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.
let argv: array(string);
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.
let 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.
let file_exists: string => bool;
Test if a file with the given name exists.
let is_directory: string => bool;
Returns true
if the given name refers to a directory,
false
if it refers to another kind of file.
Sys_error
if no file exists with the given name.let remove: string => unit;
Remove the given file name from the file system.
let rename: (string, string) => unit;
Rename 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
.
let getenv: string => string;
Return the value associated to a variable in the process environment.
Not_found
if the variable is unbound.let getenv_opt: string => option(string);
Return the value associated to a variable in the process
environment or None
if the variable is unbound.
let command: string => int;
Execute the given shell command and return its exit code.
The argument of Sys.command
is generally the name of a
command followed by zero, one or several arguments, separated
by whitespace. The given argument is interpreted by a
shell: either the Windows shell cmd.exe
for the Win32 ports of
OCaml, or the POSIX shell sh
for other ports. It can contain
shell builtin commands such as echo
, and also special characters
such as file redirections >
and <
, which will be honored by the
shell.
Conversely, whitespace or special shell characters occurring in
command names or in their arguments must be quoted or escaped
so that the shell does not interpret them. The quoting rules vary
between the POSIX shell and the Windows shell.
The Filename.quote_command
performs the appropriate quoting
given a command name, a list of arguments, and optional file redirections.
let time: unit => float;
Return the processor time, in seconds, used by the program since the beginning of execution.
let chdir: string => unit;
Change the current working directory of the process.
let mkdir: (string, int) => unit;
Create a directory with the given permissions.
let rmdir: string => unit;
Remove an empty directory.
let getcwd: unit => string;
Return the current working directory of the process.
let readdir: string => array(string);
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.
let interactive: ref(bool);
This reference is initially set to false
in standalone
programs and to true
if the code is being executed under
the interactive toplevel system ocaml
.
let 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
and
Bytecode
, but it can be other backends with alternative
compilers, for example, javascript.
let backend_type: backend_type;
Backend type currently executing the OCaml program.
let unix: bool;
True if Sys.os_type = "Unix"
.
let win32: bool;
True if Sys.os_type = "Win32"
.
let cygwin: bool;
True if Sys.os_type = "Cygwin"
.
let word_size: int;
Size of one word on the machine currently executing the OCaml program, in bits: 32 or 64.
let 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.
let big_endian: bool;
Whether the machine currently executing the Caml program is big-endian.
let max_string_length: int;
Maximum length of strings and byte sequences.
let 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 a float array
is max_floatarray_length
if OCaml was configured with
--enable-flat-float-array
and max_array_length
if configured
with --disable-flat-float-array
.
let 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
.
let 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.
let runtime_parameters: unit => string;
Return 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 (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 function f
, giving it the signal
number as argument.let 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.
let set_signal: (int, signal_behavior) => unit;
Same as Sys.signal
but return value is ignored.
let sigabrt: int;
Abnormal termination
let sigalrm: int;
Timeout
let sigfpe: int;
Arithmetic exception
let sighup: int;
Hangup on controlling terminal
let sigill: int;
Invalid hardware instruction
let sigint: int;
Interactive interrupt (ctrl-C)
let sigkill: int;
Termination (cannot be ignored)
let sigpipe: int;
Broken pipe
let sigquit: int;
Interactive termination
let sigsegv: int;
Invalid memory reference
let sigterm: int;
Termination
let sigusr1: int;
Application-defined signal 1
let sigusr2: int;
Application-defined signal 2
let sigchld: int;
Child process terminated
let sigcont: int;
Continue
let sigstop: int;
Stop
let sigtstp: int;
Interactive stop
let sigttin: int;
Terminal read from background process
let sigttou: int;
Terminal write from background process
let sigvtalrm: int;
Timeout in virtual time
let sigprof: int;
Profiling interrupt
let sigbus: int;
Bus error
let sigpoll: int;
Pollable event
let sigsys: int;
Bad argument to routine
let sigtrap: int;
Trace/breakpoint trap
let sigurg: int;
Urgent condition on socket
let sigxcpu: int;
Timeout in cpu time
let sigxfsz: int;
File size limit exceeded
exception Break;
Exception raised on interactive interrupt if Sys.catch_break
is on.
let catch_break: bool => unit;
catch_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.
let ocaml_version: string;
ocaml_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]
part is absent for versions anterior to 3.08.0.
The [(+|~)additional-info]
part may be absent.
let 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 disabled by default.
let runtime_warnings_enabled: unit => bool;
Return whether runtime warnings are currently enabled.
let 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
module Immediate64: sig .. end