using bash shell, how can I search for a particular file in a folder (and its sub-folders)
would find all the files that end in "sh" in that directory.
would find all files with "readme" in their names regardless of capitalization in that directory and its subdirectories.
There are two ways to do this.
If slocate is installed and the database is up to date you can use "locate pattern | grep /path/you/wish/tosearch"
This is faster than the find command if you're searching a large directory or directories.
The other more traditional method is using the find command as Dennis has already pointed out so I won't go into that one.