https://manpages.ubuntu.com/manpages/noble/man3/iscntrl.3.html
Ubuntu Manpage: isalnum, isalpha, isascii, isblank, iscntrl, isdigit, isgraph,
ubuntumanpageisblank
https://manpages.ubuntu.com/manpages/noble/man3/isxdigit.3.html
Ubuntu Manpage: isalnum, isalpha, isascii, isblank, iscntrl, isdigit, isgraph,
ubuntumanpageisblank
https://learn.microsoft.com/en-us/cpp/c-runtime-library/reference/isgraph-iswgraph-isgraph-l-iswgraph-l?view=msvc-170
isgraph, iswgraph, _isgraph_l, _iswgraph_l | Microsoft Learn
Learn more about: isgraph, iswgraph, _isgraph_l, _iswgraph_l
iswgraphlmicrosoft
https://www.php.net/manual/tr/intlchar.isgraph.php
PHP: IntlChar::isgraph - Manual
Check if code point is a graphic character
phpmanual
https://manpages.ubuntu.com/manpages/focal/de/man3/isupper.3.html
Ubuntu Manpage: isalnum, isalpha, isascii, isblank, iscntrl, isdigit, isgraph,
ubuntumanpageisblank
https://www.php.net/manual/it/intlchar.isgraph.php
PHP: IntlChar::isgraph - Manual
Check if code point is a graphic character
phpmanual