$*IN
variable dynamic
filehandle for STDIN (standard input)
https://docs.raku.org/language/variables#Special_filehandles:_STDIN,_STDOUT_and_STDERR
The file handle for reading input, e.g. with C<.lines> or C<.slurp>.

$*OUT
variable dynamic
filehandle for STDOUT (standard output)
https://docs.raku.org/language/variables#Special_filehandles:_STDIN,_STDOUT_and_STDERR
The file handle for writing standard output to, e.g. with C<say>.

$*ERR
variable dynamic
filehandle for STDERR (error output)
https://docs.raku.org/language/variables#Special_filehandles:_STDIN,_STDOUT_and_STDERR
The file handle for writing error output to, e.g. with C<note>.

%*ENV
variable dynamic hash
access to operating system environment variables
https://docs.raku.org/language/variables#%*ENV
A hash that contains all of the environment variables of the operating
system when Raku is started.  May be altered.  Serves as a default for
environment variables for any forked process.

$*INIT-INSTANT
variable dynamic
when Raku was started
https://docs.raku.org/language/variables#$*INIT-INSTANT
The C<Instant> the raku process was started.

$*CWD
variable dynamic
what should be considered the default directory
https://docs.raku.org/language/variables#$*CWD
An C<IO::Path> object that contains the directory that should be
considered to be the current working directory.  Initialized with the
OS's current directory at startup.

$*PID
variable dynamic integer
the Process IDentifier
https://docs.raku.org/language/variables#$*PID
An integer value for the PID of the current process.

$*PROGRAM-NAME
variable dynamic string
name of current Raku program
https://docs.raku.org/language/variables#$*PROGRAM-NAME
A string presentation of the path of the currently executing Raku
program.

$*PROGRAM
variable dynamic
current Raku program
https://docs.raku.org/language/variables#$*PROGRAM
An C<IO::Path> of the currently executing Raku program.  Available at
compile time, and can thus be used as part of a C<use lib> statement.
=begin code :lang<raku>
use lib $*PROGRAM.sibling("lib");
=end code

$*EXECUTABLE
variable dynamic
currently running Raku runtime
https://docs.raku.org/language/variables#$*EXECUTABLE
An C<IO::Path> of the currently running Raku executable (typically
"rakudo").  Can be used as the initial argument to e.g. C<run>.

$*USER
variable dynamic integer string
the current user
https://docs.raku.org/language/variables#$*USER
An C<IntStr> with information about the current user (uid and name).

$*GROUP
variable dynamic integer string
the group of the current user
https://docs.raku.org/language/variables#$*GROUP
An C<IntStr> with group information about the current user (gid and
name) if supported by the operating system.


contains all variables that are always available either in the dynamic
scope (looking up the callstack), or in the C<GLOBAL::> or C<PROCESS::>
stashes.  All of these variable can be shadowed by lexically defined
variables with the same name.
