grep question

[sunny8107]

Hello,
Is there a way using /bin/grep that I print lines that contains BOTH String1 and String2?

Thanks.

[HROAdmin26]

grep <STRING1> filename | grep <STRING2>

[sunny8107]

Thanks. I was dabbling with Regular expressions ... I guess my next question is how do I match a line which contains EITHER String1 or String2

Thanks again.

[HROAdmin26]

C'mon man...

Just run two commands...

grep <STRING2> filename

grep <STRING1> filename

[lomcevak]

Or you can use one command:

grep -e 'string1' -e 'string2' filename

[HROAdmin26]

Or you can use one command:

grep -e 'string1' -e 'string2' filename

Absolutely true, but the "no brainer" way to me would be to run two commands - no thought required.

Maybe there is some weird "one command" requirement. But if so, it would be helpful if that was included in the OP's question.

Does this count?

grep <STRING1> filename; grep <STRING2> filename

[lomcevak]

Does this count?

grep <STRING1> filename; grep <STRING2> filename

Well it does save you from having to press <Enter> twice.

The OP said he/she was dabbling in regex. So, you also can do it with extended regex as follows:

grep -E '(string1|string2)' filename

[SagaciousKJB]

grep <STRING1> filename | grep <STRING2>

This will pipe only lines which contain string1 to grep, which will try to find lines that containe string2, but will not find any because the first grep command only found string1.

sagacious@amd:~$ cat ./testfile
string1
string2

sagacious@amd:~$ grep string1 ./testfile | grep string2
sagacious@amd:~$

Your other example specifies the filename, which doesn't account for using STDIN, but isn't really what the OP wanted.

The OP wanted grep to match lines that contained string1 and string2 in the same execution. I suppose that's obvious now, but I guess I felt it necessary to correct your first example.

I personally use the regex pattern that lomcevak posted.

[HROAdmin26]

This will pipe only lines which contain string1 to grep, which will try to find lines that containe string2, but will not find any because the first grep command only found string1.

sagacious@amd:~$ cat ./testfile
string1
string2

sagacious@amd:~$ grep string1 ./testfile | grep string2
sagacious@amd:~$

Your other example specifies the filename, which doesn't account for using STDIN, but isn't really what the OP wanted.

The OP wanted grep to match lines that contained string1 and string2 in the same execution. I suppose that's obvious now, but I guess I felt it necessary to correct your first example.

I personally use the regex pattern that lomcevak posted.

Please check your sample file again. You have string1 and string2 in TWO lines.

Of course you will not find string1 and string2 in the same line using your test. Try making a valid test file (or use the messages log) and you will see it works fine.

The OP wanted grep to match lines that contained string1 and string2 in the same execution.

No, that is *your* assumption and OP never made any such requirement.