Linux Common Utility Commands

viewing disks

Df-h

View the size of the file folder under the current directory.

Du-sh *

viewing system CPUs

Top then press "1": you can see how many nuclear CPUs there are

Free-m See how much memory there is.

View 2743 thread-occupied handles

/usr/sbin/lsof-p 2743

/usr/sbin/lsof-p 2743 |grep del |wc-l: 2743 process-related modules contain the number of Del characters.

WC is statistic

-L is how many lines-C is containing the number of characters

View the number of threads in the system that occupy the handle. and the corresponding thread number

/usr/sbin/lsof-n|awk ' {print $} ' |sort|uniq-c |sort-nr|more

View detailed information for a thread number.

Ps-aef|grep 24204

File store path without release handle

Log on Cd/proc with root privileges

LS displays a directory of all current process number names

Find the corresponding process to enter

CD FD

Ls

The flash is a file marked as deleted.

Cause there is no release handle: The thread opens the file. Another thread deletes the file. will appear to the problem. Kill the Dour process to free all handles.

grep error stdout.log |more-c view error log

grep ERROR stdout.log.*-C

Get the port that a thread occupies

netstat-anp| grep 13755

Query whether a port is occupied

netstat-a | grep 14444

You can log in root with Isysearch users. (specially added function)

sudo su-root

Login to MySQL

Mysql-u username-p

VI does not support the input of Chinese.

WORKAROUND: In ESC state: Set Encoding=utf-8

But can only be used in the current window.

To be effective, users need to reuse the household directory

Vim. VIMRC

Type set Encoding=utf-8

View Host Uname-a

Reboot reboot the machine.

Look at the pressure tool thread Ps-ef|grep JM

View the number of files under a folder, including those in subfolders.

Ls-lr|grep "^-" |wc-l

View the number of folders under a folder, including those in subfolders.

Ls-lr|grep "^d" |wc-l

The-i option of grep indicates that case is ignored

VI Jump to the last line]

VI jumps to the first line [[

VI jumps to the beginning of $

VI jumps to the end of the line ^

Df-m is shown in M

Df-h is shown in G

Folder Links

Ln-s/home/support/nosql_data Nosql_data #nosql_data指向其他目录

Delete

RM Nosql_data

Show line numbers when viewing files

NL a.txt

Modify folder Owner

Chown–r Username/dir dozen dir to username users

View Disk IO

Vmstat 1 100

Ll-t sorted by latest time

Pass the variables in SSH to the script for addition to the calculation. can have decimals.

a=2

B=4

echo $a, $b |awk-f "," ' {Print $1/$2} '

Pass the result of the script to the variable in SSH (included with ' number)

l10= ' grep ' $TODAY ' $FILE _path_stroe_get|wc-l '

Show host all restrictions

Ulimit-a