I am having a hard time understanding the difference between the order of 1>&2 and >. For example, I have file and file and don't have fie. Then diff fie file2 gives me error and I try redirecting the error message to stdout as follows:
$ diff fie file2 > out.log 2>&1
$ cat out.log
diff: fie: No such file or directory
However, if I reverse the order as
$ diff fie file2 2>&1 > out2.log
diff: fie: No such file or directory
$ cat out2.log
$
the output is different. Why is this? and if the STDERR and STDERR are merged by 2>&1, will the file descriptor 2 be empty? and can anyone point to a reference about >& and <& ? Thank you.
2>&1basically means "take whatever it is that fd 1 points to right now, and make fd 2 also point to the same place"