Awk built-in variables and custom variables
In awk, variables are divided into two types: built-in variables and user-defined variables....
How to find empty lines in files in Linux
In Linux, there are three ways to find empty lines in files using grep and awk commands....
How to convert a string to lowercase in Linux?
This section describes how to use sed, awk, TR commands to convert strings to lowercase in Linux...
How to use curl to download 302 redirect files in linux
In linux, use the curl command -L option to download the 302 redirected file....
How to download files using linux command line
In linux, we can use curl command and wget command to download files....
How to fast search for specified content in large files in linux
In linux, to search for specified content in large files, we can use tail -c or head -c commands....
How to find all files containing specific text on Linux?
In linux, to find all files containing a specific text, we can use the grep command, which can search for the specified text in the...
java tutorial: java uppercase first letter
In the following example, two ways to change the first letter to uppercase will be shared. Example 1 * Use ASCII table * The ASCII...
SpringBoot 2.* security turn off login authentication
SpringBoot 2.* security turn off login authentication, use java annotations on the startup method....
Failed to configure a DataSource: ‘url’ attribute is not specified and no embedded datasource could be configured.
Initialize the SpringBoot application and run the following error: Failed to configure a DataSource: ‘url’ attribute is not specified and no embedded datasource could be...
6 methods of executing historical commands in linux bash
!! - repeat the previous command; !t - repeat the previous command headed by t; !Number - repeat the previous command with number ......
Awk classic case – awk analysis of nginx access logs
Awk classic case - awk analysis of nginx access logs.Count top visits and the number of visits in the most recent time....
Nginx combined log format and parameter explanation
Because lnmp does not customize the log format by default, it uses the combined default format: Parameter explanation: $remote_addr, $http_x_forwarded_for record the client IP address....
vim tutorial: vim cursor move
Vim cursor move: 1. up, down, left, and right; 2. to the top of the file; 3. to the end of the line; 4. to...
java tutorial: java enum in switch case
Java enum in switch case : 1. Returns the enum constant of the specified enum type with the specified name. 2. The case label...