module Sys:sig..end
System interface.
Every function in this module raises Sys_error with an
informative message when the underlying system call signal
an error.
val argv : string arrayThe 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 : stringThe 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 file_exists : string -> boolTest if a file with the given name exists.
val is_directory : string -> boolReturns true if the given name refers to a directory,
false if it refers to another kind of file.
Raise Sys_error if no file exists with the given name.
val remove : string -> unitRemove the given file name from the file system.
val rename : string -> string -> unitRename a file. rename oldpath newpath renames the file
called oldpath, giving it newpath as its new name,
moving it between directories if needed. If newpath already
exists, its contents will be replaced with those of oldpath.
Depending on the operating system, the metadata (permissions,
owner, etc) of newpath can either be preserved or be replaced by
those of oldpath.
val getenv : string -> stringReturn the value associated to a variable in the process
environment. Raise Not_found if the variable is unbound.
val getenv_opt : string -> string optionReturn the value associated to a variable in the process
environment or None if the variable is unbound.
val command : string -> intExecute the given shell command and return its exit code.
val time : unit -> floatReturn the processor time, in seconds, used by the program since the beginning of execution.
val chdir : string -> unitChange the current working directory of the process.
val getcwd : unit -> stringReturn the current working directory of the process.
val readdir : string -> string arrayReturn 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 refThis reference is initially set to false in standalone
programs and to true if the code is being executed under
the interactive toplevel system ocaml.
val os_type : stringOperating 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 |
Currently, the official distribution only supports Native and
Bytecode, but it can be other backends with alternative
compilers, for example, javascript.
val backend_type : backend_typeBackend type currently executing the OCaml program.
val unix : boolTrue if Sys.os_type = "Unix".
val win32 : boolTrue if Sys.os_type = "Win32".
val cygwin : boolTrue if Sys.os_type = "Cygwin".
val word_size : intSize of one word on the machine currently executing the OCaml program, in bits: 32 or 64.
val int_size : intSize 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.
val big_endian : boolWhether the machine currently executing the Caml program is big-endian.
val max_string_length : intMaximum length of strings and byte sequences.
val max_array_length : intMaximum length of a normal array. The maximum length of a float
array is max_array_length/2 on 32-bit machines and
max_array_length on 64-bit machines.
val runtime_variant : unit -> stringReturn 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.
val runtime_parameters : unit -> stringReturn the value of the runtime parameters, in the same format
as the contents of the OCAMLRUNPARAM environment variable.
type signal_behavior =
| |
Signal_default |
| |
Signal_ignore |
| |
Signal_handle of |
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 function f, giving it the signal
number as argument.val signal : int -> signal_behavior -> signal_behaviorSet 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 -> unitSame as Sys.signal but return value is ignored.
val sigabrt : intAbnormal termination
val sigalrm : intTimeout
val sigfpe : intArithmetic exception
val sighup : intHangup on controlling terminal
val sigill : intInvalid hardware instruction
val sigint : intInteractive interrupt (ctrl-C)
val sigkill : intTermination (cannot be ignored)
val sigpipe : intBroken pipe
val sigquit : intInteractive termination
val sigsegv : intInvalid memory reference
val sigterm : intTermination
val sigusr1 : intApplication-defined signal 1
val sigusr2 : intApplication-defined signal 2
val sigchld : intChild process terminated
val sigcont : intContinue
val sigstop : intStop
val sigtstp : intInteractive stop
val sigttin : intTerminal read from background process
val sigttou : intTerminal write from background process
val sigvtalrm : intTimeout in virtual time
val sigprof : intProfiling interrupt
val sigbus : intBus error
val sigpoll : intPollable event
val sigsys : intBad argument to routine
val sigtrap : intTrace/breakpoint trap
val sigurg : intUrgent condition on socket
val sigxcpu : intTimeout in cpu time
val sigxfsz : intFile size limit exceeded
exception Break
Exception raised on interactive interrupt if Sys.catch_break
is on.
val catch_break : bool -> unitcatch_break governs whether interactive interrupt (ctrl-C)
terminates the program or raises the Break exception.
Call catch_break true to enable raising Break,
and catch_break false to let the system
terminate the program on user interrupt.
val ocaml_version : stringocaml_version is the version of OCaml.
It is a string of the form "major.minor[.patchlevel][+additional-info]",
where major, minor, and patchlevel are integers, and
additional-info is an arbitrary string. The [.patchlevel] and
[+additional-info] parts may be absent.
val enable_runtime_warnings : bool -> unitControl 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.
val runtime_warnings_enabled : unit -> boolReturn whether runtime warnings are currently enabled.
val opaque_identity : 'a -> 'aFor 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