Using grep

Hi everyone,

I've read the grep and egrep man pages, and have been unable to figure out the syntax for doing something seemingly simple. I want to be able to grep the piped output of another command (i.e. 'cat MyFile | grep etc, etc) for either:

'foo' or 'bar'

OR

'foo' and 'bar'


The grep man page says the '|' pipe character will function as an 'or' operator, but I can't get the syntax right. And I have no clue how to do the 'and'.

Any ideas?

note: grep, sed, awk and 1000 other *nix progs are all able to open a file
so
cat xx ¦ grep zz
is just stupid, try instead
grep zz xx
sure
cat a b c d e ¦ grep zz
could be reasonable and is not the same as
grep zz a b c d e

I'm actually not using cat, but rather another command. It was just an example of the redirect.

Were you just pointing out the "stupidity" of my example, or do you have any useful suggestions?

bad example

maybe you want
egrep "aaa|bbb|ccc" filea fileb filec
to get all: aaa bbb and ccc from file[abc]

I repeat - not using cat. There are no files involved (and I'd rather not output to file then run grep on the file) - forget all about cat and files. OK? OK. I'm piping the output of one command into grep, like so:

sudo MyAdminCommand -opt1 -arg1 | grep <strings here>

So, think of my original post in that context. I want to be able to run my command, pipe the output into grep, then grep 2 strings, with either 'or' or 'and' [So 'foo' and 'bar' *OR* 'foo' or 'bar'].

Make sense?

lots of ways of doing it really, that's just two.


PS: the syntax will depend on your version of grep, see the grep man page for your system for more details.

Thanks so much - both do exactly what I wanted.

NO, i dont believe it.

my grep ignores the opt -E (i use egrep for this)
imo
sudo MyAdminCommand -opt1 -arg1 | grep -E "foo|bar"
should grep lines containing foo OR bar
and, nuance
sudo MyAdminCommand -opt1 -arg1 | grep "foo" | grep "bar"
(quotes are here useless) line containing foo AND bar