15

In Linux if you type

sort < txtfile

is that the same thing as 

cat txtfile | sort
tony_sid
  • 14,957

1 Answers1

19

To your title question: No. Getting stdin from file contents (input redirection) is not the same as piping one program's output to another program's input.

But, as your cat actually just prints a file's contents, the result is effectively the same in that example.

But even just the following produce very different results:

$ cat * | sort
$ sort < *

If there's more than one matching file, the latter will produce

-bash: *: ambiguous redirect

since it's just not as flexible as the former, which will cat all matching files, and pipe them as input into sort.

Daniel Beck
  • 111,893