lh3/bioawk — Issue #5: header does not respect FS flag in BEGIN
Author: brentp
Created: 2012-02-06 16:03:15+00:00
State: open

this will demonstrate the problem:

Given his text file

```Shell
echo $'a space\tb\n1\t2\n1\t2' > t.txt
```

and this code:

```
./awk 'BEGIN{FS="\t"}{ print $b }' t.txt
```

I expect:

I expect the following to print

```
b
2
2
```

but it instead gives nothing because it splits the headers on space sets them as are `a`, `space`,`b`
even though the separator is '\t'. This is because the headers are parsed before the BEGIN block
sets FS.