So I've been trying to use grep to extract some stuff from a Mercurial log and trying to avoid using awk just to see if I can get by without it here, and failing because neither grep nor egrep support full modern regex.So this happens with grep:$   hg log <filename> | grep changesetchangeset:   3651:d23495ab1168changeset:   2974:6aa71cb2c575changeset:   2756:9dd7fb635678changeset:   2532:d3ced9af4d6cchangeset:   2459:9d5f5553b851changeset:   1835:4558836beed1changeset:   1628:517d0239e830changeset:   1486:114bce51254dchangeset:   1378:2b968e7fbd19changeset:   1374:4e7772e48d00This is what I want in terms of output results. But to get better regex support, I tried doing this with ack, aaaand....nothing. What am I missing? Checked a bunch of examples and can see no difference in what I'm doing here.$  hg log <filename> | ack changeset$ There is no output.Maybe I am misunderstanding this tool? egrep did not have enough support either. I just want to use \s :(
Why can't I pipe to ack?
grep;ack