How to grep lines that end with .c or .cpp?

Question

I have a file as below, I want to grep for lines having .c or .cpp extension. I have tried using cat file|grep ".c" grep but I am getting all types of extensions as output. Please shed some light on this. Thanks in advance.

file contents are below:
/dir/a/b/cds/main.c
/dir/a/f/cmdss/file.cpp
/dir/a/b/cds/main.h
/dir/a/f/cmdss/file.hpp
/dir/a/b/cdys/main_abc.c
/dir/a/f/cmfs/file_123.cpp

Answer 1

grep supports regular expressions.

$ grep -E '\.(c|cpp)$' input

• -E means 'Interpret PATTERN as an extended regular expression'
• \. means a dot .
• () is a group
• c|cpp is an alternative
• $ is the lineend