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What is redirection shell?
Redirection allows commands’ file handles to be duplicated, opened, closed, made to refer to different files, and can change the files the command reads from and writes to. Redirection may also be used to modify file handles in the current shell execution environment.
What is I O redirection in shell commands?
Redirection can be defined as changing the way from where commands read input to where commands sends output. You can redirect input and output of a command.
What does redirection mean in the shell script?
Simply put, redirection is the mechanism used to send the output of a command to another place. For instance, if we just cat a file, its output will be printed in the screen, by default:
What does the first character of redirection mean in Bash?
In the following descriptions, if the file descriptor number is omitted, and the first character of the redirection operator is ‘ < ’, the redirection refers to the standard input (file descriptor 0). If the first character of the redirection operator is ‘ > ’, the redirection refers to the standard output (file descriptor 1).
What does 2 > & 1 mean in shell script?
So when you use 2>&1 you are basically saying “Redirect the stderr to the same place we are redirecting the stdout ”. And that’s why we can do something like this to redirect both stdout and stderr to the same place: There are two places programs send output to: Standard output ( stdout) and Standard Error ( stderr );
What are the parts of the snippet redirect to?
The ampersand belongs to the “1”, so the snippet really has three parts: “2”, “>”, “&1”. They mean, respectively, “take the data from output stream 2 (which is standard error)”, “redirect it”, and the redirection target, which is output stream 1. So “&” here allows you to redirect to an existing stream, rather than to a file.