Predefined Constants
PHP Manual

posix_sysconf constants

POSIX_SC_ARG_MAX (int)
The maximum number of bytes the arguments (and environment variables) can have. Available as of PHP 8.3.0.
POSIX_SC_PAGESIZE (int)
The number of bytes of the current page. Available as of PHP 8.3.0.
POSIX_SC_NPROCESSORS_CONF (int)
The number of cpus configured system wise. Available as of PHP 8.3.0.
POSIX_SC_NPROCESSORS_ONLN (int)
The number of cpus currently active system wise. Available as of PHP 8.3.0.