I'm trying to get this script to basically read input from a file on a command line, match the user id in the file using grep and output these lines with line numbers starting from 1)...n in a new file.

so far my script looks like this

```
#!/bin/bash
linenum=1
grep $USER $1 |
while [ read LINE ]
do
echo $linenum ")" $LINE >> usrout
$linenum+=1
done

```

when i run it `./username file`
i get

```
line 4: [: read: unary operator expected

```

could anyone explain the problem to me?

thanks