Every function in this module raises
Sys_error with an
informative message when the underlying system call signal
val argv :
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 :
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 file_exists :
string -> bool
Test if a file with the given name exists.
val is_directory :
string -> bool
true if the given name refers to a directory,
false if it refers to another kind of file.
Sys_errorif no file exists with the given name.
val remove :
string -> unit
Remove the given file name from the file system.
val rename :
string -> string -> unit
Rename a file.
rename oldpath newpath renames the file
oldpath, giving it
newpath as its new name,
moving it between directories if needed. If
exists, its contents will be replaced with those of
Depending on the operating system, the metadata (permissions,
owner, etc) of
newpath can either be preserved or be replaced by
val getenv :
string -> string
Return the value associated to a variable in the process environment.
Not_foundif the variable is unbound.
val getenv_opt :
string -> string option
Return the value associated to a variable in the process
None if the variable is unbound.
val 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
<, which will be honored by the
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.
Filename.quote_command performs the appropriate quoting
given a command name, a list of arguments, and optional file redirections.
val time :
unit -> float
Return the processor time, in seconds, used by the program since the beginning of execution.
val chdir :
string -> unit
Change the current working directory of the process.
val getcwd :
unit -> string
Return the current working directory of the process.
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
".." 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 :
This reference is initially set to
false in standalone
programs and to
true if the code is being executed under
the interactive toplevel system
val os_type :
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).
Currently, the official distribution only supports
Bytecode, but it can be other backends with alternative
val backend_type :
Backend type currently executing the OCaml program.
val unix :
Sys.os_type = "Unix".
val win32 :
Sys.os_type = "Win32".
val cygwin :
Sys.os_type = "Cygwin".
val word_size :
Size of one word on the machine currently executing the OCaml program, in bits: 32 or 64.
val int_size :
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,
val big_endian :
Whether the machine currently executing the Caml program is big-endian.
val max_string_length :
Maximum length of strings and byte sequences.
val max_array_length :
Maximum length of a normal array (i.e. any array whose elements are
not of type
float). The maximum length of a
max_floatarray_length if OCaml was configured with
max_array_length if configured
val max_floatarray_length :
Maximum length of a floatarray. This is also the maximum length of
float array when OCaml is configured with
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.
val runtime_parameters :
unit -> string
Return the value of the runtime parameters, in the same format
as the contents of the
OCAMLRUNPARAM environment variable.
What to do when receiving a signal:
Signal_default: take the default behavior (usually: abort the program)
Signal_ignore: ignore the signal
Signal_handle f: call function
f, 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
exception is raised.
val set_signal :
int -> signal_behavior -> unit
Sys.signal but return value is ignored.
val sigabrt :
val sigalrm :
val sigfpe :
val sighup :
Hangup on controlling terminal
val sigill :
Invalid hardware instruction
val sigint :
Interactive interrupt (ctrl-C)
val sigkill :
Termination (cannot be ignored)
val sigpipe :
val sigquit :
val sigsegv :
Invalid memory reference
val sigterm :
val sigusr1 :
Application-defined signal 1
val sigusr2 :
Application-defined signal 2
val sigchld :
Child process terminated
val sigcont :
val sigstop :
val sigtstp :
val sigttin :
Terminal read from background process
val sigttou :
Terminal write from background process
val sigvtalrm :
Timeout in virtual time
val sigprof :
val sigbus :
val sigpoll :
val sigsys :
Bad argument to routine
val sigtrap :
val sigurg :
Urgent condition on socket
val sigxcpu :
Timeout in cpu time
val sigxfsz :
File size limit exceeded
Exception raised on interactive interrupt if
val catch_break :
bool -> unit
catch_break governs whether interactive interrupt (ctrl-C)
terminates the program or raises the
catch_break true to enable raising
catch_break false to let the system
terminate the program on user interrupt.
val ocaml_version :
ocaml_version is the version of OCaml.
It is a string of the form
patchlevel are integers, and
additional-info is an arbitrary string.
[.patchlevel] part is absent for versions anterior to 3.08.0.
[(+|~)additional-info] part 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 disabled by default.
val runtime_warnings_enabled :
unit -> bool
Return whether runtime warnings are currently enabled.
val opaque_identity :
'a -> 'a
For the purposes of optimization,
opaque_identity behaves like an
unknown (and thus possibly side-effecting) function.
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