rs232 commands

into slices for ease of Management/Etc/profild // set the global valid variable, permanently validExport dfsf = dfsf // It takes effect only after cancellationSource/etc/profile // repeat the profile to take effect immediately. It is not recommendedLocal variable :~ /. Bash_profile ,~ /. Bashrc ~ /. Bash_logout is only valid for the current userProfile class:1. Set Environment Variables2. Run some commands to be executed during user logon.Bashrc clas

1.which commandWhen entering a Linux command, the shell actually executes the same name command in which directory, we are not known, can be verified using which.2.whereis commandA command similar to which, Whereis is used to retrieve the file associated with a given command.3.apropos commandUse the apropos command to retrieve commands using the keyword. Apropos will use the keyword provided to retrieve the command summary section of all command book

administrators 9 Files related to Kernel 　　② whatis [command name] or apropros [profile name] is available when viewing brief information about a command(3) Application examples:① help information for the LS command: #man ls② View the Help information for profile services: $man Services (note that you only need to configure the file name, no absolute path is required/etc/services)4.2 get help with Shell built-in commands:(

redirectionStandard input: Code 0, using Standard output: Code 1, using > or >>Standard error Output: Code 2, using 2> or 2>>1>: Output the correct data to the specified file or device in an overriding way1>>: Output the correct data to the specified file or device in an additive way2>: outputting the wrong data to the specified file or device in an overridden manner2>>: The incorrect data is output to the specified file or device in an additive way4. The judgment basis of the command execution

File management commands for Linux commands CP, MV, RMCP, copy command: Copying files or directoriesGrammar:CP [OPTION] ... [-T] SOURCE DESTCP [OPTION] ... SOURCE ... DIRECTORYCP [OPTION] ...-t DIRECTORY SOURCE ... CP SRC DEST:SRC is a file: If Dest does not exist: Creates a new target file and copies the SRC to the target file; if dest exists: If Dest is a file: Use src content to overwrite the dest file;

1. Format description"[email protected] Simon" $"[Email protected] ~" $Both of these methods represent the same. Simon is the specified user, localhost is the computer name, if not set to localhost by default. Simon, ~ refers to the directory where you are currently located.Terminal: Command interpreter, simulation shell2, the user's switchsu[options] [user]such as: Su-rootThe example uses the SU command to change a normal user to the root user and use the option "-" to carry the root environmen

software is difficult to uninstall, but also to prevent the application of other software, you can use this, but a bit risky.Apt-get AutoClean Apt will back up the installed or unloaded software on the hard drive, so if you need space, you can let this command to delete the software you have deletedApt-get Clean This command will also remove the backup of the installed software, but this will not affect the use of the software.Apt-get upgrade--Update all installed packagesApt-get dist-upgrade--

configuration file)dpkg--force-all--purge PackageName Some software is difficult to uninstall, but also to prevent the application of other software, you can use this, but a bit risky.Apt-get AutoClean Apt will back up the installed or unloaded software on the hard drive, so if you need space, you can let this command to delete the software you have deletedApt-get Clean This command will also remove the backup of the installed software, but this will not affect the use of the software.Apt-get u

Shell Special Symbols * Any of any characters ？ Any one character # comment Characters \ de-Semantic characters | Pipe character $ variable prefix,!$ combination, regular inside means end of line ; Multiple commands written to one line, separated by semicolons ~ User home directory, followed by regular expression to indicate match put the command behind the command and throw it backstage. > >> 2> 2>> >

In the previous sections, we have divided Linux commands into several parts based on their functions in the system. However, there are still some commands that are difficult to classify, but learning them is the same In the previous sections, we have divided Linux commands into several parts based on their functions in the system. However, there are still some

In-depth introduction to the use of custom commands in AngularJS and the use of custom commands in angularjs AngularJS custom commands are your own commands, plus native core functions that are run when the compiler compiles the DOM. This may be hard to understand. Now, suppose we want to reuse some specific code on di

provides a function to find corrupted files. Run this command: rpm-Va. Linux will list all corrupted files for you. You can fix the issue through the Linux installation CD. 8. in Linux, there are many files, which we will inevitably encounter when using. in Windows, we can use the "Start/search" menu to quickly determine which folder a file belongs, in Linux, the following command line can help us quickly determine which software package a file belongs: Rpm-qf 9. after each software package

We can modify the/etc/bash. bashrc file (other users are in their respective directories) so that we can automatically load our custom commands when logging on to shell. In the process of using linux, it is inevitable that a long string of commands will be bored if they are frequently typed ...... When calling some executable files, you have to write down a long string of parameters ...... We can modify the

Common commands for MongoDB and Common commands for mongodbCommon commands for MongoDB Databases Show dbs # show database use test # select/create database db. dropDatabase () # Delete the current database db # display the current database db. test_col.insert ({x: 1}) # insert (create set) var_insert = {a: 1, B: 3} db. test_col.insert (var_insert) # insert db as

Sort notes-common Git commands, notes-common git commands In Windows, configure SSH to connect to GitHub/GitLab ==> when you need it, follow the search criteria Baidu. Echo "content"> file name ==> string output. 1. Global Configuration: Git config -- global user. name "user name" Git config -- global user. email "email address" Note: Removing -- global is not a global configuration. It will create. git/co

Common mysql commands and common mysql system commands Recently, some mysql commands were often used during my internship, so I made some preparations: Solve the character garbled problem: display Chinese characters rather than garbled characters: set names utf8; Change New password: update user set PASSWORD = password ('new password') where user = 'username '

Common vro configuration commands and simple configuration tutorials, common vro configuration commands View arp table in arp-a on the computer Arp-s IPadd MAC in computer for arp binding Arp-d in computer clears arp cache Router arp-a view arp table Vroarp arp IPadd MAC for arp binding Vroclear clear arp-cache clear arp cache Ip route network mask IPadd configure Static Routing Show running-config under t

Linux common command-permission management command chmodu/g/o +/-/r/w/x change permission user/user group/other user increase/decrease/Grant read/write/execute r4w2x1rwxr-xr -- 754752: rwxr-x-w-question: if other users have 7 permissions on the file... permission management commands for common Linux Commands Chmod u/g/o +/-/= r/w/x change permission user/user group/other user increase/decrease/Grant re

Common Git commands and git commands Since work, the source code management tool has used SVN, TFS, Git, and finally exclusive Git This blog summarizes the Git commands used in my work. The main directories are as follows:1. obtain remote code Generally, every company that uses Git as the source code management tool will have its own Git server. When we obtain th

Simple JSP exercises-JSP commands, jsp-jsp commands I. page commands: When defining the global attribute value of a JSP page, you can use the page command to place it in the header of the page. For example: Note: The contentType attribute in the page command cannot be specified twice on the same page. The page directive has many attributes. The attribute enclos