The unix library: Unix system calls
The unix library makes many Unix
system calls and system-related library functions available to
Objective Caml 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.
- Unix:
-
Programs that use the unix library must be linked in ``custom
runtime'' mode, as follows:
ocamlc -custom other options unix.cma other files -cclib -lunix
ocamlopt other options unix.cmxa other files -cclib -lunix
For interactive use of the unix library, do:
ocamlmktop -custom -o mytop unix.cma -cclib -lunix
./mytop
- Windows:
-
A fairly complete emulation of the Unix system calls is provided in
the Windows version of Objective Caml. The end of this chapter gives
more information on the functions that are not supported under Windows.
Programs that use the unix library must be linked in ``custom
runtime'' mode, as follows:
ocamlc -custom other options unix.cma other files \
%CAMLLIB%/libunix.lib wsock32.lib
ocamlopt other options unix.cmxa other files \
%CAMLLIB%/libunix.lib wsock32.lib
For interactive use of the unix library, do:
ocamlmktop -custom -o mytop.exe unix.cma \
%CAMLLIB%/libunix.lib wsock32.lib
mytop.exe
Module Unix: interface to the Unix system
Error report
type error =
-
Errors defined in the POSIX standard
E2BIG (* Argument list too long *)
| EACCES (* Permission denied *)
| EAGAIN (* Resource temporarily unavailable; try again *)
| EBADF (* Bad file descriptor *)
| EBUSY (* Resource unavailable *)
| ECHILD (* No child process *)
| EDEADLK (* Resource deadlock would occur *)
| EDOM (* Domain error for math functions, etc. *)
| EEXIST (* File exists *)
| EFAULT (* Bad address *)
| EFBIG (* File too large *)
| EINTR (* Function interrupted by signal *)
| EINVAL (* Invalid argument *)
| EIO (* Hardware I/O error *)
| EISDIR (* Is a directory *)
| EMFILE (* Too many open files by the process *)
| EMLINK (* Too many links *)
| ENAMETOOLONG (* Filename too long *)
| ENFILE (* Too many open files in the system *)
| ENODEV (* No such device *)
| ENOENT (* No such file or directory *)
| ENOEXEC (* Not an executable file *)
| ENOLCK (* No locks available *)
| ENOMEM (* Not enough memory *)
| ENOSPC (* No space left on device *)
| ENOSYS (* Function not supported *)
| ENOTDIR (* Not a directory *)
| ENOTEMPTY (* Directory not empty *)
| ENOTTY (* Inappropriate I/O control operation *)
| ENXIO (* No such device or address *)
| EPERM (* Operation not permitted *)
| EPIPE (* Broken pipe *)
| ERANGE (* Result too large *)
| EROFS (* Read-only file system *)
| ESPIPE (* Invalid seek e.g. on a pipe *)
| ESRCH (* No such process *)
| EXDEV (* Invalid link *)
-
Additional errors, mostly BSD
| 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 *)
| EHOSTDOWN (* Host is down *)
| EHOSTUNREACH (* No route to host *)
| ELOOP (* Too many levels of symbolic links *)
-
All other errors are mapped to EUNKNOWNERR
| EUNKNOWNERR (* Unknown error *)
-
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.
val error_message : error -> string
-
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
val environment : unit -> string array
-
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
| 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 argument is the signal number. 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.
val execv : string -> string array -> unit
-
execv prog args execute the program in file prog, with
the arguments args, and the current process environment.
val execve : string -> string array -> string array -> unit
-
Same as execv, except that the third argument provides the
environment to the program executed.
val execvp : string -> string array -> unit
val execvpe : string -> string array -> string array -> unit
-
Same as execv and execvp respectively, except that
the program is searched in the path.
val fork : unit -> int
-
Fork a new process. The returned integer is 0 for the child
process, the pid of the child process for the parent process.
val wait : unit -> int * process_status
-
Wait until one of the children processes die, and return its pid
and termination status.
val waitpid : wait_flag list -> int -> int * process_status
-
Same as wait, but waits for the process whose pid is given.
A pid of -1 means wait for any child.
A pid of 0 means wait for any child in the same process group
as the current process.
Negative pid arguments represent process groups.
The list of options indicates whether waitpid should return
immediately without waiting, or also report stopped children.
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.
val getpid : unit -> int
-
Return the pid of the process.
val getppid : unit -> int
-
Return the pid of the parent process.
val nice : int -> int
-
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_NONBLOCK (* 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.
val openfile : string -> open_flag list -> file_perm -> file_descr
-
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.
val close : file_descr -> unit
-
Close a file descriptor.
val read : file_descr -> string -> int -> int -> int
-
read fd buff ofs 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.
val write : file_descr -> string -> int -> int -> int
-
write fd buff ofs 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.
val in_channel_of_descr : file_descr -> in_channel
-
Create an input channel reading from the given descriptor.
val out_channel_of_descr : file_descr -> out_channel
-
Create an output channel writing on the given descriptor.
val descr_of_in_channel : in_channel -> file_descr
-
Return the descriptor corresponding to an input channel.
val descr_of_out_channel : out_channel -> file_descr
-
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.
val lseek : file_descr -> int -> seek_command -> int
-
Set the current position for a file descriptor
val truncate : string -> int -> unit
-
Truncates the named file to the given size.
val ftruncate : file_descr -> int -> unit
-
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.
val stat : string -> stats
-
Return the information for the named file.
val lstat : string -> stats
-
Same as stat, but in case the file is a symbolic link,
return the information for the link itself.
val fstat : file_descr -> stats
-
Return the information for the file associated with the given
descriptor.
Operations on file names
val unlink : string -> unit
-
Removes the named file
val rename : string -> string -> unit
-
rename old new changes the name of a file from old to new.
val link : string -> string -> unit
-
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.
val chmod : string -> file_perm -> unit
-
Change the permissions of the named file.
val fchmod : file_descr -> file_perm -> unit
-
Change the permissions of an opened file.
val chown : string -> int -> int -> unit
-
Change the owner uid and owner gid of the named file.
val fchown : file_descr -> int -> int -> unit
-
Change the owner uid and owner gid of an opened file.
val umask : int -> int
-
Set the process creation mask, and return the previous mask.
val access : string -> access_permission list -> unit
-
Check that the process has the given permissions over the named
file. Raise Unix_error otherwise.
Operations on file descriptors
val dup : file_descr -> file_descr
-
Return a new file descriptor referencing the same file as
the given descriptor.
val dup2 : file_descr -> file_descr -> unit
-
dup2 fd1 fd2 duplicates fd1 to fd2, closing fd2 if already
opened.
val set_nonblock : file_descr -> unit
val clear_nonblock : file_descr -> unit
-
Set or clear the ``non-blocking'' flag on the given descriptor.
When the non-blocking flag is set, reading on a descriptor
on which there is temporarily no data available raises the
EAGAIN or EWOULDBLOCK error instead of blocking;
writing on a descriptor on which there is temporarily no room
for writing also raises EAGAIN or EWOULDBLOCK.
val set_close_on_exec : file_descr -> unit
val clear_close_on_exec : file_descr -> unit
-
Set or clear the ``close-on-exec'' flag on the given descriptor.
A descriptor with the close-on-exec flag is automatically
closed when the current process starts another program with
one of the exec functions.
Directories
val mkdir : string -> file_perm -> unit
-
Create a directory with the given permissions.
val rmdir : string -> unit
-
Remove an empty directory.
val chdir : string -> unit
-
Change the process working directory.
val getcwd : unit -> string
-
Return the name of the current working directory.
type dir_handle
-
The type of descriptors over opened directories.
val opendir : string -> dir_handle
-
Open a descriptor on a directory
val readdir : dir_handle -> string
-
Return the next entry in a directory.
Raise End_of_file when the end of the directory has been
reached.
val rewinddir : dir_handle -> unit
-
Reposition the descriptor to the beginning of the directory
val closedir : dir_handle -> unit
-
Close a directory descriptor.
Pipes and redirections
val pipe : unit -> file_descr * file_descr
-
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 entrance to the pipe.
val mkfifo : string -> file_perm -> unit
-
Create a named pipe with the given permissions.
High-level process and redirection management
val create_process :
string -> string array -> file_descr -> file_descr -> file_descr -> int
-
create_process prog args new_stdin new_stdout new_stderr
forks a new process that executes the program
in file prog, with arguments args. The pid of the new
process is returned immediately; the new process executes
concurrently with the current process.
The standard input and outputs of the new process are connected
to the descriptors new_stdin, new_stdout and new_stderr.
Passing e.g. stdout for new_stdout prevents the redirection
and causes the new process to have the same standard output
as the current process.
The executable file prog is searched in the path.
The new process has the same environment as the current process.
All file descriptors of the current process are closed in the
new process, except those redirected to standard input and
outputs.
val create_process_env :
string -> string array -> string array ->
file_descr -> file_descr -> file_descr -> int
-
create_process_env prog args env new_stdin new_stdout new_stderr
works as create_process, except that the extra argument
env specifies the environment passed to the program.
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
val symlink : string -> string -> unit
-
symlink source dest creates the file dest as a symbolic link
to the file source.
val readlink : string -> string
-
Read the contents of a link.
Special files
val ioctl_int : file_descr -> int -> int -> 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.
val ioctl_ptr : file_descr -> int -> string -> int
-
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.
Polling
val select :
file_descr list -> file_descr list -> file_descr list -> float ->
file_descr list * file_descr list * file_descr list
-
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.
val lockf : file_descr -> lock_command -> int -> unit
-
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
val kill : int -> int -> unit
-
kill pid sig sends signal number sig to the process
with id pid.
val pause : unit -> unit
-
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.
val time : unit -> int
-
Return the current time since 00:00:00 GMT, Jan. 1, 1970,
in seconds.
val gettimeofday : unit -> float
-
Same as time, but with resolution better than 1 second.
val gmtime : int -> tm
-
Convert a time in seconds, as returned by time, into a date and
a time. Assumes Greenwich meridian time zone.
val localtime : int -> tm
-
Convert a time in seconds, as returned by time, into a date and
a time. Assumes the local time zone.
val mktime : tm -> int * tm
-
Convert a date and time, specified by the tm argument, into
a time in seconds, as returned by time. Also return a normalized
copy of the given tm record, with the tm_wday and tm_yday
recomputed from the other fields.
val alarm : int -> int
-
Schedule a SIGALRM signals after the given number of seconds.
val sleep : int -> unit
-
Stop execution for the given number of seconds.
val times : unit -> process_times =
"unix_times_bytecode" "unix_times_native"
-
Return the execution times of the process.
val utimes : string -> int -> int -> unit
-
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.
type interval_timer =
ITIMER_REAL
| ITIMER_VIRTUAL
| ITIMER_PROF
-
The three kinds of interval timers.
ITIMER_REAL decrements in real time, and sends the signal
SIGALRM when expired.
ITIMER_VIRTUAL decrements in process virtual time, and sends
SIGVTALRM when expired.
ITIMER_PROF (for profiling) decrements both when the process
is running and when the system is running on behalf of the
process; it sends SIGPROF when expired.
type interval_timer_status =
{ it_interval: float; (* Period *)
it_value: float } (* Current value of the timer *)
-
The type describing the status of an interval timer
val getitimer: interval_timer -> interval_timer_status
-
Return the current status of the given interval timer.
val setitimer:
interval_timer -> interval_timer_status -> interval_timer_status
-
setitimer t s sets the interval timer t and returns
its previous status. The s argument is interpreted as follows:
s.it_value, if nonzero, is the time to the next timer expiration;
s.it_interval, if nonzero, specifies a value to
be used in reloading it_value when the timer expires.
Setting s.it_value to zero disable the timer.
Setting s.it_interval to zero causes the timer to be disabled
after its next expiration.
User id, group id
val getuid : unit -> int
-
Return the user id of the user executing the process.
val geteuid : unit -> int
-
Return the effective user id under which the process runs.
val setuid : int -> unit
-
Set the real user id and effective user id for the process.
val getgid : unit -> int
-
Return the group id of the user executing the process.
val getegid : unit -> int
-
Return the effective group id under which the process runs.
val setgid : int -> unit
-
Set the real group id and effective group id for the process.
val getgroups : unit -> int array
-
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.
val getlogin : unit -> string
-
Return the login name of the user executing the process.
val getpwnam : string -> passwd_entry
-
Find an entry in passwd with the given name, or raise
Not_found.
val getgrnam : string -> group_entry
-
Find an entry in group with the given name, or raise
Not_found.
val getpwuid : int -> passwd_entry
-
Find an entry in passwd with the given user id, or raise
Not_found.
val getgrgid : int -> group_entry
-
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.
val inet_addr_of_string : string -> inet_addr
val string_of_inet_addr : inet_addr -> string
-
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.
val inet_addr_any : inet_addr
-
A special Internet address, for use only with bind, representing
all the Internet addresses that the host machine possesses.
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.
val socket : socket_domain -> socket_type -> int -> file_descr
-
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.
val socketpair :
socket_domain -> socket_type -> int -> file_descr * file_descr
-
Create a pair of unnamed sockets, connected together.
val accept : file_descr -> file_descr * sockaddr
-
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.
val bind : file_descr -> sockaddr -> unit
-
Bind a socket to an address.
val connect : file_descr -> sockaddr -> unit
-
Connect a socket to an address.
val listen : file_descr -> int -> unit
-
Set up a socket for receiving connection requests. The integer
argument is the maximal number of pending requests.
type shutdown_command =
SHUTDOWN_RECEIVE (* Close for receiving *)
| SHUTDOWN_SEND (* Close for sending *)
| SHUTDOWN_ALL (* Close both *)
-
The type of commands for shutdown.
val shutdown : file_descr -> shutdown_command -> unit
-
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).
val getsockname : file_descr -> sockaddr
-
Return the address of the given socket.
val getpeername : file_descr -> sockaddr
-
Return the address of the host connected to the given socket.
type msg_flag =
MSG_OOB
| MSG_DONTROUTE
| MSG_PEEK
-
The flags for recv, recvfrom, send and sendto.
val recv : file_descr -> string -> int -> int -> msg_flag list -> int
val recvfrom :
file_descr -> string -> int -> int -> msg_flag list -> int * sockaddr
-
Receive data from an unconnected socket.
val send : file_descr -> string -> int -> int -> msg_flag list -> int
val sendto :
file_descr -> string -> int -> int -> msg_flag list -> sockaddr -> int
-
Send data over an unconnected socket.
type socket_option =
SO_DEBUG (* Record debugging information *)
| SO_BROADCAST (* Permit sending of broadcast messages *)
| SO_REUSEADDR (* Allow reuse of local addresses for bind *)
| SO_KEEPALIVE (* Keep connection active *)
| SO_DONTROUTE (* Bypass the standard routing algorithms *)
| SO_OOBINLINE (* Leave out-of-band data in line *)
-
The socket options settable with setsockopt.
val getsockopt : file_descr -> socket_option -> bool
-
Return the current status of an option in the given socket.
val setsockopt : file_descr -> socket_option -> bool -> unit
-
Set or clear an option in the given 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.
val gethostname : unit -> string
-
Return the name of the local host.
val gethostbyname : string -> host_entry
-
Find an entry in hosts with the given name, or raise
Not_found.
val gethostbyaddr : inet_addr -> host_entry
-
Find an entry in hosts with the given address, or raise
Not_found.
val getprotobyname : string -> protocol_entry
-
Find an entry in protocols with the given name, or raise
Not_found.
val getprotobynumber : int -> protocol_entry
-
Find an entry in protocols with the given protocol number,
or raise Not_found.
val getservbyname : string -> string -> service_entry
-
Find an entry in services with the given name, or raise
Not_found.
val getservbyport : int -> string -> service_entry
-
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. *)
-
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). *)
}
val tcgetattr: file_descr -> terminal_io
-
Return the status of the terminal referred to by the given
file descriptor.
type setattr_when = TCSANOW | TCSADRAIN | TCSAFLUSH
val tcsetattr: file_descr -> setattr_when -> terminal_io -> unit
-
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.
val tcsendbreak: file_descr -> int -> unit
-
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).
val tcdrain: file_descr -> unit
-
Waits until all output written on the given file descriptor
has been transmitted.
type flush_queue = TCIFLUSH | TCOFLUSH | TCIOFLUSH
val tcflush: file_descr -> flush_queue -> unit
-
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
val tcflow: file_descr -> flow_action -> unit
-
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.
val setsid : unit -> int
-
Put the calling process in a new session and detach it from
its controlling terminal.
- Windows:
-
Below is a list of the functions that are not implemented, or only
partially implemented, under Windows. 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 |
lstat, fstat | not implemented |
link, symlink, readlink | not implemented (no links under
Windows) |
chmod, 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 |
ioctl_int, ioctl_ptr | not implemented (no ioctl in Windows) |
select | not implemented; use threads instead |
lockf | not implemented |
kill, pause | not implemented (no inter-process signals in Windows) |
gettimeofday, 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 domain PF_UNIX is not supported;
PF_INET is fully supported |
establish_server | not implemented; use threads |
terminal functions (tc*) | not implemented |