grep a particular content before a period

Question

I am trying to read/grep a particular word or content that is before a period (.).

e.g. file1 has abinaya.ashok and I want to grep whatever is before the period (.) without hardcoding anything.

if I try

grep \.\ file1  

it gives abinaya.ashok. I've tried: grep\*\.\ file1

it doesn't give anything.Can we find it using grep commands or should we do it only using awk command? Any thoughts?

Answer 1

Using GNU grep for PCRE regex (for non-greedy and positive look-ahead), you can do:

echo 'abinaya.ashok' | grep -oP '.*?(?=\.)'
abinaya

Using awk:

echo 'abinaya.ashok' | awk -F\. '{print $1}'
abinaya