Shell Scripting

Bash Input Output Redirection

All the commands that we run fundamentally produce two kinds of output;

• the command result - data the program is designed to produce and

• the program status and error message that informs a user of the program execution details

In Linux and other Unix-like systems, there are always three default files named below opened, which are also identified by the shell using file descriptor numbers;

• stdin or 0 -- it is connected to the keyboard, most programs read input form this file

• stdout or 1 -- it is attached to the screen, and all programs send their results to this file and

• stderr or 2 -- programs send status/error messages to this file which is also attached to the screen.

Read more here: https://www.tecmint.com/linux-io-input-output-redirection-operators/#:~:text=One%20of%20the%20most%20important,as%20a%20%E2%80%9Ccommand%20pipeline%E2%80%9D.

and https://tldp.org/LDP/abs/html/io-redirection.html

and https://stackoverflow.com/questions/10508843/what-is-dev-null-21

The simple and best way to redirect all possible output or message from a command (to execute command quietly) is, for example;

$ command >>/dev/null 2>&1

.....

mshaur

This is AUR Helper dash script of Min Soe Han that can update and install AUR packages.
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