Tail grep what tools are for it

Question

I would like to run the following command:

tail -f /var/log/syslog | grep -ri 00:16:CB:1E:AF:CA

In Linux but it does not working. How would you interactively grep certain text from log files?

Duplicate question http://stackoverflow.com/q/7161821 – squareborg Sep 30 '14 at 08:22 — squareborg, Sep 30 '14 at 08:22

score 3 · Answer 1 · answered Sep 30 '14 at 08:07

3

grep -r (recursive) makes no sense in your case, since you are just searching in a single file. Just use tail -f /var/log/syslog | grep -i 00:16:CB:1E:AF:CA.

answered Sep 30 '14 at 08:07

unlink

700
7
12

If applied to a single file, `tail` and `tail -r` are equivalent. `-r` might be redundant, but omiting it won't help. – Nils Toedtmann Sep 30 '14 at 08:11
What? `tail -r`? I just corrected `grep -ri` which **IS** wrong. – unlink Sep 30 '14 at 08:14
Oh dear ... i did mean `grep` of course. Still: Why is `grep -ri` wrong? – Nils Toedtmann Sep 30 '14 at 08:26
3

Well, I don't know your setup but on my Debian Wheezy `tail -f file | grep -ri something` also starts searching in every file in the directory I'm in. – unlink Sep 30 '14 at 08:38
You are of course correct - sorry! Need more coffee. – Nils Toedtmann Sep 30 '14 at 08:40

thanasisk · Answer 2 · 2014-09-30T09:17:09.997

1

As per stackoverflow

tailf file | grep --line-buffered 00:16:CB:1E:AF:CA

should do the trick

edited Sep 30 '14 at 09:17

answered Sep 30 '14 at 09:08

thanasisk

941
6
16

Tail grep what tools are for it

2 Answers2