Thanks. Let me be more specific. My log file "log.txt" is pretty big. About 30 MB. My command line is

Code:

grep -vf exclude log.txt > out

If my "exclude" file is a text file with

Code:

206
304
403
404
405
500

It works fine. Almost instantaneously, the file "out" is created, in which lines with these numbers have been properly removed.

But if my exclude file is

Code:

206
304
403
404
405
500
invite

A blank "out" file is quickly created, but the command line doesn't report that it the command has finished. It just hangs. I am careful, by the way, not to have blank lines in my "exclude" file. top tells me that the grep process is still working hard (100% of CPU!), but the "out" file remains blank. That's what I call "never-never land".

Again, the general rule seems to be that a list of *numbers* in my exclude file works fine, as does one or two alphabetic strings. Three alphabetic strings does not work. Not what's nuts about this is that a number *is* an alphameric string (though not an alphabetic string).