Tag:Special symbols

  • Some special symbols in shell scripts


    The special symbols commonly used in the shell are listed as follows: # ; ;; . , / \\ ‘string’| ! $ ${} $? $$ $* \”string\”* ** ? : ^ $# [email protected] `command`{} [] [[]] () (()) || && {xx,yy,zz,…}~ ~+ ~- & \\<…\\> + – %= == != #Comments This is almost a […]

  • Introduction to special symbols in Perl


    $_   In the old place commonly known as Perl, Perl will be used automatically when your program is not told which parameter or variable to use$_ Values in, such as ? 1 2 3 for(1..10){   print ; } Here print does not specify parameters, so it uses $_, That$_ What’s inside? Each cycle$_ The value […]

  • MySQL FAQs


    reset password Close MySQL servicesudo /etc/init.d/mysql stopRun in MySQL safe mode and skip permission verificationsudo mysqld_safe –user=mysql –skip-grant-tables –skip-networking &Log in to MySQL as root with an empty passwordsudo mysql -u root mysqlUpdate passwordupdate user set Password = PASSWORD(‘root’) where User =’root’;update mysql.user set authentication_string=password(‘root’) where user=’root’ ;Refresh permissionsFLUSH PRIVILEGES;sign outquitThe password is too simple. […]

  • [share] IOS development – limit input of special characters


    -(void)viewDidLoad { self.specialStringArray = [@[] mutableCopy]; NSString * string = @”~,¥,#,&,*,<,>,《,》,(,),[,],{,},【,】,^,@,/,£,¤,,|,§,¨,「,」,『,』,¢,¬, ̄,(,),——,+,|,$,_,€,¥”; self.specialStringArray = [string componentsSeparatedByString:@”,”]; } //Call this method where needed -(void)submit { NSString * intriduction = self.textField.text; for (NSInteger i = 0; i < self.specialStringArray.count; i ++) { //Determine whether the string contains special symbols if ([intriduction rangeOfString:self.specialStringArray[i]].location != NSNotFound) { [myutil showtiptext: @ […]

  • JS skills – drawing special characters in canvas


    The simplest and most practical way to draw special symbols in canvas is to usecharacter, withfillTextTo draw in the same way. Of course, if there are special requirements for the style of special symbols, the use of pictures is also a good choice. Here we only introduce the character drawing method. Scheme 1: use special […]

  • HTML (004) – what is the difference between HTML and XHTML? Which one do you think should be used and why


    answer: XHTML should be usedBecause XHTML is XML, which rewrites the specification of HTML and is more strict than HTML 1. All tags in XHTML must have a corresponding end tag; 2. The names of all elements and attributes of XHTML tags must be lowercase; 3. All XML tags must be nested reasonably; 4. All […]

  • Linux learning notes task planning crontab


    A series of articles: Linux learning notes — File packaging and decompression Linux learning notes task planning crontab Task plan crontab Crontab command is commonly used in UNIX and UNIX like operating systems (Linux belongs to UNIX like operating system), which is used to set instructions to be executed periodically. If we need to clean […]

  • MySQL Foundation: version 8.0 installation


    blog:https://www.cnblogs.com/Rohn/ catalog Install MySQL version 8.0 Add source install Start and set auto start Change the root password Install MySQL version 8.0 System environment: CentOS Linux release 8.1.1911 (Core) Add source rpm -Uvh https://repo.mysql.com//mysql80-community-release-el8-1.noarch.rpm dnf clean all install dnf install mysql mysql-server mysql-devel Start and set auto start systemctl enable mysqld systemctl start mysqld Change […]

  • Filtering file name symbols using golang


    Filtering file name symbols using golang Recently, the customer service department has encountered a problem: it’s connected with a third party to mail files. Every time you send a file, you need to upload it. It happens that the name of the uploaded file doesn’t support special symbols such as “% &”. It’s too troublesome […]

  • How to extract origin (scheme + domain + port) information from a URL string?


    preface Recently, I met a requirement: UsingpostMessageTo achieve cross domain communication.There is one thing to pay attention to: when the receiver receives a message, it needs to be aware of the senderoriginCheck, if not the target sender, then do nothing, this is recommended for security reasons. The data I have in my hand are: information […]

  • How to type the inverted question mark of computer? How to input the inverted question mark of special symbol


    How to input inverted question mark? How to play inverted question mark?The inverted question mark comes from Spanish. The inverted question mark represents a question in the following sentence or clause. Let’s take a look with XiaobianHow did you type the inverted question mark。 1. Click where you want to insert the inverted question mark. […]

  • Summary of bat special symbols


    ^Escape characterUsed before special symbolsFor example:Echo non ^ & batch processingIf you do not add ^ the batch will be executed as a command |Pass through characterTransmission, of courseFor example:echo 0123456 | find “123” Pass 0123456 to find lookup 123 ||ConnectorWhen the previous command is not executed successfully, the subsequent command is executedFor example:Echo 0123456 […]