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.
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: A fairly complete emulation of the Unix system calls is provided in the Windows version of OCaml. The end of this chapter gives more information on the functions that are not supported under Windows.
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.
Functions Comment fork not implemented, use create_process or threads wait not implemented, use waitpid waitpid can only wait for a given PID, not any child process getppid not implemented (meaningless under Windows) nice not implemented truncate, ftruncate not implemented link, symlink, readlink not implemented (no links under Windows) access execute permission X_OK cannot be tested, it just tests for read permission instead fchmod not implemented chown, fchown not implemented (make no sense on a DOS file system) umask not implemented set_nonblock, clear_nonblock implemented as dummy functions; use threads instead of non-blocking I/O rewinddir not implemented; re-open the directory instead mkfifo not implemented kill, pause not implemented (no inter-process signals in Windows) alarm, times not implemented getitimer, setitimer not implemented getuid, getgid always return 1 getgid, getegid, getgroups not implemented setuid, setgid not implemented getpwnam, getpwuid always raise Not_found getgrnam, getgrgid always raise Not_found type socket_domain the domains PF_UNIX and PF_INET6 are not supported; PF_INET is fully supported establish_server not implemented; use threads terminal functions (tc*) not implemented