basic coding commands

MongoDB Basic Commands After the MongoDB is successfully started, you can then open a command line window to enter MONGO to perform some operations on the database. Enter help to see basic operations commands: Show DBS: Displaying a list of databasesShow Collections: Displays the collection in the current database (si

1. Practice cmd -- Help, help cmd, man cmd, info cmd. Compare the differences and find the command usage method. A: After my tests, taking ls as an example, ls -- help is helpful in Chinese, and display is completed and released at one time. Help ls result Bash: Help: no help topic matching "ls". Try "Help help", or "man-K ls" or "info ls" The returned results of man ls and info ls are basically the same. 2. What is the meaning of-L and-A of the LS command? Use the LS command to list files and

As a common Internet user, sudden network faults have a headache. They not only affect our use, but also cause unnecessary losses, therefore, simply understanding the basic network test commands is also a good thing for us, saving time and improving work efficiency. Today, I would like to list some of the most common network failure test commands for your referen

. And..LS-A does not display:6, how to get help information of the commandBuilt-in commands: Help commands, for example: Help historyExternal command: 1, command--help example: Ifconfig--help2, man ifconfig actual check is (/usr/share/man)Garbled, Input: Export lang=en, and then man ifconfig there is no garbledThe manual is divided into chapters, generally 1-9 chapters, the paragraph of the manual:Name: Nam

-pecl-apcu php-devel php-mbstring php-mcrypt Php-mysqlnd php-phpunit-phpunit php-pecl-xdebug php-pecl-xhprof php-pdo php-pear php-fpm php-cli php-xml Php-bcmath Php-process PHP-GD Php-commonRestart ApacheService httpd Restart2. Write Phpinfo () test① methodUsing Vim to write: vim/var/www/html/index.phpWrite the Phpinfo () in it;② methodCommand: Php-v#=============================================linux directory Structure ========================================#root directory (/): Places all the

need to enter a colon: into the bottom line mode, in the bottom row mode, enter the Wq to write the content and exit, that is, save, enter the q! on behalf of the forced exit does not save. Summarize:Vim Editor is a powerful component of Linux, is the VI editor of the enhanced version of the Vim editor commands and shortcuts there are many, but here is not one, we do not need to study the very thorough, using VIM to edit the way the file will be use

quotation marks, even if the \ and carriage returns within the quotation marks are no exception, but single quotes cannot appear in the string. If the quotation marks are entered without pairing, the shell gives a continuation prompt that asks the user to match the quotation marks. For example:itcast$ echo ' $SHELL '$SHELLitcast $ Echo ' abc\ (carriage return) > DE ' (press ENTER again to end the command)ABCDE Double quotesThe content enclosed in double quotes is treated as a single string. It

Examples of four basic commands in AngularJS this article describes four basic commands in AngularJS. We will share this with you for your reference. The details are as follows: Of the four basic commands, Note that the usage of

Linux Security Basics: shell and some basic commands, linuxshell 1. What is shell?Shell is the interface between the user and the Linux operating system.There are multiple shells in Linux, where Bash is used by default. 2. shell Classification(1) bashBash shell is a free version of Bourne shell. It is the earliest Unix shell, including many additional features. Bash has an editable command line that allows

Linux companies commonly used basic commands must be knownThe basic commands are divided into six parts, which are commonly used in some companies to summarize the following commands:Installation and Logon commands:Login, shutdown, halt, reboot, install, mount, Umount, Chsh, exit, last;File processing commands:File, mk

;Cs:context switch, process switching rate;Memory: RAM UsageSWPD: Total amount of swap memory used;Free: The total amount of idle physical memory;Buffer: The total amount of memory used for buffer;Cache: The total amount of memory used for the cache;Swap: Swap partition rateSI: Data rate for data entry into swap (KB/S)So: Data rate from swap (KB/S)These are the basic command methods commonly used in process management.I have limited level, if there is

Basic commands under the Linux systemLinux System basic commands: to distinguish caseuname display version information (same as Win2K ver)dir Displays the current directory file, Ls-al display includes hidden files (dir with Win2K)pwd Query the directory location where you are currently locatedCD CD. Go back to the pre

: Executable Script6.4.1 Ls-lDisplays the details of the files in the directory6.4.2 Ls-aShow files or directories that contain the beginning of the.The files in Linux that begin with. are hidden files6.4.3 Ls-ldDisplay the properties of the directory itself6.4.4 Ls-hShow file size in a friendly way6.4.5 LS-LHSShow files in order from large to small6.4.6 Ls-iDisplaying the inode for a file6.5 CatDedicated to viewing text file contentCat/etc/redhat-release viewing the System release version6.5.1

Linux Study Notes 2-linux basic commands and Study Notes 2-linux First blog: linux Study Notes 1-ubuntu installation and basic settings, has introduced how to install the linux operating system and some basic settings and modifications. This blog introduces some basic Conso

1. Command prompt user@ubuntu-hansee:~/test$ global variable PS1 ps2 echo $PS 1: \[\e]0;\[emailprotected]\h: \ w\a\]${debian_chroot:+ ($debian _chroot)}\[emailprotected]\h:\w\$ echo $PS 2: > A few basic hints meaning: \u: User \h: local hostname \w: Current working directory name \T:24 hour time \t:12 hour system Modify the command prompt for the current terminal Direct assignment: ps1= "[\t][\u]$" Modified effect--[09:46:09][user]$

include multiple servers for multiple users to access. In addition, the peer-to feature allows some systems to play the dual role of the client and server. HBase is a distributed, column-oriented, open-source database that comes from the Google paper "Bigtable: A distributed storage system of structured data" written by Fay Chang. The Yonghong Data mart is a software that is based on proprietary technology developed for the storage and processing of information. Yonghong Data Mart's Distributed

Mysql -- mysql basic operation command: selectDATE_FORMAT (runTime, % Y-% c-% d) fromhdfsPicLogtwherepathlike % liveEpg3 % andcount30andDATE_FORMAT (runTime, % Y-% c-% d) 2013-10-30; change the primary key to primary key auto-increment: altertablehdfsPicLogm Mysql -- mysql basic operation command: select DATE_FORMAT (runTime, '% Y-% c-% D ') from hdfsPicLog t where path like '% liveEpg/3/%' and count 30 and

Basic concepts and commands for CentOS users and groupsUser Group:Group type:Administrator GroupCommon User GroupSystem GroupLogon Group Group ID: GroupID and GroupID (Normal user 1-65536)Administrator group: 0 Common User Group: System group: CentOS 5, 6: 1-499 CentOS 7: 1-999 Logon group: CentOS 5, 6: 500 + CentOS 7: 1000 + Name resolution: groupname Resolution Library:/etc/group Group type: user-center

Basic configurations of Cisco routers and Cisco router configuration commands En -- enter the privileged mode config t -- enter the global configuration mode wr (OR) -- save the configuration (otherwise, the configuration fails before the power-off) 1. Set the password for entering the vro Console In global configuration mode, enter line console 0 --- enter the '0' Interface password 123 -- set the password

file from the 512-byte block position represented by the number variable.-C number starts reading the specified file from the byte position represented by the number variable.-F assumes that the input file is a regular file or assumes that the file parameter specifies a FIFO (first in and out),Then the tail command will not terminate after the last specified unit of the input file has been copied, but continueRead and copy additional units from the input file (when these units are available).If