将带有sed的单词插入到文本文件中

Question

I have a text file and I want to insert a word like house before every word that begins with a lower-case letter in a file, using sed. I've tried this but it's not working:

sed "s/(^[a-z]+| [a-z]+)/house (^[a-z]+| [a-z]+)/g" textfile.

Answer 1

I got this line, is it ok for you?

sed -r 's/\b[a-z]\w*\b/HOUSE &/g' file

with example:

kent$ echo "yes No yES NO y_e_s _no"|sed -r 's/\b[a-z]\w*\b/HOUSE &/g'
HOUSE yes No HOUSE yES NO HOUSE y_e_s _no

Answer 2

POSIX friendly version:

sed -e 's/\([^[:alpha:]]\)\([a-z][[:alpha:]]*\)/\1house \2/g' 
    -e 's/^\([a-z]\)/house \1/' input