Basic Linux Symbols

Some common symbols in the Linux environment

; Delimiter for multiple commands

/root directory or path delimiter

> redirect, Data Flow in the direction of the arrow, the original file content will be discarded

>> add content to the end of the original file

.. Top level Directory

. Current directory

~ User Home Directory

| The pipeline passes the output of the previous command to the next command to continue processing.

{} with echo print sequence echo {1..10}

The PATH environment variable, all the paths contained within the environment variable, can be directly knocked out to execute.

Global effective/etc/profile Normal user ~/.bash_profile or ~/.BASHRC

Redirect: Used frequently in Linux, which means redirecting data streams.

> or 1> standard output redirection: Redirect data flowing to standard output to a file in the back, the original content of the file is discarded

>> or 1>> standard output append redirect: Repositions data flowing to the standard output to the end of the file at the back, adding data at its tail. The original contents of the file will not be discarded

< or <0 standard input redirection: redirect source traffic from standard input to other files, overwriting the original data

<< or <<0 standard input append redirect: Redirect source traffic from standard input to other files without overwriting the original data, appended

2> standard error Redirection: Redirect data flowing to standard error to a file in the back, the original content of the file is discarded

2>> standard error Append redirect: Relocate the data flowing to the standard error to the end of the file file at the back and add the data at its tail. The original contents of the file will not be discarded

Standard input, standard output, standard error is the three files that the Linux kernel has opened for each process, with file descriptors of 0,1,2

Basic Linux Symbols