Input Redirection

Just like as the output of a command can be redirected to a file, so can the input of a command be redirected from a file that is the input for a command can be taken from a file alter of taking from the standard input (keyboard).

Syntax

command < filename

In the given case, here less than (<) sign is used to redirect the input of command from the filename. Let consider the following:

# sort < mydata

Whenever the sort command opens the standard input and starts to read, it will read from the file mydata and not from the keyboard.