dbase iv commands

properties:To view file properties:[Email protected] ~]# ls-l File.log-rw-r--r--. 1 root root 12:11 file.logThis is also mentioned in the previous notes, but there is no mention of the authority. Permissions are divided into three groups, from left to right are the main permissions, belong to group permissions, other people permissions. R stands for readable, W is writable, X is executable for the file, and is accessible (CD) for the directory. After the permission. is related to SELinux. The i

simply enters the command man and the name of the command shell will list a complete description.Standard usage:Name of the man commandTo query the description page of the LS command, enter the command: Man lsTo flip through the manual page, you can use the page UP and PAGE DOWN keys, or use the spacebar to turn back one page and use B to flip forward. To exit the manual page, enter the command Q. To search for keywords in the manuals page, enter a command/and keyword or phrase to search for, a

, unused and mount points and other information. See the rest of the spaceSyntax: DF [-hkam] [Mount Point]-H (human-readable) displays KB,MB,GB in an easy-to-read manner based on disk space and usage-K displays information for each partition in kilobytes, by default-m displays information in megabytes-a show all partitions including partitions of size 0duFunction: Used to view the size of a file or directory (disk usage space)Syntax: du [-ABHS] [file name directory]-a displays the size of the ch

usage -B (-K,-M) Units in bytes (in KB,MB units) -T Show total Totals Netstat Options Show Network status -lnp Which ports are currently enabled on the system -an Used to display network connection status Ping [Options] Target Test the connection status of the target to the local machine 　 -C User-specified test how many times, if not add, will be e

files)(soft links are more like shortcuts in Windows)[[emailprotected] boke]# ll -itotal 12912130 -rw-r--r--. 2 root root 2 Apr 23 12:28 fu918011 drwxr-xr-x. 2 root root 4096 Apr 23 12:30 mulu925186 lrwxrwxrwx. 1 root root 5 Apr 23 12:47 mulu2 -> mulu/912130 -rw-r--r--. 2 root root Find command Ls-r directory (recursively find all files/directories in the directory) Whereis (7 system, finding the specified command) which command (alias variable, type whic

directories and printed the names of the programs. The grep command can use regular expressions, and the functionality is very powerful, and here we don't focus on the introduction.The head and tail commands are also often used to compose pipeline commands. Head can view the previous part of a file or text. Tail View the end of a file or text. Both can receive the-n option, which indicates the number of ro

every second, but this is actually different from top. You will find that the output of the Top/htop command is refreshed more frequently than the PS command above. This is because the top output is a sorted value that combines the CPU usage values and memory usage values.But the PS command above is a simpler sort of behavior that gets one column at a time (like math at school), so it doesn't update as fast as top. Reference:http://linux.cn/thread/12046/1/1/This article is from the "Bread" blo

each group. To take effect. $InputRunFileMonitor # When submitting logs to a different server, specify the server Ip:port here separately, #如都提交在同一服务器只需在rsyslog. conf specify one time to #local5.*@ @192.168.1.251:514Restart Rsyslog service in effect#service Rsyslog RestartAppendix: Linux Naming short format reference%%aliteral%%alocale ' sabbreviated weekdayname (E.g.,sun)%alocale ' Sfullweekday name (e.g.,sunday)%blocale ' sabbreviatedmonth name (E.g.,jan)%blocale ' sfullmonthname (e.g., janua

(1) Get help information: ManMan command get command Help info 1.gzMan profile file name get profile Help (no path required) 5.gzExample: Man lsMans ServicesView Profile man 5 passwd(2) Get command Short message: WhatisExample: Whatis ls(3) Get profile brief information: AproposExample: Apropos services(4) Get command options information:--helpExample: LS--help(5) Get help information: info (same man)Example: Info ls(6) Get help with Shell built-in commands:Example: Help UmaskLinux Notes (

The full path to use the PWD command to view the current working directory in Linux. Simply put, you will have a current working directory every time you operate in a terminal. 1. pwd [ Options] 2. Command function:View the full path to the current working directory3. Common parameters:Normally without any parametersIf the directory is a link :Format:pwd-p shows the actual path, not thelinkpath. Other parameters: --help online Help.--version Displays version information.4. Common ex

-nand 11 use, tell read command to accept single word specifier exitCode 2-25[Email protected]:/data# cat Demo5 #!/bin/bashread-n1-p "Do you want to continue [y/n]" Answercase $answer in y|y) E Cho echo "fine,continue on ...";; N|n) echo echo "Ok,goodbye" exit;; Esacecho "This is the end of the script" [email protected]:/data#./demo5 does you want to continue [y/n]yfine,continue on]. . This is the end of the script　　Hidden mode read, the-S optio

recursivelyCommand: Mkdir-p test2/test22Example 3: Create a directory with permissions of 777:Command: Mkdir-m 777 Test3Output:[[email protected] test]# mkdir-m 777 Test3[[email protected] test]# lldrwxr-xr-x 2 root root 4096 10-25 17:42 test1drwxr -xr-x 3 root root 4096 10-25 17:44 test2drwxrwxrwx 2 root root 4096 10-25 17:46 Test3[[email protected] test]#Description: The TEST3 permission is rwxrwxrwxExample 4: Creating a new directory displays informationCommand: Mkdir-v test4Output:[Email pr

query time, resulting in slower efficiency. The workaround is to use the index for sorting. If the order required for the query is the same as the sort used by the index, because the indexes are sorted, and therefore the results are returned in sequential read by index, the using Filesort does not appear at this time.As for the difference between using index and using index condition, I refer to an article on StackOverflowHttp://stackoverflow.com/questions/1687548/mysql-explain-using-index-vs-u

the query, and Usingfilesort will appear. Sorting naturally increases query time, resulting in slower efficiency. The workaround is to use the index for sorting. If the order required for the query is the same as the sort used by the index, because the indexes are sorted, and therefore the results are returned in sequential read by index, the using Filesort does not appear at this time. As for the difference between using index and using index condition, I refer to an article on StackOverflow H

Commands for shutting down and viewing system information1.shutdown: Normal shutdown(Note: You must be a root user, or you will need to switch to the root user with the SU command)Eg: shutdown in less than 5 minutes: shutdown-t 5Restart after shutdown: shutdown-rCancel shutdown operation: shutdown-cOther parameters can refer to the following table:2.reboot: Shutdown command. (Fastest shutdown, no memory or buffer data saved to memory)Parameter options

and more in-depth discussion. Well, today we'll introduce this, next time we continue to learn the common command five: rmdir command.Jerry EducationSource:http://www.cnblogs.com/jerehedu/ Copyright Notice: The copyright of this article belongs to cigarettes DeskJerry EducationSection Technology Co., Ltd. and blog Park are shared, welcome reprint, but without the consent of the author must retain this paragraph, and in the article page obvious location to the original link, otherwise reserves t

The Linux operating system is a multi-user operating system that allows multiple users to log on to the system and use resources at the same time. Each user's files, processes, tasks, and work environment are differentiated according to the account, making every user work undisturbed1. Files to save user information:/etc/passwd2. Save the user password file:/etc/shadow3. Save the user group's files:/etc/group4. Save the user group password file:/etc/gshadow5. User profile:/etc/default/useradd6.l

Rights Management Command: chmod only the file owner and root user have this permission.Mode 1:chmod u g o +-= R W x file or directoryWay 2:chmod r-4 w-2 x-1-r Recursive Change permissionsR W X Three permissions are different for files and directories.Files: r--can view the file contents directory: r--can list content in a directoryFiles: w--can modify the file contents directory: w--can create and delete files in the directoryFile: x--can execute file directory: w--can enter directoryChown: Cha

Root indicates the currently logged on userLocalHost host name~ Current location (~ =/root)# Super User$ normal UserCommand1.pwd Show Current Location2.ls querying content in a directory-a displays all files, including hidden files (the. Start with hidden files)- L display details-LH ll=ls-l-D View Directory properties-H humanized Display file size-I displays the ID number of the Inode file-rw-r--.File type (-File d directory | Soft link (shortcut))rw-r--RU owner G Holder O OtherR Read W write X

character must appear as the first word\> front character must appear as a suffix\d Digital Match\d non-digit matching\s white space character matching\s non-whitespace character matching\{m,n\} \ is used to escape, prevents {} from being parsed by bash , matches the preceding character at least M times, up to N times , \{1,\} represents at least once, up to no limit. Operator Precedence\ Escape Character[] square brackets Expression() grouping*,+,? ,{m},{m,},{m,n} QualifierNormal characters f