using find to search for files code example
Example 1: find linux with extension
find /home/username/ -name "*.err"
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*' ')'