Shulou(Shulou.com)06/02 Report--

Find a file

Find /-name filename.text / / follow the filename.txt file under / directory by name

Find.-name ".xml" / / Recursively find all .xml files

Find.-name ".xml" | xargs grep "Hello World" / / Recursively find all xml files containing hello World

Grep-H 'spring' * .xml / / find some xml files that contain spring

Find. /-size 0 | xargs rm-f & / / Delete a file with zero file size

Ls-l | grep 'jar' / / find all jar files in the current directory

Grep 'test' d* / / displays all lines that contain test in files that begin with d.

Grep 'test' aa bb cc / / displays the lines that match test in the aa,bb,cc file.

Grep'[a murz] / {5 /}'aa / / displays all lines that contain at least five consecutive lowercase characters for each string.

Check whether a program is running

Ps-ef | grep tomcat / / View all processes related to tomcat

View files, including hidden files

Ls-al

Current working directory

Pwd

Copy a file

Cp sourceFolder targetFolder

Scp sourecFile romoteUserName@remoteIp:remoteAddr / / remote copy

Create a directory

Mkdir newfolder

Delete directory

Rmdir deleteEmptyFolder / / Delete an empty directory rm-rf deleteFile recursively delete everything in the directory

Move Fil

Mv / temp/movefile / targetFolder

Rename

Mv oldNameFile newNameFile

Switch users

Su username

Modify file permissions

Permissions for chmod 777 file.java / / file.java-rwxrwxrwx,r for read, w for write, x for executable

Compressed file

Tar-czf test.tar.gz / test1 / test2 / / compress test1 test2

List the compressed files

Tar-tzf test.tar.gz

Extract the file

Tar-xvzf test.tar.gz

View the first 10 lines of the file

Head-n 10 example.txt

View the last 10 lines of the file

Tail-n 10 example.txt

View log type files

Tail-f exmaple.log / / this command automatically displays the new content, and the screen displays only 10 lines of content (configurable).

. / startup.sh & & tail-f.. / logs/catalina.out / / restart the tomcat output log

Execute commands using the Super Admin identity

Sudo rm a.txt / / use the administrator to delete the file

View port occupancy

Netstat-tln | grep 8080 / / View the usage of port 8080

Check which program the port belongs to

Lsof-I: 8080

View the process

Ps aux | grep java / / View java process

Ps aux / / View all processes

List the contents of the directory in a tree view

Tree a

File download

Wget http://file.tgz

/ / install the wget command under mac

Curl http://file.tgz

Network detection

Ping www.taobao.com

Remote login

Ssh userName@ip

Print information

Echo $JAVA_HOME / / print the value of the java home environment variable

Java common commands

Java javacjps, jstat, jmap, jstack

Other commands

Svn git maven

Grep command function

Grep command is a powerful text search tool in Linux system. It can use regular expressions to search text and print matching lines. The full name of grep is Global Regular Expression Print, which represents the global regular expression version, and its permission is for all users.

Ps Command reference Article

Ps is the abbreviation of Process Status. The ps command is used to list the processes currently running on the system. The ps command lists the current snapshots of those processes, that is, those at the time of the execution of the ps command. If you want to display process information dynamically, you can use the top command.

In order to monitor and control the process, we must first understand the current process, that is, we need to look at the current process, and the ps command is the most basic and powerful process view command. Use this command to determine which processes are running and running status, whether the process ends, whether the process is dead, which processes are taking up too much resources, and so on. In short, most of the information can be obtained by executing the command.

Ps provides us with an one-time view of the process, and the results it provides are not dynamic and continuous; if you want to monitor the time of the process, you should use the top tool.

The kill command is used to kill the process.

1. Command format:

Ps [parameters]

2. Command function:

Used to display the status of the current process

3. Command parameters:

A show all processes

-a displays all programs under the same terminal

-A shows all processes

C display the real name of the process

-N reverse selection

-e equals "- A"

E display environment variables

F shows the relationship between programs

-H shows the tree structure

R displays the progress of the current terminal

T displays all the programs of the current terminal

U specify all processes of the user

-au displays more detailed information

-aux displays all itineraries that include other users

-C lists the status of the specified command

-number of rows displayed per page of lines

-number of characters displayed per page of width

-help displays help information

-version display version display

Example

Ps-A / / displays all process information

Ps-u root / / displays the specified user information

Ps-ef / / displays all process information, along with the command line

Ps-ef | grep ssh / / ps and grep are commonly used in combination to find a specific process

Ps-l / / list the PID and related information that currently belong to you this time

Ps aux / / lists all the programs currently in memory

Ps-axjf / / lists the program display similar to the program tree

Ps aux | egrep'(cron | syslog)'/ / find out the PID number related to cron and syslog

Chmod

Linux chmod command is one of the most commonly used commands in daily operation and maintenance, and it is more important for file management, such as setting specific permissions when setting the web directory to ensure server security.

Tip: after writing a shell script, we generally need to set permissions to the script: chmod aquix shell.sh

Give chmod-R 777 file to programs and directories directly. This kind of highest permission will cause great security risks to server security. Generally, it is not recommended to set up web directory permissions on online servers. Chown can be configured to set the permissions of web directories. For example, the user permissions for uploading pictures are set to web, and the same settings are also set for directories in web that need to be operated by programs: chown-R apache:apache web. For other read-only files or directories, keep root permissions, which can increase server security.

Linux command: chmod

Permissions: all users

Usage: chmod [- cfvR] [- help] [- version] mode file. Note: the file call authority of Linux/Unix is divided into three levels: file owner [owner], group, and other users. Using chmod, you can control how files are called by others.

Chmod-related command: chown,umask, parameter: mode: permission setting string, format as follows:

[ugoa...] [[+-=] [rwxX]...] [,...] Where u represents the owner of the file [user], g

Indicates that the owner of the file belongs to the group (group), o indicates other users [other], and an indicates that all three are [all]. (commonly used)

Means to increase permissions, (commonly used)

Indicates the revocation of permissions, (commonly used)

= indicates the only set permission.

R indicates readable permission, w indicates writable permission, x indicates executable permission, and X indicates only if the file is a subdirectory or if the file has been set to executable.

-c: show the change action only if the file permission has indeed been changed.-f: do not display an error message if the file permission cannot be changed-v:

Display details of permission changes

-R: make the same permission changes for all files and subdirectories in the current directory (commonly used)

Example: modify all readable permissions for all to the file:

Chmod ugo+r linuxyw.com

Or

Chmod Aguilr linuxyw.com

Modify all executable permissions for all to the file:

Chmod axix linuxyw.com

Modify all executable permissions for the primary user to the file:

Chmod upright x linuxyw.com

Set the files in the linuxyw directory to everyone's executable permissions:

Chmod-R axix linuxyw/

Set all files in the linuxyw directory to 755 permissions:

Chmod-R 755 linuxyw/

Revoke writeable permissions for all files in the linux directory:

Chmod-R a Murw linuxyw/

Example

Execute ll

Return

Drwxr-xr-x 2 root root 4096 Apr 29 14:50 linuxyw

-rw-r-r- 1 root root 36 Apr 27 23:40 linuxyw.com

-rw-r-r- 1 root root 0 Apr 29 14:46 www.linuxyw.com

The result of ll returns seven columns, which indicate the following:

First column [file properties]

Column 2 [number of files]

Column 3 [owner]

Column 4 [owner Group]

The fifth column [size]

Column 6 [date of filing]

Column 7 [file name]

We set the permissions of the file is that this is the file properties in the first column.

There are ten fields in the file attributes section, such as drwxr-xr-x

Let's divide the 10 columns into four blocks: [d] [rwx] [rmurx] [rMuix]

The first block: the first column, which is used to indicate the type of the file, is like the following value:

(1) [d] is a directory, and what I have here is d, which means a directory.

(2) [-] is a document.

(3) [l] is expressed as a linked file (link file)

(4) [b] is represented as an interface device available for storage in the device file.

(5) [c] is expressed as a serial port device in the device file, such as keyboard and mouse.

The second block: columns 2 to 4, indicating the permissions of the file owner.

The third block: columns 5 to 7, indicating the permissions of the owner in the same group.

Block 4: columns 8 to 10, indicating the permissions of non-owner groups.

These permissions are indicated by three parameters [rwx] and correspond to different locations. Each block consists of three columns with a value for each column. [r] stands for readable, [w] for writable, and [x] for executable.

For example: if the owner only has read-only access, then columns 2 to 4 are [r -], the right to read and write is [rw-], and the right to read, write and execute is [rwx].

The command format for using numeric weighting is as follows:

Chmod abc filename

The abc represents three numbers and corresponds to a different subordinate group. That is:

The number a corresponds to bits 2 to 4, indicating the owner's permissions.

The number b corresponds to bits 5 to 7, indicating the permissions of users in the same group.

The number c corresponds to bits 8 to 10, indicating the permissions of other groups.

Rwx corresponds to 4, 2, 2, 1. Then read-only permissions are 4 for [rw- -], 6 for read and write for [rwx], and 7 for write plus execution for [rwx]. Read-only plus execution is denoted by 5 (4: 1) [rmurx].

Example:

Chmod 755 file1

Chmod 777 file1 chmod a=rwx file

Chmod 771 file chmod ug=rwx,o=x file

Chown

Chown changes the owner of the specified file to the specified user or group, the user can be the user name or the user ID; group can be the group name or the group ID; file is a list of files to change permissions separated by spaces, and wildcards are supported. System administrators often use the chown command to give users permission to use a file after copying it to another user's directory.

1. Command format:

Chown [options]... [owner] [: [group]] file...

2. Command function:

Change the owner and group of files through chown. You can use the user name and user identification number settings when changing the owner or group to which the file belongs. Ordinary users cannot change their files to other owners. Its operation authority is generally an administrator.

Examples

Example 1: change the owner and group

Command: chown mail:mail log2012.log

Example 2: change file owners and groups

Command: chown root: log2012.log

Example 4: change the owner and group of all files under the specified directory and its subdirectories

Command: chown-R-v root:mail test6

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.