grep: match all characters up to (not including) first blank space

Question

I have a text file that has the following format:

characters(that I want to keep) (space) characters(that I want to remove)

So for example:

Answer 1

I use egrep a lot to help "colorize" log lines, so I'm always looking for a new twist on regex. For me, the above works better by adding a \W like this:

$ egrep --color '^\S*\W|bag' /tmp/barf -o
foo
bag
hello
bag
keepthis
(etc.)

Problem is, my log files almost always are time-stamped, so I added a line to the example file:

2013-06-11 date stamped line

and then it doesn't work so well. So I reverted to my previous regex:

egrep --color '^\w*\b|bag' /tmp/barf

but the non-date-stamped lines revealed problems with that. It is hard to see this without colorization...