sh search for files that contain code example

Example 1: find text in linux file

grep 'word' filename
grep 'word' file1 file2 file3
grep 'string1 string2'  filename
cat otherfile | grep 'something'
command | grep 'something'
command option1 | grep 'data'
grep --color 'data' fileName

Example 2: linux find file

# syntax 
# find *</path/to/dir> '(' *<Filter-1> *<and/or-operator> *<filter-2> ')'

# example 
find . '(' -name "Test*.pm" -a ! -name 'Useless*' ')'