finding number of occurences in large text file in linux

I have a 17 GB txt file and i cannot seem to load it via vim. Researched on solutions provided here. However i do not seem to understand them very well and i am not good with linux or perl.

I understand i would have to use grep or something.

grep -oP "/^2" file 

I have tried up to this code but i cannot seem to find the solution to output the number of occurences without printing all the lines to screen

I would like to find the number of lines that starts with a digit 2 in the file and output the number to shell.

Answer

If you want to continue using PCRE:

grep -cP ^2 file

Using grep’s “basic regular expressions”:

grep -c ^2 file