linux learning curve

Linux-command learning-df, linux-command-df 1. the df command is used to view the storage of the file system disk of the Linux server. You can use this command to obtain the disk space and the remaining space. 2. du: displays the disk space used by each file and directory. 3. Difference Between du and df Du a

Linux Command learning Summary: last, linux Command summary last Command introduction: This command is used to list information about users currently logged on to the system. Command syntax: show listing of last logged in users Execution permission: Some require special permissions Command path:/usr/bin/last When the last command is executed, it reads the file

[Linux] linux Command learning-netstat Many linux services are related to the network. When the service cannot be called, the startup port is occupied, or the firewall is blocked, you need to query network problems, the netstat command only uses one or two parameters. Common options: -A (all) shows all options. LISTE

, so if the application is frequently allocated more than the allocation threshold of memory, the efficiency is very low, this application can adjust the allocation threshold to make the memory allocation and release in the user state (in the heap) completed. You can use mallopt to adjust the parameters of malloc, m_trim_threshold means that if the heap size is larger than this value, the heap size should be shrunk at the appropriate time, m_mmap_threshold indicates that memory allocation reques

Generally in our keyboard has a PRINTSCREENSYSRQ key, in the Windows system, we press this button can intercept the screen, cut is the whole screen, under Linux I tried, also try to intercept the full screen, is also a screenshot of Linux comes with software, Gnome-screenshot, we can use man to see the specific usage of this command.Here we can see some basic usage of this command.Options-W fetch the curren

1.Linux directory structure is a tree structure, the topmost directory is the directory "/", the other directory by Mount can add it to the directory tree, by lifting the mount to remove them. 2. Absolute path and relative path Absolute path notation: written by the root directory "/", for example:/usr/share/man this directory; Relative path notation: not written by "/", for example, to be transferred from/usr/share/man to/usr/share/doc,

Manage Service CommandsIn RHEL7, the operation of the service command is not the same as CENTOS7 and Rhel6, RHEL6 uses the service, Chkconfig, and so on, while the RHEL7 command is systemctl.650) this.width=650; "src=" Https://s3.51cto.com/wyfs02/M00/96/80/wKiom1kikIzDR0atAACo8AazrOw449.jpg "title=" 1495437210.jpg "alt=" wkiom1kikizdr0ataaco8aazrow449.jpg "/>650) this.width=650; src=" https://s4.51cto.com/ Wyfs02/m00/96/80/wkiom1kiksjby1klaac6cbjwxcw205.jpg "title=" 1495437542.jpg "alt=" Wkiom1k

Manage Service CommandsIn RHEL7, the operation of the service command is not the same as CENTOS7 and Rhel6, RHEL6 uses the service, Chkconfig, and so on, while the RHEL7 command is systemctl.650) this.width=650; "src=" Https://s3.51cto.com/wyfs02/M00/96/80/wKiom1kikIzDR0atAACo8AazrOw449.jpg "title=" 1495437210.jpg "alt=" wkiom1kikizdr0ataaco8aazrow449.jpg "/>650) this.width=650; src=" https://s4.51cto.com/ Wyfs02/m00/96/80/wkiom1kiksjby1klaac6cbjwxcw205.jpg "title=" 1495437542.jpg "alt=" Wkiom1k

notation:1. Specific time: All valid values in the range of valid values for a given point in time;0 5 3 9 *2. Wildcard Time: *, meaning "every ..." means, all valid values at a given point in time;* * * * *3. Discrete time: At a given point in time, use commas to separate;0 8,20 * * 1,3,54. Continuous time: At a given point in time, use a minus sign to separate;0 8 * 1-55. Step time: At a given point in time, use division sign to separate;*/2 * * * **/7 * * * * This method does not implement s

s*When the Chkconfig command is created for this script to create a link in the RC#.D directory, runlevels means that the link is created by default for the beginning of the s*, except that the level is created by default as a link starting with k*; ; K after the closing of the number of priorities for KK represented;#description: A simple function for explaining this script, \ Continuation line breakChkconfig--list server_name: View the startup settings of all standalone daemons by default; In

/root) Gid: (0/root)access:2017-11-11 08:33:41.661983311 +0800modify:2017-11-11 21:01:21.249962087 +0800change:2017-11-11 21:01:21.249962087 +0800State change time. Is the time that the Inode node of the file was last modified, and the file properties are modified by the chmod, Chown command, and the time is updated.[Email protected] ~]# stat oldboy.txtFile: ' Oldboy.txt 'size:0 blocks:0 IO block:4096 Regular empty filedevice:803h/2051d inode:130137 links:1Access: (0644/-rw-r--r--) Uid: (0/root)

: Insert, I can be followed by strings, and these strings will appear on a new line (the current line);P : Print, that is, print out a selected material. Normally p will work with parameter sed-n;s : Replace, work that can be replaced directly, usually in conjunction with regular expressions. Example Description:New action: a commandsed '/^bird/a\test ' file append test to the line beginning with BirdDelete operation: D commandsed '/^$/d ' file # delete blank lines;sed ' 2d ' File # delete the

vendors, such as IBM, Oracle, Intel, HP, MOTO, Google, etc.; complete large database platform including Oracle, DB/2, Sybase, MySQL, PostgreSQL, etc.; Complete graphical user interface, including GNOME, KDE, etc.; There is a perfect development platform, including C + +, Java, Perl, etc., support all kinds of graphical interface API, such as GTK +, QT and so on. Linux is so popular that you want to many of the among IT workers to stand out, you need

Shell scripts are important for Linux system administrators and O M personnel. I recently read the shell script. In order to systematically learn the shell script, I read the third edition of "laruence's Linux basic learning for Private food, chapter 1 describes how to learn shell scripts. You can go to the bird's website: Chapter 13th,

Linux learning notes (10) Text Editor vim, learning notes vim Vim is a powerful full-screen text editor, the most common text editor for Linux/Unix. It is used to create, edit, and display text files. Vim features no menus and only commands. Vim mainly has three working modes: Command mode, insert mode, and edit mode.

preface: I have been in contact with arm-Linux for more than nine months. I have gone through the graduation design and the company's practice design, and have a certain understanding of arm-Linux, it also made me fall in love with arm-Linux and determined to work in Linux later. Beginning in August, I learned how to u

If there is no IDE like windows, how does one compile a project file? For example, how can I run a windows project file under Linux? Next we will first understand two concepts: Compilation and linking. When we get used to programming in windows, after writing the program, we only need to click the button to execute and generate executable files. We will certainly think it is like this: as long as we write the program correctly and then click the butto

LVM Management and Linux system installation1. Preface2.LVM Introduction and terminology3.LVM use4.Linux Partitioning5.Linux Installation ConsiderationsFirst, prefaceThis blog post records the learning experience of Linux, with a focus on the application of Logical Volume Ma

Linux Learning Log: details of the use of virtualization management tools, linux details Virtualization management tools Reason for Virtualization: the power consumption of computer computing is too high, virtualization can greatly reduce the power consumption of Enterprises (Parallel operations in the kernel during virtualization) Key File: cat/proc/cpuinfo | gr

command.sudo configuration file is:/etc/sudoers, to compile sudo configuration file with the command: Visudo, with the General VI command is not compiled.And we edit the Sodoers file also in a certain format, the format of the/etc/sudoers file is: user name (group name) host address = command (absolute path)For example, I want Hellen to have permission to add users, then I use Visudo to edit the configuration file and add the following configuration:Hellen Localhost=/usr/sbin/useradd //There a