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What is shell command why it is used?
A shell is a computer program that presents a command line interface which allows you to control your computer using commands entered with a keyboard instead of controlling graphical user interfaces (GUIs) with a mouse/keyboard combination. Your computer can do the same thing a thousand times with no mistakes.
Which command sends the output of a command to a file?
To redirect the output of a command to a file, type the command, specify the > or the >> operator, and then provide the path to a file you want to the output redirected to. For example, the ls command lists the files and folders in the current directory.
Which is the output of a Bash command?
STDOUT – the standard output of the shell. By default, this is the screen. Most bash commands output data STDOUT to the console, which causes it to appear in the console. The data can be redirected to a file by attaching it to its contents using the command >>.
Where does standard error go in the shell?
Standard error (“stderr”) is like standard output and standard input, but it’s the place where error messages go. To see some stderr output, try catting a file that doesn’t exist: Hey, that output looks just like stdout! But wait a moment.
How are input and output handled in Linux?
Sometimes something needs to be shown on the screen, and something needs to be written to a file, so you need to understand how input and output are handled in Linux, which means that you need to learn how to send the results of the scripts where you need to. Let’s start by talking about standard file descriptors.
Why do I need to store my Bash output in variables?
Sorry, there is a loong answer, but as bash is a shell, where the main goal is to run other unix commands and react to resut code and/or output, ( commands are often piped filter, etc… ). Storing command output in variables is something basic and fundamental.