Linux operation and maintenance basic problem (III.)

AWD sed Problem
add a blank line after each line
sed G file
 
insert a blank line after the line that matches the style "regex"
sed '/regex/g ' file
 
Count rows (simulate "wc-1")
wc-l File
 
Insert 5 Spaces at the beginning of each line (to move the full text 5 spaces to the right)
sed ' s/^//' file
 
Replace "foo" with "bar" and replace only if the string "Baz" does not appear in the row
sed '/baz/! s/foo/bar/g ' File
 
concatenate each of the two lines into one line (similar to "paste")
sed ' $! n;s/\n//' File
 
displays rows containing "AAA ", "BBB", "CCC" (Fixed order)
sed '/aaa.*bbb.*ccc/!d ' file
 
keep only one row in the repeating row, and the others are deleted
sed ' $! N /^\ (. *\) \n\1$/! P D '
 
Delete Multiples of 8 rows
sed ' n;n;n;n;n;n;n;d; '
 
change "Haiwao" in line 50th of the file test to "Haiwai"
sed-ie ' 50s/haiwao/haiwai/g ' test
 
use the SED command to replace all the carriage returns in the test.txt with spaces.
sed-i ' s/\r//' Test.txt

There are files File1
query File1 The line number of the empty line Grep-n "^#" file1| awk-f ":" ' {print '} '
Print File1 's 2nd to 5th line Sed-n ' 2,5p ' file1
query File1 The line that ends in Hai grep abc$ file1

look for files with the/usr/local/apache/logs directory last modified longer than 30 days and delete.
find/usr/local/apache/logs-type f-mtime +30-exec rm-f {} \;

add a route to 192.168.3.0/24 with a gateway of 192.168.1.254.
Route add-net 192.168.3.0/24 GW 192.168.1.254

within November, every 2 hours from 6 o'clock in the morning to 12 o '/usr/bin/httpd.sh how to implement
0 6-12/2 */usr/bin/httpd.sh

How to forward a local 80 port request to port 8080, the current host IP is 192.168.2.1
iptables-t nat-a prerouting-d 192.168.16.1-p tcp--dport 80-j DNAT--to 192.168.16.1:8080
iptables-t nat-a prerouting-i eth0-d 192.168.16.1-p tcp-m tcp--dport 80-j REDIRECT--to-ports 8080

allow the machine to connect to the external 80 port (this function with the external server for the)
iptables-a output-p tcp–dport 80-j ACCEPT
Open 3306 ports on this machine
iptables-a input-p tcp--dport 3306-j ACCEPT
prohibit external ping of the server
iptables-a input-p icmp-j DROP

use a command to view the ports on which the system is currently being monitored by the service being started
netstat-antl |grep "LISTEN"

please use the Linux system command to count the number of connections to the establish state.
Netstat-an |grep |grep established |wc-l

 

Linux operation and maintenance basic problem (III.)