grep first match code example

Example 1: grep first occurence for many matches

Just use flag -m to define number of occurrences to match:
grep -m1 pattern file

Example 2: grep second match

#Combine grep and tail for grepping until second match and filtering 
#last with tail command
grep -m2 "two" in-file.txt | tail -n1

Example 3: grep first match

Just combine grep with head command for filtering  only the first match as:
grep "match" | head -n 1   #Change 1 to not only match first but further matches