On Wed, Apr 17, 2013 at 8:17 PM, Bob Proulx <b...@proulx.com> wrote: > The only regexp replacement in the right hand side is "$&". The > perlre docs say: > > man perlre > > $& returns the entire matched string. (At one point $0 did > also, but now it returns the name of the program.) > > This comes from use in 'sed'. In sed the docs say: > > man sed > > s/regexp/replacement/ > Attempt to match regexp against the pattern space. If > successful, replace that portion matched with replacement. The > replacement may contain the special character & to refer to > that portion of the pattern space which matched, and the > special escapes \1 through \9 to refer to the corresponding > matching sub-expressions in the regexp. > > And can be used like this: > > $ echo fore | sed 's/fore/be&/' > before > > All of the \e [ (escape bracket) patterns are terminal escape sequence > colors as the others mentioned. Personally I find using them like > that annoying since they are non-portable. It would be better to use > 'tput' to generate those from the terminfo data instead. > >> tail -f file.log | perl -pe 's/keyword/\e[1;31;43m$&\e[0m/g' > > Instead of that I would be inclined to use grep's --color option. > Same thing but easier to type and remember. > > tail -f file.log | grep --color keyword >
Thank you Bob. I like how you get to the source (sed) and to the problem (use grep). Very informative, and I'll be reading this post a few times over. -- Dotan Cohen http://gibberish.co.il http://what-is-what.com -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/cakdxfkn9z8xovqgfwpdsawkyj4gxsowzuaufqebdf2p9vlo...@mail.gmail.com
