• The core library
• The standard library
• The compiler front-end
• The unix library: Unix system calls
• The str library: regular expressions and string processing
• The threads library
• The dynlink library: dynamic loading and linking of object files
• Recently removed or moved libraries (Graphics, Bigarray, Num, LablTk)

Chapter 27The unix library: Unix system calls

The unix library makes many Unix system calls and system-related library functions available to OCaml programs. This chapter describes briefly the functions provided. Refer to sections 2 ‍and ‍3 of the Unix manual for more details on the behavior of these functions.

• Module Unix: Unix system calls
• Module UnixLabels: Labeled Unix system calls

Not all functions are provided by all Unix variants. If some functions are not available, they will raise Invalid_arg when called.

Programs that use the unix library must be linked as follows:

        ocamlc other options unix.cma other files
        ocamlopt other options unix.cmxa other files

For interactive use of the unix library, do:

        ocamlmktop -o mytop unix.cma
        ./mytop

or (if dynamic linking of C libraries is supported on your platform), start ocaml and type #load "unix.cma";;.

Windows:  The Cygwin port of OCaml fully implements all functions from the Unix module. The native Win32 ports implement a subset of them. Below is a list of the functions that are not implemented, or only partially implemented, by the Win32 ports. Functions not mentioned are fully implemented and behave as described previously in this chapter.