Sys.3o man page

Sys — System interface.


Module Sys


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 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.

val file_exists : string -> bool

Test if a file with the given name exists.

val is_directory : string -> bool

Returns 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.

Since 3.10.0

val remove : string -> unit

Remove the given file name from the file system.

val rename : string -> string -> unit

Rename a file. The first argument is the old name and the second is the new name. If there is already another file under the new name, rename may replace it, or raise an exception, depending on your operating system.

val getenv : string -> string

Return the value associated to a variable in the process environment. Raise Not_found if the variable is unbound.

val command : string -> int

Execute the given shell command and return its exit code.

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 ( . 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 Pervasives.ref

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 .

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).

val unix : bool

True if Sys.os_type = Unix .

Since 4.01.0

val win32 : bool

True if Sys.os_type = Win32 .

Since 4.01.0

val cygwin : bool

True if Sys.os_type = Cygwin .

Since 4.01.0

val word_size : int

Size of one word on the machine currently executing the OCaml program, in bits: 32 or 64.

val big_endian : bool

Whether the machine currently executing the Caml program is big-endian.

Since 4.00.0

val max_string_length : int

Maximum length of strings and byte sequences.

val max_array_length : int

Maximum 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.

=== 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 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 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. ===

val sigabrt : int

Abnormal termination

val sigalrm : int


val sigfpe : int

Arithmetic exception

val sighup : int

Hangup on controlling terminal

val sigill : int

Invalid hardware instruction

val sigint : int

Interactive interrupt (ctrl-C)

val sigkill : int

Termination (cannot be ignored)

val sigpipe : int

Broken pipe

val sigquit : int

Interactive termination

val sigsegv : int

Invalid memory reference

val sigterm : int


val sigusr1 : int

Application-defined signal 1

val sigusr2 : int

Application-defined signal 2

val sigchld : int

Child process terminated

val sigcont : int


val sigstop : int


val sigtstp : int

Interactive stop

val sigttin : int

Terminal read from background process

val sigttou : int

Terminal write from background process

val sigvtalrm : int

Timeout in virtual time

val sigprof : int

Profiling interrupt

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 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 : 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] and [+additional-info] parts may be absent.


OCamldoc OCaml library 2016-05-04