Common UNIX Operation and maintenance commands of shell

1、 Find all in the directory to .zip The last file is moved to the specified directory .

find . -name “*.zip” -exec mv {} ./backup/ ;

2、 Find the current directory 30 Days ago, it was greater than 100M Of log File and delete .

find . -name “*.log” –mtime +30 –typef –size +100M | xargs rm –rf {};

3、 Batch decompress the current directory to .zip At the end of all the files to the specified directory .

for i in find . –name "*.zip" –type f
do
unzip –d $i /data/www/
done

annotation ：for i in （command）;do … done by for A common format for loops , among i As a variable , You can specify that .

4、 Write a script to find the last creation time is 3 Days ago, , Suffix is *.log And delete .

find . -mtime +3 -name “*.log” | xargs rm -rf {};

5、 Write a script to make a directory larger than 100k Move your file to /tmp Next

find . -size +100k -exec mv {} /tmp;

6、 How to determine whether a directory exists , If it doesn't exist, create a new one , Print information if it exists .

if [ ! –d /data/backup/ ];then
mkdir –p /data/backup/
else
echo “ directory already exists ”
fi
-d Representative directory

7、 Replace the directory in the file

sed ‘s:/usr/local:/tmp:g’ test.txt

perhaps

sed -i ‘s//usr/local//tmp/g’ test.txt

8、sed Common commands

How to get rid of the beginning . character :

sed -i ‘s/^.//g’ test.txt

Add a... At the beginning of the line a character :

sed ‘s/^/a/g’ test.txt

Add a... At the end of the line a character :

sed ‘s/$/a/’ tets.txt

Add a... After a specific line z character ：

sed ‘/rumen/az’ test.txt

Add a c character :

sed ‘/rumenz/ic’ test.txt

9、sed Another usage is to find the current line , Then modify the parameters after the line

sed -i ‘/SELINUX/s/enforcing/disabled/’ /etc/selinux/config

sed Colon mode , It means that /tmp Change to /tmp/abc/.

sed -i ‘s:/tmp:/tmp/abc/:g’ test.txt

10、 Statistics Nginx Access log Top of the list of visits 20 Of ip Address

cat access.log |awk ‘{print $1}’|sort|uniq -c |sort -nr |head -20

annotation ：sort Sort 、uniq（ Check and delete the repeated rows and columns in the text file ）

11、 Modify the text to ab Replace the ending with cd：

sed -e ‘s/ab$/cd/g’ b.txt

12、 Network packet capture ：tcpdump

# Grab 56.7 adopt 80 Packets requested by the port .

tcpdump -nn host 192.168.56.7 and port 80

# exclude 0.22 80 port

tcpdump -nn host 192.168.56.7 or ! host 192.168.0.22 and port 80

13、 Statistics bash_history Most commonly used 20 Bar command

history | awk ‘{print $2}’ | sort | uniq -c | sort -k1,1nr | head -10

14、 Configure firewall scripts , Only remote hosts are allowed to access local 80 port

iptables -F
iptables -X
iptables -A INPUT -p tcp --dport 80 -j accept
iptables -A INPUT -p tcp -j REJECT
perhaps
iptables -A INPUT -m state --state NEW-m tcp -p tcp --dport 80 -j ACCEPT