Question

I am issuing a sed replace on a line, trying to extract a particular floating-point value, but all that appears to be matched is the right-side of the decimal

Text Line:

63.544: [GC 63.544: [DefNew: 575K->63K(576K), 0.0017902 secs]63.546: [Tenured: 1416K->1065K(1536K), 0.0492621 secs] 1922K->1065K(2112K), 0.0513331 secs]

If I issue s/^.*([0-9]*.[0-9]*): [Tenured:.*$/1/, my output is:

.546

I m wanting the 63.546 out of the line. Why is the very first [0-9]* not matching?

Answer 1

Also match the ] before the number you want:

s/^.*]([0-9]*.[0-9]*): [Tenured:.*$/1/

Per comment below, here is a more generic approach, matching a non-digit first:

s/^.*[^0-9]([0-9]*.[0-9]*): [Tenured:.*$/1/

Answer 2

My feeling is that your .* at the beginning is acting greedy, so it absorbs everything up to the dot, but I could be wrong.

Don t use sed. I gave up on this. perl is a better choice (I was starting to play with it) but the solution with awk beats me. Go for that, unless you really love sed for some particular reason...

Answer 3

use awk instead sed. why bother creating complex regex?

$ more file
63.544: [GC 63.544: [DefNew: 575K->63K(576K), 0.0017902 secs]63.546: [Tenured: 1416K->1065K(1536K), 0.0492621 secs] 1922K->1065K(2112K), 0.0513331 secs]

$ awk -vRS="]" -F":"  $1+0==$1{print $1}  file
63.544
63.546

Answer 4

As Stefano pointed out, the pattern is performing a greedy match at the beginning of your text input.

If you can use perl, this command works to match your line on standard input:

perl -e  <STDIN> =~ m/^.*?([d]+.[d]+):s+[Ten/ && print "$1
";

友情链接