# Constants

`nothing`

  The singleton instance of type `Void`, used by convention when there is no value to return (as in a C `void` function). Can be converted to an empty `Nullable` value.

`PROGRAM_FILE`

  A string containing the script name passed to Julia from the command line. Note that the script name remains unchanged from within included files. Alternatively see `@__FILE__`.

`ARGS`

  An array of the command line arguments passed to Julia, as strings.

`C_NULL`

  The C null pointer constant, sometimes used when calling external code.

`VERSION`

  A `VersionNumber` object describing which version of Julia is in use. For details see Version Number Literals.

`LOAD_PATH`

  An array of paths (as strings) where the `require` function looks for code.

`JULIA_HOME`

  A string containing the full path to the directory containing the `julia` executable.

`ANY`

  Equivalent to `Any` for dispatch purposes, but signals the compiler to skip code generation specialization for that field.

`Sys.``CPU_CORES`

  The number of logical CPU cores available in the system.

  See the Hwloc.jl package for extended information, including number of physical cores.

`Sys.``WORD_SIZE`

  Standard word size on the current machine, in bits.

`Sys.``KERNEL`

  A symbol representing the name of the operating system, as returned by `uname` of the build configuration.

`Sys.``ARCH`

  A symbol representing the architecture of the build configuration.

`Sys.``MACHINE`

  A string containing the build triple.

See also:

`STDIN` `STDOUT` `STDERR` `ENV` `ENDIAN_BOM` `Libc.MS_ASYNC` `Libc.MS_INVALIDATE` `Libc.MS_SYNC` `Libdl.DL_LOAD_PATH` `Libdl.RTLD_DEEPBIND` `Libdl.RTLD_LOCAL` `Libdl.RTLD_NOLOAD` `Libdl.RTLD_LAZY` `Libdl.RTLD_NOW` `Libdl.RTLD_GLOBAL` `Libdl.RTLD_NODELETE` `Libdl.RTLD_FIRST`