Oliver Fromme <o...@lurza.secnetix.de> writes: > John Levine <jo...@iecc.com> wrote: > > > > % egrep 'word1|word2|word3|...|wordn' filename.txt > > > > > Thanks for the replies. This suggestion won't do the job as the list of > > > words is very long, maybe 50-60. This is why I asked how to place them > all > > > in a file. One reply dealt with using a file with egrep. I'll try that. > > > > Gee, 50 words, that's about a 300 character pattern, that's not a problem > > for any shell or version of grep I know. > > > > But reading the words from a file is equivalent and as you note most > > likely easier to do. > > The question is what is more efficient. This might be > important if that kind of grep command is run very often > by a script, or if it's run on very large files. > > My guess is that one large regular expression is more > efficient than many small ones. But I haven't done real > benchmarks to prove this.
BTW, not using regular expressions is even more efficient, e.g. $ fgrep -f /usr/share/dict/words /etc/group When using egrep(1) it takes considerably more time and memory. _______________________________________________ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "freebsd-questions-unsubscr...@freebsd.org"