To find all the files of a certain extension within the current path you can use the following
find syntax. It works by making use of
glob construct to match all the names having the
find /directory/to/search -maxdepth 1 -type f -name "*.extension"
To find all files of type
.txt from the current directory alone, do
find . -maxdepth 1 -type f -name "*.txt"