Module Stdlib.SysSource

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.

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.

Test if a file with the given name exists.

Returns true if the given name refers to a directory, false if it refers to another kind of file.

• raises Sys_error

  if no file exists with the given name.

• since 3.10

Returns true if the given name refers to a regular file, false if it refers to another kind of file.

• raises Sys_error

  if no file exists with the given name.

• since 5.1

Remove the given file name from the file system.

Rename a file or directory. rename oldpath newpath renames the file or directory called oldpath, giving it newpath as its new name, moving it between (parent) directories if needed. If a file named 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.

• since 4.06 concerning the "replace existing file" behavior

Return the value associated to a variable in the process environment.

• raises Not_found

  if the variable is unbound.

Return the value associated to a variable in the process environment or None if the variable is unbound.

• since 4.05

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.

Return the processor time, in seconds, used by the program since the beginning of execution.

Change the current working directory of the process.

Create a directory with the given permissions.

• since 4.12

Remove an empty directory.

• since 4.12

Return the current working directory of the process.

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.

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.

• alert unsynchronized_access The interactive status is a mutable global state.

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-w64),
• "Cygwin" (for MS-Windows, OCaml compiled with Cygwin).

Currently, the official distribution only supports Native and Bytecode, but it can be other backends with alternative compilers, for example, javascript.

• since 4.04

Backend type currently executing the OCaml program.

• since 4.04

True if Sys.os_type = "Unix".

• since 4.01

True if Sys.os_type = "Win32".

• since 4.01

True if Sys.os_type = "Cygwin".

• since 4.01

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

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

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

• since 4.00

Maximum length of strings and byte sequences.

Maximum length of a normal array (i.e. any array whose elements are not unboxed and 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.

Maximum length of a floatarray. This is also the maximum length of a float array when OCaml is configured with --enable-flat-float-array.

Maximum length of a float# array. Equivalent to max_floatarray_length.

Maximum length of a float32# array. In non-native backends, equal to max_array_length.

Maximum length of a int64# array. In non-native backends, equal to max_array_length.

Maximum length of a int32# array. In non-native backends, equal to max_array_length.

Maximum length of a int16# array. In non-native backends, equal to max_array_length.

Maximum length of a int8# array. In non-native backends, equal to max_array_length.

Maximum length of a int8 array. In non-native backends, equal to max_array_length.

Maximum length of a nativeint# array. In non-native backends, equal to max_array_length.

Maximum length of an unboxed 128-bit simd vector array. Only supported in 64-bit native code.

Maximum length of an unboxed 256-bit simd vector array. Only supported in 64-bit native code.

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

Return the value of the runtime parameters, in the same format as the contents of the OCAMLRUNPARAM environment variable.

• since 4.03

Run any pending runtime actions, such as minor collections, major GC slices, signal handlers, finalizers, or memprof callbacks.

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.

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.

• alert unsafe_multidomain Use [Sys.Safe.signal].

Same as Sys.signal but return value is ignored.

• alert unsafe_multidomain Use [Sys.Safe.set_signal].

Abnormal termination

Timeout

Arithmetic exception

Hangup on controlling terminal

Invalid hardware instruction

Interactive interrupt (ctrl-C)

Termination (cannot be ignored)

Broken pipe

Interactive termination

Invalid memory reference

Termination

Application-defined signal 1

Application-defined signal 2

Child process terminated

Continue

Stop

Interactive stop

Terminal read from background process

Terminal write from background process

Timeout in virtual time

Profiling interrupt

Bus error

• since 4.03

Pollable event

• since 4.03

Bad argument to routine

• since 4.03

Trace/breakpoint trap

• since 4.03

Urgent condition on socket

• since 4.03

Timeout in cpu time

• since 4.03

File size limit exceeded

• since 4.03

Exception raised on interactive interrupt if Sys.catch_break is enabled.

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.

By default, having done catch_break true, Break will be delivered to the toplevel uncaught exception handler. To deliver it elsewhere, use with_async_exns, below.

Inside multi-threaded programs, the Break exception will arise in any one of the active threads, and will keep arising on further interactive interrupt until all threads are terminated. Use signal masks from Thread.sigmask to direct the interrupt towards a specific thread.

with_async_exns f runs f and returns its result, in addition to causing any asynchronous Break or Stack_overflow exceptions (e.g. from finalisers, signal handlers or the GC) to be raised from the call site of with_async_exns.

The asynchronous exception handler context is per-domain, not per-fiber: delimited continuations do not capture it.

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 was absent before version 3.08.0 and became mandatory from 3.08.0 onwards. The [(+|~)additional-info] part may be absent.

true if this is a development version, false otherwise.

• since 4.14

• since 4.14

• since 4.14

ocaml_release is the version of OCaml.

• since 4.14

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.

• since 4.03

• alert unsynchronized_access The status of runtime warnings is a mutable global state.

Return whether runtime warnings are currently enabled.

• since 4.03

• alert unsynchronized_access The status of runtime warnings is a mutable global state.

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

This module allows to define a type t with the immediate64 attribute. This attribute means that the type is immediate on 64 bit architectures. On other architectures, it might or might not be immediate.

Submodule containing non-backwards-compatible functions which enforce thread safety via modes.

True if Sys.arch = Amd64.

True if Sys.arch = Arm64.