A wildcard wildcard is a class of keyboard characters. Wildcards are often used in place of one or more real characters when looking for a folder, when you don't know the true character, or if you don't want to type the full name. * Instead of 0 or more characters. Instead of one character. [] matches any one of the characters within the brackets. Example of a wildcard: LS *.confls/home/*.shls H*.confls test?. CLS [abc]* shell command redirection < standard input, changes the path of the command to receive input from the default keyboard to the specified file. > Standard output, the execution result of the command
Outputto the specified file. >> standard output, the result of the command execution
append output to specified file。 2> standard Error,
empties the contents of the specified file and saves the standard error information to the file。 2>> standard Error,
Append standard error information to the specified file。 &>
save all standard output and standard error contents to the specified file. | Reads the output from one command and writes it to the input of another command, also known as a pipe operator.
Linux Command basics: Shell operators and keyboard wildcard characters
