understand Korn shell numeric statements

Question

Have lot of questions in ksh as i struggle to understand the code. here is one which i couldnt find the answer

function prn_msg
{
   print "command usage: "
   print "   $COMMAND -i<id> -d<date>"
    exit $BADOPTIONS
} 1>&2

I understood that it prints the text to a stderr output and exits the shell execution with the return code in BADOPTIONS. but don't understand what does the 1>&2 do

See http://stackoverflow.com/questions/818255/in-the-shell-what-does-21-mean for explanation of Unix file handles 1 and 2. — Bernard Assaf, Oct 06 '15 at 17:56
always wonder why they made it so difficult to understand :) — xGen, Oct 07 '15 at 04:58

score 1 · Answer 1 · answered Oct 08 '15 at 08:22

In the comment OP asks for a simple answer. The link given by @Bernard tells more, two simple answers are:

Output to the screen is divided in (1) normal output and (2) error output. 1>&2 is a method to reroute normal output to the error output.

and

It is a way to make the output of that function being written to stderr, which can be filtered later.

Note: I never use 1>&2 but use 2>&1 a lot. That way you can redirect both to a file or /dev/null.

understand Korn shell numeric statements

1 Answers1