echo $SHELL
uname -a

The SHELL variable will not necessarily tell you what shell is being used to execute the script, and the system is irrelevant to this script.

function newrecord () {

It is acceptable in bash, but it is neither standard nor ksh.

(Functions appeared first in ksh, with the syntax function funcname { ... }; then Bourne added functions to his shell using what is now the standard syntax, funcname() { ... }.

newrecord () {

No, I am perfectly serious. The "Unix shell" is, by definition, the POSIX shell. There are various implementations of the standard shell (bash, dash, ksh93), and some have a number of additions. There are also other shells (rc, etc.) that do not implement the standard Unix shell.