Unix grep regex how to grep for

Question

Hi

I have a text file

$ cat test.log
SYB-01001
SYB-18913
SYB-02445
SYB-21356

I want to grep for 01001 and 18913 only whats the way to do this

I want the output to be

SYB-01001
SYB-18913
SYB-02445

I tried this but not sure whats wrong with it

grep 'SYB-(18913)|0*)' test.log

Answer 1

Use the -E flag for "extended regular expressions" with grep.

e.g.

grep -E 'SYB-(0|18913)' test.log

Other things to be aware of:

• parentheses must match (for every opening bracket you want a closing bracket)
• 0* means zero or more 0 characters - in truth this will match everything

Answer 2

Try that :

grep 'SYB-\(18913\|0*\)' test.log

But you maybe don't want the 0* part to act like this. Maybe 0+ is better.

Answer 3

Your brackets are out. Try

grep 'SYB-[18913|0*]' test.log

Answer 4

awk

awk '/SYB-(0|18913)/' file