The cat
command in Linux accepts its input only from standard input (stdin) when used without any file arguments. It reads data from standard input until EOF (End of File) is reached, allowing users to type directly into the terminal or pipe data from other commands. This behavior makes it useful for quickly concatenating and displaying text data.
read (shell builtin command)
grep -ci a
Input device
A Microphone does not output sound. It accepts sound. It is an input device.
The PDA accepts and processes input in various languages.
secret
secret
end of line mark.
0 1 2
dc is a reverse-polish desk calculator which supports unlimited precision arithmetic. It also allows you to define and call macros. Normally dc reads from the standard input; if any command arguments are given to it, they are filenames, and dc reads and executes the contents of the files before reading from standard input. All normal output is to standard output; all error output is to standard error.
a. cat and grep b. tr
The standard console input stream, std::cin.