[Help-bash] $<space><tab> completes to files rather than commands

[Michal Pesa]

Hello.

Please take a look at the following scenarios where "$" is the beginning 
of the prompt:

1) $<tab> # complete -E will be used

2) $p<tab> # commands beginning with "p" will be completed

3) $<space>p<tab> # commands beginning with "p" will be completed again

4) $<space><tab> # all files in the current dir (for some reason) will 
be completed

Why doesn't 4) complete to all possible commands instead of all files 
since it's the first word on the line? Is the completion of the first 
word configurable at all (not counting complete -E)? Let's say I wanted 
$p<tab> to complete only to a subset of commands I choose.


Thank you for your time.