find file

find . -name 'mystring*'

find /home/username/ -name "*.err"

Extremely useful command!!
In Mac and Linux: Define directory where to search as "." for current directory
and then specify the name or regex of file or folder to find.

find . -name "foo*"  

In Windows: Define "/s" for a recursively search and name or regex of file or
folgder to search

dir /s "foo*"

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

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