shell script question,standard input,output,error

cola · 04-14-2010, 01:58 PM

Code:

echo "Redirect this STDOUT to STDERR" 1>&2
cat $1 2>&1
grep -r hda6 * . 1>&2 stderr.txt
grep -r hda6 * . 2>&1 stderr.txt
grep -r hda6 * . &> stderr_and_stdout.txt

Can someone explain these commands?

pixellany · 04-14-2010, 04:09 PM

What happens when you run them?

Not on a Linux box ATM---so I can't try...

pixellany · 04-14-2010, 04:47 PM

A few quick experiments says that those commands don't make sense.

e.g. you can redirect to a file, or to another standard FD, but not both.

So--add to my earlier question: What are the commands **supposed to** do?

cola · 04-14-2010, 11:11 PM

Which is the correct syntax?

Code:

cat b.c 2>&1 file1.txt

or

Code:

cat b.c>file1 2>&1

PMP · 04-15-2010, 01:11 AM

The second one is correct!!