exit\r\";exp_continue}
}"
done
Generate a new password file:
# cat new_pass.txt
192.168.18.217 root n8wX3mU% 22
192.168.18.218 root c87;ZnnL 22
29, print multiplication formulas
method 1:
# awk 'BEGIN{for(n=0;n++<9;){for(i=0;i++<n;)printf i"x"n"="i*n" ";print ""}}'
Method 2:
for ((i=1;i<=9;i++)); do
for ((j=1;j<=i;j++)); do
result=$(($i*$j))
echo -n "$j*$i=$result "
done
echo
done
30, getopts tool perfect script command-line arguments
getopts is an analytical tool scripting options parameters.
Format: getopts optstring name [arg]
Initial use you should pay attention to these points:
Script positional parameters one by one match optstring in a single letter, if it matches the name assigned to, or assigned name is a question mark;
optstring single letter is an option, if the letters a colon, which indicates that the following option parameters, and the parameter value will be assigned to variables OPTARG;
The first is a optstring colon, showing the shield system error (test.sh: illegal option - h);
It allows the option to put together, such as -ab
The following simple example of writing a print file specified line to guide your thinking:
#!/bin/bash
while getopts :f:n: option; do
case $option in
f)
FILE=$OPTARG
[ ! -f $FILE ] && echo "$FILE File not exist!" && exit
;;
n)
sed -n "${OPTARG}p" $FILE
;;
?)
echo "Usage: $0 -f -n "
echo "-f, --file specified file"
echo "-n, --line-number print specified line"
exit 1
;;
esac
done
