The manual says:
Redirecting Standard Output and Standard Error
This construct allows both the standard output (file descriptor 1) and
the standard error output (file descriptor 2) to be redirected to the
file whose name is the expansion of word.
There are two formats for redirecting standard output and standard
error:
&>word
and
>&word
The &>word part is correct:
imadev:~$ foo &>1
imadev:~$ cat 1
stdout
stderr
imadev:~$ rm 1
However, the >&word is not correct:
imadev:~$ foo() { echo stdout; echo stderr >&2; }
imadev:~$ rm 1
imadev:~$ foo >&1
stdout
stderr
imadev:~$ ls -l 1
1 not found
This is because >&filename and >&n conflict with each other. If the word
is not a valid file descriptor number then the >&word part works as
advertised:
imadev:~$ foo >&xyzzy
imadev:~$ ls -l xyzzy
-rw-r--r-- 1 wooledg pgmr 14 Oct 12 15:58 xyzzy
imadev:~$ cat xyzzy
stdout
stderr
Even using a space is not sufficient to force a valid file descriptor number
to be treated as a filename:
imadev:~$ foo >& 1
stdout
stderr
imadev:~$ ls -l 1
1 not found
Personally I wish all the csh compatibility features would go away forever,
but I appreciate that it's too late to remove them at this point. But
I think the manual should be updated to indicate that the >&word form
just plain fails for certain words, even with a space.
