Recuperation de libunix de CL0.7

git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@6 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02

1 files changed, 831 insertions, 0 deletions

diff --git a/otherlibs/unix/unix.mli b/otherlibs/unix/unix.mli
new file mode 100644
index 000000000..a102e5330
--- /dev/null
+++ b/otherlibs/unix/unix.mli
@@ -0,0 +1,831 @@
+(* Interface to the Unix system *)
+
+(*** Error report *)
+
+type error =
+    ENOERR
+  | EPERM               (* Not owner *)
+  | ENOENT              (* No such file or directory *)
+  | ESRCH               (* No such process *)
+  | EINTR               (* Interrupted system call *)
+  | EIO                 (* I/O error *)
+  | ENXIO               (* No such device or address *)
+  | E2BIG               (* Arg list too long *)
+  | ENOEXEC             (* Exec format error *)
+  | EBADF               (* Bad file number *)
+  | ECHILD              (* No children *)
+  | EAGAIN              (* No more processes *)
+  | ENOMEM              (* Not enough core *)
+  | EACCES              (* Permission denied *)
+  | EFAULT              (* Bad address *)
+  | ENOTBLK             (* Block device required *)
+  | EBUSY               (* Mount device busy *)
+  | EEXIST              (* File exists *)
+  | EXDEV               (* Cross-device link *)
+  | ENODEV              (* No such device *)
+  | ENOTDIR             (* Not a directory*)
+  | EISDIR              (* Is a directory *)
+  | EINVAL              (* Invalid argument *)
+  | ENFILE              (* File table overflow *)
+  | EMFILE              (* Too many open files *)
+  | ENOTTY              (* Not a typewriter *)
+  | ETXTBSY             (* Text file busy *)
+  | EFBIG               (* File too large *)
+  | ENOSPC              (* No space left on device *)
+  | ESPIPE              (* Illegal seek *)
+  | EROFS               (* Read-only file system *)
+  | EMLINK              (* Too many links *)
+  | EPIPE               (* Broken pipe *)
+  | EDOM                (* Argument too large *)
+  | ERANGE              (* Result too large *)
+  | EWOULDBLOCK         (* Operation would block *)
+  | EINPROGRESS         (* Operation now in progress *)
+  | EALREADY            (* Operation already in progress *)
+  | ENOTSOCK            (* Socket operation on non-socket *)
+  | EDESTADDRREQ        (* Destination address required *)
+  | EMSGSIZE            (* Message too long *)
+  | EPROTOTYPE          (* Protocol wrong type for socket *)
+  | ENOPROTOOPT         (* Protocol not available *)
+  | EPROTONOSUPPORT     (* Protocol not supported *)
+  | ESOCKTNOSUPPORT     (* Socket type not supported *)
+  | EOPNOTSUPP          (* Operation not supported on socket *)
+  | EPFNOSUPPORT        (* Protocol family not supported *)
+  | EAFNOSUPPORT        (* Address family not supported by protocol family *)
+  | EADDRINUSE          (* Address already in use *)
+  | EADDRNOTAVAIL       (* Can't assign requested address *)
+  | ENETDOWN            (* Network is down *)
+  | ENETUNREACH         (* Network is unreachable *)
+  | ENETRESET           (* Network dropped connection on reset *)
+  | ECONNABORTED        (* Software caused connection abort *)
+  | ECONNRESET          (* Connection reset by peer *)
+  | ENOBUFS             (* No buffer space available *)
+  | EISCONN             (* Socket is already connected *)
+  | ENOTCONN            (* Socket is not connected *)
+  | ESHUTDOWN           (* Can't send after socket shutdown *)
+  | ETOOMANYREFS        (* Too many references: can't splice *)
+  | ETIMEDOUT           (* Connection timed out *)
+  | ECONNREFUSED        (* Connection refused *)
+  | ELOOP               (* Too many levels of symbolic links *)
+  | ENAMETOOLONG        (* File name too long *)
+  | EHOSTDOWN           (* Host is down *)
+  | EHOSTUNREACH        (* No route to host *)
+  | ENOTEMPTY           (* Directory not empty *)
+  | EPROCLIM            (* Too many processes *)
+  | EUSERS              (* Too many users *)
+  | EDQUOT              (* Disc quota exceeded *)
+  | ESTALE              (* Stale NFS file handle *)
+  | EREMOTE             (* Too many levels of remote in path *)
+  | EIDRM               (* Identifier removed *)
+  | EDEADLK             (* Deadlock condition. *)
+  | ENOLCK              (* No record locks available. *)
+  | ENOSYS              (* Function not implemented *)
+  | EUNKNOWNERR
+
+        (* The type of error codes. *)
+
+exception Unix_error of error * string * string
+        (* Raised by the system calls below when an error is encountered.
+           The first component is the error code; the second component
+           is the function name; the third component is the string parameter
+           to the function, if it has one, or the empty string otherwise. *)
+
+external error_message : error -> string = "unix_error_message"
+        (* Return a string describing the given error code. *)
+
+val handle_unix_error : ('a -> 'b) -> 'a -> 'b
+        (* [handle_unix_error f x] applies [f] to [x] and returns the result.
+           If the exception [Unix_error] is raised, it prints a message
+           describing the error and exits with code 2. *)
+
+
+(*** Interface with the parent process *)
+
+external environment : unit -> string array = "unix_environment"
+        (* Return the process environment, as an array of strings
+           with the format ``variable=value''. See also [sys__getenv]. *)
+
+(*** Process handling *)
+
+type process_status =
+    WEXITED of int
+  | WSIGNALED of int * bool
+  | WSTOPPED of int
+
+        (* The termination status of a process. [WEXITED] means that the
+           process terminated normally by [exit]; the argument is the return
+           code. [WSIGNALED] means that the process was killed by a signal;
+           the first argument is the signal number, the second argument
+           indicates whether a ``core dump'' was performed. [WSTOPPED] means
+           that the process was stopped by a signal; the argument is the
+           signal number. *)
+
+type wait_flag =
+    WNOHANG
+  | WUNTRACED
+
+        (* Flags for [waitopt] and [waitpid].
+           [WNOHANG] means do not block if no child has
+           died yet, but immediately return with a pid equal to 0.
+           [WUNTRACED] means report also the children that receive stop
+           signals. *)
+
+external execv : string -> string array -> unit = "unix_execv"
+        (* [execv prog args] execute the program in file [prog], with
+           the arguments [args], and the current process environment. *)
+external execve : string -> string array -> string array -> unit = "unix_execve"
+        (* Same as [execv], except that the third argument provides the
+           environment to the program executed. *)
+external execvp : string -> string array -> unit = "unix_execvp"
+        (* Same as [execv], except that the program is searched in the path. *)
+external fork : unit -> int = "unix_fork"
+        (* Fork a new process. The returned integer is 0 for the child
+           process, the pid of the child process for the parent process. *)
+external wait : unit -> int * process_status = "unix_wait"
+        (* Wait until one of the children processes die, and return its pid
+           and termination status. *)
+external waitpid : wait_flag list -> int -> int * process_status
+           = "unix_waitpid"
+        (* Same as [waitopt], but waits for the process whose pid is given.
+           Negative pid arguments represent process groups. *)
+val system : string -> process_status
+        (* Execute the given command, wait until it terminates, and return
+           its termination status. The string is interpreted by the shell
+           [/bin/sh] and therefore can contain redirections, quotes, variables,
+           etc. The result [WEXITED 127] indicates that the shell couldn't
+           be executed. *)
+external getpid : unit -> int = "unix_getpid"
+        (* Return the pid of the process. *)
+external getppid : unit -> int = "unix_getppid"
+        (* Return the pid of the parent process. *)
+external nice : int -> int = "unix_nice"
+        (* Change the process priority. The integer argument is added to the
+           ``nice'' value. (Higher values of the ``nice'' value mean
+           lower priorities.) Return the new nice value. *)
+
+
+(*** Basic file input/output *)
+
+type file_descr
+        (* The abstract type of file descriptors. *)
+
+val stdin : file_descr
+val stdout : file_descr
+val stderr : file_descr
+        (* File descriptors for standard input, standard output and
+           standard error. *)
+
+
+type open_flag =
+    O_RDONLY                            (* Open for reading *)
+  | O_WRONLY                            (* Open for writing *)
+  | O_RDWR                              (* Open for reading and writing *)
+  | O_NDELAY                            (* Open in non-blocking mode *)
+  | O_APPEND                            (* Open for append *)
+  | O_CREAT                             (* Create if nonexistent *)
+  | O_TRUNC                             (* Truncate to 0 length if existing *)
+  | O_EXCL                              (* Fail if existing *)
+
+        (* The flags to [open]. *)
+
+type file_perm = int
+        (* The type of file access rights. *)
+
+external openfile : string -> open_flag list -> file_perm -> file_descr
+           = "unix_open"
+        (* Open the named file with the given flags. Third argument is
+           the permissions to give to the file if it is created. Return
+           a file descriptor on the named file. *)
+external close : file_descr -> unit = "unix_close"
+        (* Close a file descriptor. *)
+external read : file_descr -> string -> int -> int -> int = "unix_read"
+        (* [read fd buff start len] reads [len] characters from descriptor
+           [fd], storing them in string [buff], starting at position [ofs]
+           in string [buff]. Return the number of characters actually read. *)
+external write : file_descr -> string -> int -> int -> int = "unix_write"
+        (* [write fd buff start len] writes [len] characters to descriptor
+           [fd], taking them from string [buff], starting at position [ofs]
+           in string [buff]. Return the number of characters actually
+           written. *)
+
+
+(*** Interfacing with the standard input/output library (module io). *)
+
+external in_channel_of_descr : file_descr -> in_channel = "open_descriptor"
+        (* Create an input channel reading from the given descriptor. *)
+external out_channel_of_descr : file_descr -> out_channel = "open_descriptor"
+        (* Create an output channel writing on the given descriptor. *)
+external descr_of_in_channel : in_channel -> file_descr = "channel_descriptor"
+        (* Return the descriptor corresponding to an input channel. *)
+external descr_of_out_channel : out_channel -> file_descr = "channel_descriptor"
+        (* Return the descriptor corresponding to an output channel. *)
+
+
+(*** Seeking and truncating *)
+
+type seek_command =
+    SEEK_SET
+  | SEEK_CUR
+  | SEEK_END
+
+        (* Positioning modes for [lseek]. [SEEK_SET] indicates positions
+           relative to the beginning of the file, [SEEK_CUR] relative to
+           the current position, [SEEK_END] relative to the end of the
+           file. *)
+
+external lseek : file_descr -> int -> seek_command -> int = "unix_lseek"
+        (* Set the current position for a file descriptor *)
+external truncate : string -> int -> unit = "unix_truncate"
+        (* Truncates the named file to the given size. *)
+external ftruncate : file_descr -> int -> unit = "unix_ftruncate"
+        (* Truncates the file corresponding to the given descriptor
+           to the given size. *)
+
+
+(*** File statistics *)
+
+type file_kind =
+    S_REG                               (* Regular file *)
+  | S_DIR                               (* Directory *)
+  | S_CHR                               (* Character device *)
+  | S_BLK                               (* Block device *)
+  | S_LNK                               (* Symbolic link *)
+  | S_FIFO                              (* Named pipe *)
+  | S_SOCK                              (* Socket *)
+
+type stats =
+  { st_dev : int;                       (* Device number *)
+    st_ino : int;                       (* Inode number *)
+    st_kind : file_kind;                (* Kind of the file *)
+    st_perm : file_perm;                (* Access rights *)
+    st_nlink : int;                     (* Number of links *)
+    st_uid : int;                       (* User id of the owner *)
+    st_gid : int;                       (* Group id of the owner *)
+    st_rdev : int;                      (* Device minor number *)
+    st_size : int;                      (* Size in bytes *)
+    st_atime : int;                     (* Last access time *)
+    st_mtime : int;                     (* Last modification time *)
+    st_ctime : int }                    (* Last status change time *)
+
+        (* The informations returned by the [stat] calls. *)
+
+external stat : string -> stats = "unix_stat"
+        (* Return the information for the named file. *)
+external lstat : string -> stats = "unix_lstat"
+        (* Same as [stat], but in case the file is a symbolic link,
+           return the information for the link itself. *)
+external fstat : file_descr -> stats = "unix_fstat"
+        (* Return the information for the file associated with the given
+           descriptor. *)
+
+
+(*** Operations on file names *)
+
+external unlink : string -> unit = "unix_unlink"
+        (* Removes the named file *)
+external rename : string -> string -> unit = "unix_rename"
+        (* [rename old new] changes the name of a file from [old] to [new]. *)
+external link : string -> string -> unit = "unix_link"
+        (* [link source dest] creates a hard link named [dest] to the file
+           named [new]. *)
+
+
+(*** File permissions and ownership *)
+
+type access_permission =
+    R_OK                                (* Read permission *)
+  | W_OK                                (* Write permission *)
+  | X_OK                                (* Execution permission *)
+  | F_OK                                (* File exists *)
+
+        (* Flags for the [access] call. *)
+
+external chmod : string -> file_perm -> unit = "unix_chmod"
+        (* Change the permissions of the named file. *) 
+external fchmod : file_descr -> file_perm -> unit = "unix_fchmod"
+        (* Change the permissions of an opened file. *) 
+external chown : string -> int -> int -> unit = "unix_chown"
+        (* Change the owner uid and owner gid of the named file. *) 
+external fchown : file_descr -> int -> int -> unit = "unix_fchown"
+        (* Change the owner uid and owner gid of an opened file. *) 
+external umask : int -> int = "unix_umask"
+        (* Set the process creation mask, and return the previous mask. *)
+external access : string -> access_permission list -> unit = "unix_access"
+        (* Check that the process has the given permissions over the named
+           file. Raise [Unix_error] otherwise. *)
+
+
+(*** File descriptor hacking *)
+
+external fcntl_int : file_descr -> int -> int -> int = "unix_fcntl_int"
+        (* Interface to [fcntl] in the case where the argument is an
+           integer. The first integer argument is the command code;
+           the second is the integer parameter. *)
+external fcntl_ptr : file_descr -> int -> string -> int = "unix_fcntl_ptr"
+        (* Interface to [fcntl] in the case where the argument is a pointer.
+           The integer argument is the command code. A pointer to the string
+           argument is passed as argument to the command. The string argument
+           is usually set up with the functions from modules [peek] and
+           [poke]. *)
+
+
+(*** Directories *)
+
+external mkdir : string -> file_perm -> unit = "unix_mkdir"
+        (* Create a directory with the given permissions. *)
+external rmdir : string -> unit = "unix_rmdir"
+        (* Remove an empty directory. *)
+external chdir : string -> unit = "unix_chdir"
+        (* Change the process working directory. *)
+external getcwd : unit -> string = "unix_getcwd"
+        (* Return the name of the current working directory. *)
+
+
+type dir_handle
+
+        (* The type of descriptors over opened directories. *)
+
+external opendir : string -> dir_handle = "unix_opendir"
+        (* Open a descriptor on a directory *)
+external readdir : dir_handle -> string = "unix_readdir"
+        (* Return the next entry in a directory.
+           Raise [End_of_file] when the end of the directory has been 
+           reached. *)
+external rewinddir : dir_handle -> unit = "unix_rewinddir"
+        (* Reposition the descriptor to the beginning of the directory *)
+external closedir : dir_handle -> unit = "unix_closedir"
+        (* Close a directory descriptor. *)
+
+
+(*** Pipes and redirections *)
+
+external pipe : unit -> file_descr * file_descr = "unix_pipe"
+        (* Create a pipe. The first component of the result is opened
+           for reading, that's the exit to the pipe. The second component is
+           opened for writing, that's the entrace to the pipe. *) 
+external dup : file_descr -> file_descr = "unix_dup"
+        (* Duplicate a descriptor. *)
+external dup2 : file_descr -> file_descr -> unit = "unix_dup2"
+        (* [dup2 fd1 fd2] duplicates [fd1] to [fd2], closing [fd2] if already
+           opened. *)
+
+
+val open_process_in: string -> in_channel
+val open_process_out: string -> out_channel
+val open_process: string -> in_channel * out_channel
+        (* High-level pipe and process management. These functions
+           run the given command in parallel with the program,
+           and return channels connected to the standard input and/or
+           the standard output of the command. The command is interpreted
+           by the shell [/bin/sh] (cf. [system]). Warning: writes on channels
+           are buffered, hence be careful to call [flush] at the right times
+           to ensure correct synchronization. *)
+val close_process_in: in_channel -> process_status
+val close_process_out: out_channel -> process_status
+val close_process: in_channel * out_channel -> process_status
+        (* Close channels opened by [open_process_in], [open_process_out]
+           and [open_process], respectively, wait for the associated
+           command to terminate, and return its termination status. *)
+
+
+(*** Symbolic links *)
+
+external symlink : string -> string -> unit = "unix_symlink"
+        (* [symlink source dest] creates the file [dest] as a symbolic link
+           to the file [source]. *)
+external readlink : string -> string = "unix_readlink"
+        (* Read the contents of a link. *)
+
+
+(*** Named pipes *)
+
+external mkfifo : string -> file_perm -> unit = "unix_mkfifo"
+        (* Create a named pipe with the given permissions. *)
+
+
+(*** Special files *)
+
+external ioctl_int : file_descr -> int -> int -> int = "unix_ioctl_int"
+        (* Interface to [ioctl] in the case where the argument is an
+           integer. The first integer argument is the command code;
+           the second is the integer parameter. *)
+external ioctl_ptr : file_descr -> int -> string -> int = "unix_ioctl_ptr"
+        (* Interface to [ioctl] in the case where the argument is a pointer.
+           The integer argument is the command code. A pointer to the string
+           argument is passed as argument to the command. The string argument
+           is usually set up with the functions from modules [peek] and
+           [poke]. *)
+
+
+(*** Polling *)
+
+external select :
+  file_descr list -> file_descr list -> file_descr list -> float ->
+        file_descr list * file_descr list * file_descr list = "unix_select"
+
+        (* Wait until some input/output operations become possible on
+           some channels. The three list arguments are, respectively, a set
+           of descriptors to check for reading (first argument), for writing
+           (second argument), or for exceptional conditions (third argument).
+           The fourth argument is the maximal timeout, in seconds; a
+           negative fourth argument means no timeout (unbounded wait).
+           The result is composed of three sets of descriptors: those ready
+           for reading (first component), ready for writing (second component),
+           and over which an exceptional condition is pending (third
+           component). *)
+
+(*** Locking *)
+
+type lock_command =
+    F_ULOCK               (* Unlock a region *)
+  | F_LOCK                (* Lock a region, and block if already locked *)
+  | F_TLOCK               (* Lock a region, or fail if already locked *)
+  | F_TEST                (* Test a region for other process' locks *)
+
+        (* Commands for [lockf]. *)
+
+external lockf : file_descr -> lock_command -> int -> unit = "unix_lockf"
+
+        (* [lockf fd cmd size] puts a lock on a region of the file opened
+           as [fd]. The region starts at the current read/write position for
+           [fd] (as set by [lseek]), and extends [size] bytes forward if
+           [size] is positive, [size] bytes backwards if [size] is negative,
+           or to the end of the file if [size] is zero. *)
+
+(*** Signals *)
+
+external kill : int -> int -> unit = "unix_kill"
+        (* [kill pid sig] sends signal number [sig] to the process
+           with id [pid]. *)
+external pause : unit -> unit = "unix_pause"
+        (* Wait until a non-ignored signal is delivered. *)
+
+
+(*** Time functions *)
+
+type process_times =
+  { tms_utime : float;          (* User time for the process *)
+    tms_stime : float;          (* System time for the process *)
+    tms_cutime : float;         (* User time for the children processes *)
+    tms_cstime : float }        (* System time for the children processes *)
+
+        (* The execution times (CPU times) of a process. *)
+
+type tm =
+  { tm_sec : int;                       (* Seconds 0..59 *)
+    tm_min : int;                       (* Minutes 0..59 *)
+    tm_hour : int;                      (* Hours 0..23 *)
+    tm_mday : int;                      (* Day of month 1..31 *)
+    tm_mon : int;                       (* Month of year 0..11 *)
+    tm_year : int;                      (* Year - 1900 *)
+    tm_wday : int;                      (* Day of week (Sunday is 0) *)
+    tm_yday : int;                      (* Day of year 0..365 *)
+    tm_isdst : bool }                   (* Daylight time savings in effect *)
+
+        (* The type representing wallclock time and calendar date. *)
+
+external time : unit -> int = "unix_time"
+        (* Return the current time since 00:00:00 GMT, Jan. 1, 1970,
+           in seconds. *)
+external gmtime : int -> tm = "unix_gmtime"
+        (* Convert a time in seconds, as returned by [time], into a date and
+           a time. Assumes Greenwich meridian time zone. *)
+external localtime : int -> tm = "unix_localtime"
+        (* Convert a time in seconds, as returned by [time], into a date and
+           a time. Assumes the local time zone. *)
+external alarm : int -> int = "unix_alarm"
+        (* Schedule a [SIGALRM] signals after the given number of seconds. *)
+external sleep : int -> unit = "unix_sleep"
+        (* Stop execution for the given number of seconds. *)
+external times : unit -> process_times = "unix_times"
+        (* Return the execution times of the process. *)
+external utimes : string -> int -> int -> unit = "unix_utimes"
+        (* Set the last access time (second arg) and last modification time
+           (third arg) for a file. Times are expressed in seconds from
+           00:00:00 GMT, Jan. 1, 1970. *)
+
+
+(*** User id, group id *)
+
+external getuid : unit -> int = "unix_getuid"
+        (* Return the user id of the user executing the process. *)
+external geteuid : unit -> int = "unix_geteuid"
+        (* Return the effective user id under which the process runs. *)
+external setuid : int -> unit = "unix_setuid"
+        (* Set the real user id and effective user id for the process. *)
+external getgid : unit -> int = "unix_getgid"
+        (* Return the group id of the user executing the process. *)
+external getegid : unit -> int = "unix_getegid"
+        (* Return the effective group id under which the process runs. *)
+external setgid : int -> unit = "unix_setgid"
+        (* Set the real group id and effective group id for the process. *)
+external getgroups : unit -> int array = "unix_getgroups"
+        (* Return the list of groups to which the user executing the process
+           belongs. *)
+
+
+type passwd_entry =
+  { pw_name : string;
+    pw_passwd : string;
+    pw_uid : int;
+    pw_gid : int;
+    pw_gecos : string;
+    pw_dir : string;
+    pw_shell : string }
+        (* Structure of entries in the [passwd] database. *)
+
+type group_entry =
+  { gr_name : string;
+    gr_passwd : string;
+    gr_gid : int;
+    gr_mem : string array }
+        (* Structure of entries in the [groups] database. *)
+
+external getlogin : unit -> string = "unix_getlogin"
+        (* Return the login name of the user executing the process. *)
+external getpwnam : string -> passwd_entry = "unix_getpwnam"
+        (* Find an entry in [passwd] with the given name, or raise
+           [Not_found]. *)
+external getgrnam : string -> group_entry = "unix_getgrnam"
+        (* Find an entry in [group] with the given name, or raise
+           [Not_found]. *)
+external getpwuid : int -> passwd_entry = "unix_getpwuid"
+        (* Find an entry in [passwd] with the given user id, or raise
+           [Not_found]. *)
+external getgrgid : int -> group_entry = "unix_getgrgid"
+        (* Find an entry in [group] with the given group id, or raise
+           [Not_found]. *)
+
+
+(*** Internet addresses *)
+
+type inet_addr
+        (* The abstract type of Internet addresses. *)
+
+external inet_addr_of_string : string -> inet_addr
+                                    = "unix_inet_addr_of_string"
+external string_of_inet_addr : inet_addr -> string
+                                    = "unix_string_of_inet_addr"
+        (* Conversions between string with the format [XXX.YYY.ZZZ.TTT]
+           and Internet addresses. [inet_addr_of_string] raises [Failure]
+           when given a string that does not match this format. *)
+
+
+(*** Sockets *)
+
+type socket_domain =
+    PF_UNIX                             (* Unix domain *)
+  | PF_INET                             (* Internet domain *)
+
+        (* The type of socket domains. *)
+
+type socket_type =
+    SOCK_STREAM                         (* Stream socket *)
+  | SOCK_DGRAM                          (* Datagram socket *)
+  | SOCK_RAW                            (* Raw socket *)
+  | SOCK_SEQPACKET                      (* Sequenced packets socket *)
+
+        (* The type of socket kinds, specifying the semantics of
+           communications. *)
+
+type sockaddr =
+    ADDR_UNIX of string
+  | ADDR_INET of inet_addr * int
+
+        (* The type of socket addresses. [ADDR_UNIX name] is a socket
+           address in the Unix domain; [name] is a file name in the file
+           system. [ADDR_INET(addr,port)] is a socket address in the Internet
+           domain; [addr] is the Internet address of the machine, and
+           [port] is the port number. *)
+
+type shutdown_command =
+    SHUTDOWN_RECEIVE                    (* Close for receiving *)
+  | SHUTDOWN_SEND                       (* Close for sending *)
+  | SHUTDOWN_ALL                        (* Close both *)
+
+        (* The type of commands for [shutdown]. *)
+
+type msg_flag =
+    MSG_OOB
+  | MSG_DONTROUTE
+  | MSG_PEEK
+
+        (* The flags for [recv], [recvfrom], [send] and [sendto]. *)
+
+external socket : socket_domain -> socket_type -> int -> file_descr
+                                  = "unix_socket"
+        (* Create a new socket in the given domain, and with the
+           given kind. The third argument is the protocol type; 0 selects
+           the default protocol for that kind of sockets. *)
+external socketpair :
+        socket_domain -> socket_type -> int -> file_descr * file_descr
+                                  = "unix_socketpair"
+        (* Create a pair of unnamed sockets, connected together. *)
+external accept : file_descr -> file_descr * sockaddr = "unix_accept"
+        (* Accept connections on the given socket. The returned descriptor
+           is a socket connected to the client; the returned address is
+           the address of the connecting client. *)
+external bind : file_descr -> sockaddr -> unit = "unix_bind"
+        (* Bind a socket to an address. *)
+external connect : file_descr -> sockaddr -> unit = "unix_connect"
+        (* Connect a socket to an address. *)
+external listen : file_descr -> int -> unit = "unix_listen"
+        (* Set up a socket for receiving connection requests. The integer
+           argument is the maximal number of pending requests. *)
+external shutdown : file_descr -> shutdown_command -> unit = "unix_shutdown" 
+        (* Shutdown a socket connection. [SHUTDOWN_SEND] as second argument
+           causes reads on the other end of the connection to return
+           an end-of-file condition.
+           [SHUTDOWN_RECEIVE] causes writes on the other end of the connection
+           to return a closed pipe condition ([SIGPIPE] signal). *)
+external recv : file_descr -> string -> int -> int -> msg_flag list -> int
+                                  = "unix_recv"
+external recvfrom :
+        file_descr -> string -> int -> int -> msg_flag list -> int * sockaddr
+                                  = "unix_recvfrom"
+        (* Receive data from an unconnected socket. *)
+external send : file_descr -> string -> int -> int -> msg_flag list -> int
+                                  = "unix_send"
+external sendto :
+        file_descr -> string -> int -> int -> msg_flag list -> sockaddr -> int
+                                  = "unix_sendto"
+        (* Send data over an unconnected socket. *)
+
+
+(*** High-level network connection functions *)
+
+val open_connection : sockaddr -> in_channel * out_channel
+        (* Connect to a server at the given address.
+           Return a pair of buffered channels connected to the server.
+           Remember to call [flush] on the output channel at the right times
+           to ensure correct synchronization. *)
+val shutdown_connection : in_channel -> unit
+        (* ``Shut down'' a connection established with [open_connection];
+           that is, transmit an end-of-file condition to the server reading
+           on the other side of the connection. *)
+val establish_server : (in_channel -> out_channel -> 'a) -> sockaddr -> unit
+        (* Establish a server on the given address.
+           The function given as first argument is called for each connection
+           with two buffered channels connected to the client. A new process
+           is created for each connection. The function [establish_server]
+           never returns normally. *)
+
+
+(*** Host and protocol databases *)
+
+type host_entry =
+  { h_name : string;
+    h_aliases : string array;
+    h_addrtype : socket_domain;
+    h_addr_list : inet_addr array }
+          (* Structure of entries in the [hosts] database. *)
+
+type protocol_entry =
+  { p_name : string;
+    p_aliases : string array;
+    p_proto : int }
+          (* Structure of entries in the [protocols] database. *)
+
+type service_entry =
+  { s_name : string;
+    s_aliases : string array;
+    s_port : int;
+    s_proto : string }
+          (* Structure of entries in the [services] database. *)
+
+external gethostname : unit -> string = "unix_gethostname"
+        (* Return the name of the local host. *)
+external gethostbyname : string -> host_entry = "unix_gethostbyname"
+        (* Find an entry in [hosts] with the given name, or raise
+           [Not_found]. *)
+external gethostbyaddr : inet_addr -> host_entry = "unix_gethostbyaddr"
+        (* Find an entry in [hosts] with the given address, or raise
+           [Not_found]. *)
+external getprotobyname : string -> protocol_entry
+                                         = "unix_getprotobyname"
+        (* Find an entry in [protocols] with the given name, or raise
+           [Not_found]. *)
+external getprotobynumber : int -> protocol_entry
+                                         = "unix_getprotobynumber"
+        (* Find an entry in [protocols] with the given protocol number,
+           or raise [Not_found]. *)
+external getservbyname : string -> string -> service_entry
+                                         = "unix_getservbyname"
+        (* Find an entry in [services] with the given name, or raise
+           [Not_found]. *)
+external getservbyport : int -> string -> service_entry
+                                         = "unix_getservbyport"
+        (* Find an entry in [services] with the given service number,
+           or raise [Not_found]. *)
+
+
+(*** Terminal interface *)
+
+(* The following functions implement the POSIX standard terminal
+   interface. They provide control over asynchronous communication ports
+   and pseudo-terminals. Refer to the [termios] man page for a
+   complete description. *)
+
+type terminal_io = {
+  (* Input modes: *)
+    mutable c_ignbrk: bool;  (* Ignore the break condition. *)
+    mutable c_brkint: bool;  (* Signal interrupt on break condition. *)
+    mutable c_ignpar: bool;  (* Ignore characters with parity errors. *)
+    mutable c_parmrk: bool;  (* Mark parity errors. *)
+    mutable c_inpck: bool;   (* Enable parity check on input. *)
+    mutable c_istrip: bool;  (* Strip 8th bit on input characters. *)
+    mutable c_inlcr: bool;   (* Map NL to CR on input. *)
+    mutable c_igncr: bool;   (* Ignore CR on input. *)
+    mutable c_icrnl: bool;   (* Map CR to NL on input. *)
+    mutable c_ixon: bool;    (* Recognize XON/XOFF characters on input. *)
+    mutable c_ixoff: bool;   (* Emit XON/XOFF chars to control input flow. *)
+  (* Output modes: *)
+    mutable c_opost: bool;   (* Enable output processing. *)
+    mutable c_olcuc: bool;   (* Map lowercase to uppercase on output. *)
+    mutable c_onlcr: bool;   (* Map NL to CR/NL on output. *)
+    mutable c_ocrnl: bool;   (* Map CR to NL on output. *)
+    mutable c_onocr: bool;   (* No CR output at column 0. *)
+    mutable c_onlret: bool;  (* NL is assumed to perform as CR. *)
+    mutable c_ofill: bool;   (* Use fill characters instead of delays. *)
+    mutable c_ofdel: bool;   (* Fill character is DEL instead of NULL. *)
+    mutable c_nldly: int;    (* Newline delay type (0-1). *)
+    mutable c_crdly: int;    (* Carriage return delay type (0-3). *)
+    mutable c_tabdly: int;   (* Horizontal tab delay type (0-3). *)
+    mutable c_bsdly: int;    (* Backspace delay type (0-1). *)
+    mutable c_vtdly: int;    (* Vertical tab delay type (0-1). *)
+    mutable c_ffdly: int;    (* Form feed delay type (0-1). *)
+  (* Control modes: *)
+    mutable c_obaud: int;    (* Output baud rate (0 means close connection).*)
+    mutable c_ibaud: int;    (* Input baud rate. *)
+    mutable c_csize: int;    (* Number of bits per character (5-8). *)
+    mutable c_cstopb: int;   (* Number of stop bits (1-2). *)
+    mutable c_cread: bool;   (* Reception is enabled. *)
+    mutable c_parenb: bool;  (* Enable parity generation and detection. *)
+    mutable c_parodd: bool;  (* Specify odd parity instead of even. *)
+    mutable c_hupcl: bool;   (* Hang up on last close. *)
+    mutable c_clocal: bool;  (* Ignore modem status lines. *)
+  (* Local modes: *)
+    mutable c_isig: bool;    (* Generate signal on INTR, QUIT, SUSP. *)
+    mutable c_icanon: bool;  (* Enable canonical processing
+                                (line buffering and editing) *)
+    mutable c_noflsh: bool;  (* Disable flush after INTR, QUIT, SUSP. *)
+    mutable c_echo: bool;    (* Echo input characters. *)
+    mutable c_echoe: bool;   (* Echo ERASE (to erase previous character). *)
+    mutable c_echok: bool;   (* Echo KILL (to erase the current line). *)
+    mutable c_echonl: bool;  (* Echo NL even if c_echo is not set. *)
+  (* Control characters: *)
+    mutable c_vintr: char;   (* Interrupt character (usually ctrl-C). *)
+    mutable c_vquit: char;   (* Quit character (usually ctrl-\). *)
+    mutable c_verase: char;  (* Erase character (usually DEL or ctrl-H). *)
+    mutable c_vkill: char;   (* Kill line character (usually ctrl-U). *)
+    mutable c_veof: char;    (* End-of-file character (usually ctrl-D). *)
+    mutable c_veol: char;    (* Alternate end-of-line char. (usually none). *)
+    mutable c_vmin: int;     (* Minimum number of characters to read
+                                before the read request is satisfied. *)
+    mutable c_vtime: int;    (* Maximum read wait (in 0.1s units). *)
+    mutable c_vstart: char;  (* Start character (usually ctrl-Q). *)
+    mutable c_vstop: char    (* Stop character (usually ctrl-S). *)
+  }
+
+external tcgetattr: file_descr -> terminal_io = "unix_tcgetattr"
+        (* Return the status of the terminal referred to by the given
+           file descriptor. *)
+
+type setattr_when = TCSANOW | TCSADRAIN | TCSAFLUSH
+
+external tcsetattr: file_descr -> setattr_when -> terminal_io -> unit
+               = "unix_tcsetattr"
+        (* Set the status of the terminal referred to by the given
+           file descriptor. The second argument indicates when the
+           status change takes place: immediately ([TCSANOW]),
+           when all pending output has been transmitted ([TCSADRAIN]),
+           or after flushing all input that has been received but not
+           read ([TCSAFLUSH]). [TCSADRAIN] is recommended when changing
+           the output parameters; [TCSAFLUSH], when changing the input
+           parameters. *)
+
+external tcsendbreak: file_descr -> int -> unit = "unix_tcsendbreak"
+        (* Send a break condition on the given file descriptor.
+           The second argument is the duration of the break, in 0.1s units;
+           0 means standard duration (0.25s). *)
+
+external tcdrain: file_descr -> unit = "unix_tcdrain"
+        (* Waits until all output written on the given file descriptor
+           has been transmitted. *)
+
+type flush_queue = TCIFLUSH | TCOFLUSH | TCIOFLUSH
+
+external tcflush: file_descr -> flush_queue -> unit = "unix_tcflush"
+        (* Discard data written on the given file descriptor but not yet
+           transmitted, or data received but not yet read, depending on the
+           second argument: [TCIFLUSH] flushes data received but not read,
+           [TCOFLUSH] flushes data written but not transmitted, and
+           [TCIOFLUSH] flushes both. *)
+
+type flow_action = TCOOFF | TCOON | TCIOFF | TCION
+
+external tcflow: file_descr -> flow_action -> unit = "unix_tcflow"
+        (* Suspend or restart reception or transmission of data on
+           the given file descriptor, depending on the second argument:
+           [TCOOFF] suspends output, [TCOON] restarts output,
+           [TCIOFF] transmits a STOP character to suspend input,
+           and [TCION] transmits a START character to restart input. *)