val argv : string array
The command line arguments given to the process. The first element is the command name used to invoke the program. The following elements are the command-line arguments given to the program.
val executable_name : string
The name of the file containing the executable currently running. This name may be absolute or relative to the current directory, depending on the platform and whether the program was compiled to bytecode or a native executable.
val is_directory : string -> bool
Returns
true
if the given name refers to a directory,false
if it refers to another kind of file. RaiseSys_error
if no file exists with the given name.- since
- 3.10.0
val rename : string -> string -> unit
Rename a file.
rename oldpath newpath
renames the file calledoldpath
, giving itnewpath
as its new name, moving it between directories if needed. Ifnewpath
already exists, its contents will be replaced with those ofoldpath
. Depending on the operating system, the metadata (permissions, owner, etc) ofnewpath
can either be preserved or be replaced by those ofoldpath
.- since
- 4.06 concerning the "replace existing file" behavior
val getenv : string -> string
Return the value associated to a variable in the process environment. Raise
Not_found
if the variable is unbound.
val getenv_opt : string -> string option
Return the value associated to a variable in the process environment or
None
if the variable is unbound.- since
- 4.05
val time : unit -> float
Return the processor time, in seconds, used by the program since the beginning of execution.
val readdir : string -> string array
Return the names of all files present in the given directory. Names denoting the current directory and the parent directory (
"."
and".."
in Unix) are not returned. Each string in the result is a file name rather than a complete path. There is no guarantee that the name strings in the resulting array will appear in any specific order; they are not, in particular, guaranteed to appear in alphabetical order.
val interactive : bool Stdlib.ref
This reference is initially set to
false
in standalone programs and totrue
if the code is being executed under the interactive toplevel systemocaml
.
val os_type : string
Operating system currently executing the OCaml program. One of
"Unix"
(for all Unix versions, including Linux and Mac OS X),"Win32"
(for MS-Windows, OCaml compiled with MSVC++ or Mingw),"Cygwin"
(for MS-Windows, OCaml compiled with Cygwin).
type backend_type =
| Native
| Bytecode
| Other of string
Currently, the official distribution only supports
Native
andBytecode
, but it can be other backends with alternative compilers, for example, javascript.- since
- 4.04.0
val backend_type : backend_type
Backend type currently executing the OCaml program.
- since
- 4.04.0
val word_size : int
Size of one word on the machine currently executing the OCaml program, in bits: 32 or 64.
val int_size : int
Size of
int
, in bits. It is 31 (resp. 63) when using OCaml on a 32-bit (resp. 64-bit) platform. It may differ for other implementations, e.g. it can be 32 bits when compiling to JavaScript.- since
- 4.03.0
val big_endian : bool
Whether the machine currently executing the Caml program is big-endian.
- since
- 4.00.0
val max_array_length : int
Maximum length of a normal array (i.e. any array whose elements are not of type
float
). The maximum length of afloat array
ismax_floatarray_length
if OCaml was configured with--enable-flat-float-array
andmax_array_length
if configured with--disable-flat-float-array
.
val max_floatarray_length : int
Maximum length of a floatarray. This is also the maximum length of a
float array
when OCaml is configured with--enable-flat-float-array
.
val runtime_variant : unit -> string
Return the name of the runtime variant the program is running on. This is normally the argument given to
-runtime-variant
at compile time, but for byte-code it can be changed after compilation.- since
- 4.03.0
val runtime_parameters : unit -> string
Return the value of the runtime parameters, in the same format as the contents of the
OCAMLRUNPARAM
environment variable.- since
- 4.03.0
Signal handling
type signal_behavior =
| Signal_default
| Signal_ignore
| Signal_handle of int -> unit
What to do when receiving a signal:
Signal_default
: take the default behavior (usually: abort the program)Signal_ignore
: ignore the signalSignal_handle f
: call functionf
, giving it the signal number as argument.
val signal : int -> signal_behavior -> signal_behavior
Set the behavior of the system on receipt of a given signal. The first argument is the signal number. Return the behavior previously associated with the signal. If the signal number is invalid (or not available on your system), an
Invalid_argument
exception is raised.
val set_signal : int -> signal_behavior -> unit
Same as
Sys.signal
but return value is ignored.
Signal numbers for the standard POSIX signals.
exception Break
Exception raised on interactive interrupt if
Sys.catch_break
is on.
val catch_break : bool -> unit
catch_break
governs whether interactive interrupt (ctrl-C) terminates the program or raises theBreak
exception. Callcatch_break true
to enable raisingBreak
, andcatch_break false
to let the system terminate the program on user interrupt.
val ocaml_version : string
ocaml_version
is the version of OCaml. It is a string of the form"major.minor[.patchlevel][+additional-info]"
, wheremajor
,minor
, andpatchlevel
are integers, andadditional-info
is an arbitrary string. The[.patchlevel]
and[+additional-info]
parts may be absent.
val enable_runtime_warnings : bool -> unit
Control whether the OCaml runtime system can emit warnings on stderr. Currently, the only supported warning is triggered when a channel created by
open_*
functions is finalized without being closed. Runtime warnings are enabled by default.- since
- 4.03.0
val runtime_warnings_enabled : unit -> bool
Return whether runtime warnings are currently enabled.
- since
- 4.03.0
Optimization
val opaque_identity : 'a -> 'a
For the purposes of optimization,
opaque_identity
behaves like an unknown (and thus possibly side-effecting) function.At runtime,
opaque_identity
disappears altogether.A typical use of this function is to prevent pure computations from being optimized away in benchmarking loops. For example:
for _round = 1 to 100_000 do ignore (Sys.opaque_identity (my_pure_computation ())) done
- since
- 4.03.0