Tag:Special symbols

  • Special Symbols and Regular Expressions in Linux


    Chapter 1 Special Symbols of Linux 1.1 wildcard * {} 1.1.1 meaning Easy to find file wildcards are used to find file names. 1.1.2  * Find the file ending with. sh by using the find command, and replace the file name with *. find /oldboy -type f -name “*.sh” -mtime +7 -size +100k -size -10M […]

  • Explanation of Common Special Symbols in Scala


    => (Anonymous function) => An anonymous function, in Spark, is also an object that can be assigned to a variable. Spark’s anonymous function definition format: (Parametric List) => {Function Body} So, the function of => is to create an anonymous function instance. For example: (x: Int) => x + 1, is equivalent to the following […]

  • Docker Container Related Commands


    Doker run pulls the image directly from the docker hub. If it’s available locally, it uses it directly. There are two parameters – D – it, – D is a separate mode, – it is an interactive mode, and – D is more. Docker pull pulls directly from the hub, images list all local mirrors, […]

  • Solve the problem of sorting numbers and special symbols in Oracle strings


    Problem Description: A residential area needs to be sorted according to the residential area, building, unit number and room number, but when sorted according to address description, because the string contains numbers, the results are as follows. After building 1, it should be building 2, but the query result is building 10. Trying to solve […]

  • Introduction of Special Symbols in Perl


    $_   In the old place known as perl, when your program does not tell which parameter or variable to use, Perl automatically uses the value in $, such as for(1..10){ print ; } Here print does not specify a parameter, so it uses $, so what’s in $? The value of $changes every time you […]