linux practice test

package, download the installationRemove Uninstall, the configuration file is not deletedAutoremove will remove unused packagesClean Delete the buffer storage inside the hard driveUpdate download updates package list informationUpgrade Upgrade SystemSystem Core configuration file:ETC/PASSWD and Etc/shadow passwd is the account information, and Shadow is the password. Said originally in passwd can see encrypted secret law, but because passwd file is often stolen, crack root secret method, now pa

Linux C programming practice (5 )?? Driver Design 1. introduction the device driver is the interface between the operating system kernel and the Machine hardware. it shields the hardware details for applications. Generally, the Linux device driver must complete the following functions: (1) initialize the device. (2) provide various... C programming practices in

script file named "$" variable, the first parameter is $ ~ ~ So, as long as we use in script, we can easily release some command function immediately! In addition to the variables of these numbers, we have a few more special variables that can be used within a script to call these parameters Oh!$#: On behalf of the following parameters "number", the above table as an example shown here as "4";[Email protected]: for "$" "" $ "" $ "" $ "" $4 "meaning, each variable is independent (enclosed in dou

Today, the best way to learn about Linux is to use the common Linux technology-Linux technology and application information. For more information, see the following. Do you want to quickly master Linux skills? Think, okay. I'll tell you a way. Don't worry, you don't have to pay for me. Let's talk about the results I ha

Article Title: Practices and discussions on Linux Embedded Systems. Linux is a technology channel of the IT lab in China. Includes basic categories such as desktop applications, Linux system management, kernel research, embedded systems, and open source. 　　 1. Practical Purpose 　　 Transplant the KERNEL of KERNEL 2.6 to a mature embedded hardware platform;

byte at a time, so it takes a lot of time. Therefore, this solution is not very practical. LVM Method In Linux, Logical Volume ManagerLVM) can also be used to create snapshots, which saves a lot of time than the previous disk file method. This method means that your VM uses the LVM logical volume as the storage backend and compares it with the Virtual Disk File. Because of this logical volume, you need to create a snapshot next. This snapshot is a ty

Job target:Linux OPS Practice-September 5, 2015 Course Assignment (practice) ScheduleWorking Environment: CentOS 6.7/7 x86_64First, homework (exercise) content:1. Summarize the detailed usage method of the task plan (at, crontab) on Linux system;2, every Monday to Saturday 3:20 A.M., run the CP command to archive the/etc/directory, storage location is/BACKUPS/ETC

signal Volume API synthesis PracticePractice 1: Encapsulate the PV primitive Union mysemun{int val; Value for setval//struct semid_ds *buf; Buffer for Ipc_stat, ipc_set//unsigned short *array; Array for GETALL, setall//struct seminfo *__buf; Buffer for Ipc_info (linux-specific)//};//encapsulates V operation int sem_v (int semid) {struct Sembuf buf = {0,+1,0}; Return Semop (semid,buf,1);} Package P operation int sem_p (int semid) {struct Sem

Linux OPS Practice case-December 20, 2015-December 31 (first time)1. Create a 10G file system, type ext4, requires the boot can be automatically mounted to a separate data /data directory; Create a 10G partition [Email protected] ~]# FDISK/DEV/SDAWarning:dos-compatible mode is deprecated. It ' s strongly recommended toSwitch off the mode (command ' C ') and change display units toSectors (Command ' u ').Co

indicates the permissions of others. Each number can be 1 (Execution permission), 2 (write permission), 4 (read permission), 0 (none), or the sum of these values. For example, to create a readable, writable, and executable user, but the group has no permissions, other users can read and execute files, and set the user ID. Then, we should use 1 (Set User ID), 0 (do not set group ID), 7 (1 + 2 + 4, read, write, and execute) 0 (no permission), 5 (1 + 4, read and execute), that is, 10705: open ("

Article Title: Remote Control Technology and practice for Linux servers. Linux is a technology channel of the IT lab in China. Includes basic categories such as desktop applications, Linux system management, kernel research, embedded systems, and open source. Concepts and origins of

According to the online article collation.Load balancer software LVs (Linux Virtual Server) concept paperLVS is based on the Linux operating system to establish a virtual server, to achieve the load balance between service nodes. It is implemented based on the Linux kernel. The 2.6.X kernel is integrated with the LVS module by default.The implementation of common

-image:none; border-bottom:0px; padding-top:0px; padding-left:0px; border-left:0px; padding-right:0px "border=" 0 "alt=" wpsc47b.tmp "src=" http://s3.51cto.com/wyfs02/M02/72/9E/ Wkiom1xpa43azlglaag-xihlve4751.jpg "" 561 "height=" 271 "/> 19, create the directory/test/data, let a group of ordinary users have write permission to it, and all the files created by the group of directories belong to the group, in addition, each user can only delete their ow

to create Useradd"[Email protected] ~]# VI 24p2.sh[Email protected] ~]#[Email protected] ~]# Ll/tmp/testdir1Total 0[Email protected] ~]# chmod +x 24p24p1.sh 24p2.sh[Email protected] ~]# chmod +x 24p2.sh[Email protected] ~]#[Email protected] ~]#./24p2.sh[Email protected] ~]#[Email protected] ~]# Ll/tmp/testdir1Total 0-rw-r--r--. 1 root root 0 Nov 11:29 newdir[Email protected] ~]#3) Write a script that requires:Select a user randomly from the same UID and GID in/etc/passwd to determine whether th

, So I suggest that you can use the timer (Linux Contrab) every few minutes to synchronize the latest memcahced data to the database, even if the server power off, but also lost only a few minutes of data, it is acceptable, of course, the server for no reason the probability of power loss is very small.I would like to compare this with the above example you should see what memcached can solve. Mainly used to alleviate the database pressure.(2) Now a l

Tags: technology so linux image pressure condition save Server ACThe previous article mainly on how to use JMeter under the Windows system for stress testing, but found some problems, when the QPS reached a certain peak, due to the Windows machine itself bottlenecks caused by the network card can be compressed, in addition to the formal environment, Development wants to test for IP, press only one machine,

enter on the Linux control Terminal:./mydaemon, Haha, why didn't you react? In fact, is not unresponsive, is you this Mydaemon program has been running in the background!Enter "Ps-ef" and see!See that Mydaemon! The PID of this run is 11618, the parent process is the PID is who? Linux init!4, Exit Daemon Program: The daemon program does not interact with console input and output, so it is unrealistic to con

Linux DHCP service practice-Linux Enterprise Application-Linux server application information. The following is a detailed description. We know dhcp is a dynamic IP Address Allocation service pull! In a network, if there are not many computers, we usually manually assign IP addresses and other network settings to each

boot:Chkconfig--list MySQLView MySQL listens on the listening port (default is 3306 ):Netstat -lt | grep MySQL" MySQL user name, remote login Settings "How to install and start the above MySQL , MySQL after the initial installation, you also need to set up user name, password, and remote login and so on. MySQL by default, only Root user, and the password is blank, this machine is not allowed to log on to other machines. If you want to set a password to root and allow it to telnet, you need to d

"); Elseprintf ("read from msg queue%d bytes\n", Reval); Msg_stat (MsgId, msg_ginfo); Msg_sinfo.msg_perm.uid=8; Msg_sinfo.msg_perm.gid=8; Msg_sinfo.msg_qbytes=16388; Reval= Msgctl (MsgId, Ipc_set, msg_sinfo); if(Reval = =-1) {printf ("msg Set Info error\n"); return; } msg_stat (MsgId, msg_ginfo); Reval=Msgctl (MsgId, Ipc_rmid, NULL); if(Reval = =-1) {printf ("unlink msg Queue error\n"); return; }}voidMsg_stat (intMsgIdstructMsqid_ds Msg_info) { intReval; Sleep (1); Reval= Msgctl (MsgId,