$ echo -n joe.smith@aol.com | sha256sum
4d1612632ab95a0dec3d27f521d2b91cabe9e72a6b1ecdb8784e1ed6f3a93604  -
$ perl -MDigest::SHA=sha256_hex -E 'say sha256_hex(q/joe.smith@aol.com/)'
4d1612632ab95a0dec3d27f521d2b91cabe9e72a6b1ecdb8784e1ed6f3a93604

##</code><code>##

$ perl -wE 'use Digest::SHA "sha256_hex"; say sha256_hex("joe.smith@aol.com")'
Possible unintended interpolation of @aol in string at -e line 1.
Name "main::aol" used only once: possible typo at -e line 1.
4ea2142392947d467539285b3c6e98f073d9d85910f2a1d535f86a95358ab9dd
$ perl -Mstrict -wE 'use Digest::SHA "sha256_hex"; say sha256_hex("joe.smith@aol.com")'
Possible unintended interpolation of @aol in string at -e line 1.
Global symbol "@aol" requires explicit package name (did you forget to declare "my @aol"?) at -e line 1.
Execution of -e aborted due to compilation errors.