alienware 13 linux

)# || .----------Day (1-31)# ||| .-------Month (1-12)# |||| .----Week (0-6) (Sunday =0 or 7)# |||| |# * * * * * * user-name command to be executedCron is also a service, so you need to start the service to be effective: service Crond start; Service Crond StatusTask Schedule Exercises:Clear/var/log/slow.log This file every 1:20 A.M.Execute "/bin/sh/usr/local/sbin/backup.sh" every Sunday 3 o'clock14th # 4:10 per month to execute "/bin/sh/usr/local/sbin/backup_month.sh"Perform "Ntpdate time.windows

://s5.51cto.com/wyfs02/M01/82/91/wKiom1da0BDC6DYcAAB8ofMduuI580.png "title=" Picture 26.png "alt=" Wkiom1da0bdc6dycaab8ofmduui580.png "/>Clock Source: Pclk_psysBus Control logic unit: generation of IIC Communication timing (Setup I2ccon , I2cstat )Shift Register: the data 1bit shift to SDA lineComparator + address Register: Compares the address to the address register address as it will be received when used from the device.I2ccon : Clock ConfigurationI2cstat : operation mode and condition bit s

edit operationThe continuous u command undoes the previous n edit operations#u: Undo Recent # edits directlyUndo the most recent undo action: Ctrl+r12. Repeat the previous edit operationDot character.13, the visualization mode is used to delete the copy and paste operationsV: Select by characterV: Select by rectangle14, find (support regular expression, in the last row mode)/pattern from yourselves to tail? PATTERN from current to headerN: Find from

/yum.repo[Server]name=rhel7.1baseurl=ftp://172.25.0.254/pub/rhel7.1Gpgcheck=0: WqYum Clean All # #清空yum缓存识别新配置Yum commandYuminstallsoftwarename # #安装Repolist # #列出设定yum源信息Removesoftwarename # #卸载Listsoftwarename # #查看软件源中是否有次软件List all # #列出所有软件名称List Installd # #列出已经安装的软件名称List Available # #列出可以用yum安装的软件名称Clean All # #清空yum缓存Searchsoftwareinfo # #根据软件信息搜索软件名字Whatprovidesfilename # #在yum源中查找包含filename文件的软件包Update # #更新软件History # #查看系统软件改变历史Reinstallsoftwarename # #重新安装Infosoftwarename # #查看软件信息

number of files in two files and their total number of rows;8. Write a script(1) Prompt the user to enter a string;(2) Judgment:If the input is quit, exit the script;Otherwise, the string content of its input is displayed;9, write a script, print 2^n table; n equals the value entered by a user; (Sorry, I'm naughty)10, write a script, write a few functions: function 1, to achieve the sum of two numeric values, function 2, take a given two numeric value of greatest common divisor, function 3, ta

Anonymous pipelines can only communicate between processes that have kinship, so what if you want to communicate between strangers without having relatives?Don't panic, Linux as the world's * powerful operating system, of course, provides this mechanism, that is named pipe ...The so-called named pipe, that is the name of the pipeline, but also known as FIFO, talking about FIFO, then do a single-chip development of the students must be not unfamiliar.I

.png-wh _50 "/># # #3. cut###Cut # #截取字符cut-d Delimiter # #指定分隔符Cut-f 1,7 # #显示制定的列Cut-c 1-4 # #显示指定的字符# # #4. sort### # #排序Cp/etc/passwd/mntvim/mnt/passwdSort-n # #纯数字排序-U # #去冗余|UNIQ-C # #去除冗余并统计冗余次数-T # #指定分隔符-K # #制定列# # #5. uniq###Sort file |uniq-c # #去除冗余并统计冗余次数-D # #显示冗余行-U displays unique rows# # #6. sed###Sed ' s/original character/replacement character/g ' fileSed-e ' policy '-e ' strategy 2 ' fileSed-i File # #把转换后的内容输入到指定文件Sed ' 3,5s/meta character/replacement character/g ' # #3-5 li

TCP connection:Control connection: TCP 21 port, sending FTP command informationData connection: TCP 20 port, uploading dataData connection modeActive Mode: server 2 Port-Active connection-"client"Passive mode: Server XX Port-Passive connection-ClientXX port range must be pre-qualifiedTransfer modeText mode: ASCLL mode, text sequence transferBinary mode: Binary mode, binary sequence transferFTP User typeAnonymous User: FTP or AnonymousLocal User: Linux