(PHP 8 >= 8.3.0)
posix_pathconf — Returns the value of a configurable limit
This function is currently not documented; only its argument list is available.
   Returns the value of a configurable limit from name for a path
  
pathThe name of the file whose limit you want to get.
name
       The name of the configurable limit, one of the following.
       POSIX_PC_LINK_MAX, POSIX_PC_MAX_CANON,
       POSIX_PC_MAX_INPUT, POSIX_PC_NAME_MAX,
       POSIX_PC_PATH_MAX, POSIX_PC_PIPE_BUF,
       POSIX_PC_CHOWN_RESTRICTED, POSIX_PC_NO_TRUNC,
       POSIX_PC_ALLOC_SIZE_MIN, POSIX_PC_SYMLINK_MAX.
      
   Returns the configurable limit or false.
  
   Throws a ValueError
   when path is empty.
  
Example #1 posix_pathconf() example
This example will get the max path name's length in bytes for the tmp dir.
<?php
echo posix_pathconf(sys_get_temp_dir(), POSIX_PC_PATH_MAX);
?>The above example will output:
4096
