I want to redirect this awk output to the file handle but no luck.

Code:

```
open INPUT,"awk -F: '{print $1}'/etc/passwd| xargs -n 1 passwd -s | grep user";
while (my $input=<INPUT>)

{
...rest of the code
}

```

Error:

```
Use of uninitialized value in concatenation (.) or string at ./test line 12.
readline() on closed filehandle INPUT at ./test line 13.

```