Remove underscore and capitalize character after it
Your suggestion 's/_/\U\1/g' is very close. If you have the GNU sed, then the following should work:
sed 's/_\(.\)/\U\1/g'(I say should, because what you wish for is not always what you want.)
Perl script:
use String::CamelCase qw(camelize);while (<>) { print camelize($_);}
Little more verbose from awk but it will work on all gnu/non-gnu Unix flavors:
> s='get_employee_Name'> awk -F _ '{printf "%s", $1; for(i=2; i<=NF; i++) printf "%s", toupper(substr($i,1,1)) substr($i, 2); print"";}' <<< "$s"getEmployeeName