Module BatUnix

The type of error codes. Errors defined in the POSIX standard and additional errors from UNIX98 and BSD. All other errors are mapped to EUNKNOWNERR.

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.

Return a string describing the given error code.

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.

Return the process environment, as an array of strings with the format ``variable=value''.

Return the process environment, as an array of strings with the format ``variable=value''. Unlike environment, this function returns a populated array even if the process has special privileges. See the documentation for unsafe_getenv for more details.

• since 2.8.0 and OCaml 4.06.0

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

• raises Not_found

  if the variable is unbound. (This function is identical to Sys.getenv.)

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

Unlike getenv, this function returns the value even if the process has special privileges. It is considered unsafe because the programmer of a setuid or setgid program must be careful to avoid using maliciously crafted environment variables in the search path for executables, the locations for temporary files or logs, and the like.

• raises Not_found

  if the variable is unbound.

• since 2.8.0 and 4.06.0

Unix.putenv name value sets the value associated to a variable in the process environment. name is the name of the environment variable, and value its new associated value.

The termination status of a process. See module Sys for the definitions of the standard signal numbers. Note that they are not the numbers used by the OS.

Flags for Unix.waitpid.

execv prog args execute the program in file prog, with the arguments args, and the current process environment. These execv* functions never return: on success, the current program is replaced by the new one;

• raises Unix.Unix_error

  on failure.

Same as Unix.execv, except that the third argument provides the environment to the program executed.

Same as Unix.execv, except that the program is searched in the path.

Same as Unix.execve, except that the program is searched in the path.

Fork a new process. The returned integer is 0 for the child process, the pid of the child process for the parent process.

Wait until one of the children processes die, and return its pid and termination status.

Same as Unix.wait, but waits for the child 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.

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.

(stat, output) = run_and_read cmd run the command cmd (via Unix.system) then return its exit status stat and output string output as read from its standard output (which was redirected to a temporary file).

• since 2.4

Terminate the calling process immediately, returning the given status code to the operating system: usually 0 to indicate no errors, and a small positive integer to indicate failure. Unlike Stdlib.exit, Unix._exit performs no finalization whatsoever: functions registered with Stdlib.at_exit are not called, input/output channels are not flushed, and the C run-time system is not finalized either.

The typical use of Unix._exit is after a Unix.fork operation, when the child process runs into a fatal error and must exit. In this case, it is preferable to not perform any finalization action in the child process, as these actions could interfere with similar actions performed by the parent process. For example, output channels should not be flushed by the child process, as the parent process may flush them again later, resulting in duplicate output.

• since 3.3.0 and 4.12.0

Return the pid of the process.

Return the pid of the parent process.

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.

The abstract type of file descriptors.

File descriptor for standard input.

File descriptor for standard output.

File descriptor for standard error.

The type of file access rights, e.g. 0o640 is read and write for user, read for group, none for others

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.

Close a file descriptor.

Flush file buffers to disk.

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.

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. write repeats the writing operation until all characters have been written or an error occurs.

Same as write, but attempts to write only once. Thus, if an error occurs, single_write guarantees that no data has been written.

Same as write, but take the data from a string instead of a byte sequence.

• since 2.3.0

Same as single_write, but take the data from a string instead of a byte sequence.

• since 2.3.0

Create an input reading from the given descriptor. The input is initially in binary mode; use set_binary_mode_in ic false if text mode is desired.

• parameter autoclose

  If true (default value), close the input automatically once there is no more content to read. Otherwise, the input will be closed according to the usual rules of module BatIO. Barring very specific needs (e.g. using file descriptors as locks), you probably want autoclose to be true.

• parameter cleanup

  If true, close the underlying file descriptor when the input is closed. If false or unspecified, do nothing, in which case you will need to close the underlying file descriptor yourself to ensure proper cleanup.

Create an output writing on the given descriptor. The output is initially in binary mode; use set_binary_mode_out oc false if text mode is desired.

• parameter cleanup

  If true, close the underlying file descriptor when the output is closed. If false or unspecified, do nothing, in which case you will need to close the underlying file descriptor yourself to ensure proper cleanup.

Return the descriptor corresponding to an input.

Not all inputs have file descriptors. This function works only for inputs which have been created using module Unix.

• raises Invalid_argument

  if this input channel doesn't have a file descriptor

Return the descriptor corresponding to an output.

Not all inputs have file descriptors. This function works only for inputs which have been created from module Unix.

• raises Invalid_argument

  if this input channel doesn't have a file descriptor

Positioning modes for Unix.lseek.

Set the current position for a file descriptor

Truncates the named file to the given size.

Truncates the file corresponding to the given descriptor to the given size.

The information returned by the Unix.stat calls.

Return the information for the named file.

Same as Unix.stat, but in case the file is a symbolic link, return the information for the link itself.

Return the information for the file associated with the given descriptor.

Return true if the given file descriptor refers to a terminal or console window, false otherwise.

File operations on large files. This sub-module provides 64-bit variants of the functions Unix.lseek (for positioning a file descriptor), Unix.truncate and Unix.ftruncate (for changing the size of a file), and Unix.stat, Unix.lstat and Unix.fstat (for obtaining information on files). These alternate functions represent positions and sizes by 64-bit integers (type int64) instead of regular integers (type int), thus allowing operating on files whose sizes are greater than max_int.

Memory mapping of a file as a big array. map_file fd kind layout shared dims returns a big array of kind kind, layout layout, and dimensions as specified in dims. The data contained in this big array are the contents of the file referred to by the file descriptor fd (as opened previously with Unix.openfile, for example). The optional pos parameter is the byte offset in the file of the data being mapped; it defaults to 0 (map from the beginning of the file).

If shared is true, all modifications performed on the array are reflected in the file. This requires that fd be opened with write permissions. If shared is false, modifications performed on the array are done in memory only, using copy-on-write of the modified pages; the underlying file is not affected.

Genarray.map_file is much more efficient than reading the whole file in a big array, modifying that big array, and writing it afterwards.

To adjust automatically the dimensions of the big array to the actual size of the file, the major dimension (that is, the first dimension for an array with C layout, and the last dimension for an array with Fortran layout) can be given as -1. Genarray.map_file then determines the major dimension from the size of the file. The file must contain an integral number of sub-arrays as determined by the non-major dimensions, otherwise Failure is raised.

If all dimensions of the big array are given, the file size is matched against the size of the big array. If the file is larger than the big array, only the initial portion of the file is mapped to the big array. If the file is smaller than the big array, the file is automatically grown to the size of the big array. This requires write permissions on fd.

Array accesses are bounds-checked, but the bounds are determined by the initial call to map_file. Therefore, you should make sure no other process modifies the mapped file while you're accessing it, or a SIGBUS signal may be raised. This happens, for instance, if the file is shrunk.

Invalid_argument or Failure may be raised in cases where argument validation fails.

• since 2.8.0 and OCaml 4.06.0

Removes the named file

rename old new changes the name of a file from old to new.

link ?follow source dest creates a hard link named dest to the file named source.

• parameter follow

  indicates whether a source symlink is followed or a hardlink to source itself will be created. On Unix systems this is done using the linkat(2) function. If ?follow is not provided, then the link(2) function is used whose behaviour is OS-dependent, but more widely available.

• parameter follow

  is only available since 2.10.0 and OCaml 4.08.

• raises ENOSYS

  On Unix if ~follow:_ is requested, but linkat is unavailable.

• raises ENOSYS

  On Windows if ~follow:false is requested.

Flags for the Unix.access call.

Change the permissions of the named file.

Change the permissions of an opened file.

Change the owner uid and owner gid of the named file.

Change the owner uid and owner gid of an opened file.

Set the process's file mode creation mask, and return the previous mask.

Check that the process has the given permissions over the named file.

• raises Unix_error

  otherwise.

Return a new file descriptor referencing the same file as the given descriptor.

dup2 fd1 fd2 duplicates fd1 to fd2, closing fd2 if already opened.

Set 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 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.

Clear the ``non-blocking'' flag on the given descriptor. See Unix.set_nonblock.

Set 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.

Clear the ``close-on-exec'' flag on the given descriptor. See Unix.set_close_on_exec.

Create a directory with the given permissions.

Remove an empty directory.

Change the process working directory.

Return the name of the current working directory.

Change the process root directory.

The type of descriptors over opened directories.

Open a descriptor on a directory

Return the next entry in a directory.

• raises End_of_file

  when the end of the directory has been reached.

Reposition the descriptor to the beginning of the directory

Close a directory descriptor.

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.

Create a named pipe with the given permissions.

High-level pipe and process management. This function runs the given command in parallel with the program. The standard output of the command is redirected to a pipe, which can be read via the returned input. The command is interpreted by the shell /bin/sh (cf. system).

• parameter autoclose

  If true (default value), close the input automatically once there is no more content to read. Otherwise, the input will be closed according to the usual rules of module BatIO. Barring very specific needs (e.g. using file descriptors as locks), you probably want autoclose to be true.

• parameter cleanup

  If true or unspecified, close the process when the input is closed. If false, do nothing, in which case you will need to close the process yourself to ensure proper cleanup.

Same as Unix.open_process_in, but redirect the standard input of the command to a pipe. Data written to the returned output is sent to the standard input of the command.

Warning writes on outputs are buffered, hence be careful to call Pervasives.flush at the right times to ensure correct synchronization.

• parameter cleanup

  If true or unspecified, close the process when the output is closed. If false, do nothing, in which case you will need to close the process yourself to ensure proper cleanup.

Same as Unix.open_process_out, but redirects both the standard input and standard output of the command to pipes connected to the two returned input/output. The returned input is connected to the output of the command, and the returned output to the input of the command.

• parameter autoclose

  If true (default value), close the input automatically once there is no more content to read. Otherwise, the input will be closed according to the usual rules of module BatIO. Barring very specific needs (e.g. using file descriptors as locks), you probably want autoclose to be true.

• parameter cleanup

  If true or unspecified, close the process when either the output or the output is closed. If false, do nothing, in which case you will need to close the process yourself to ensure proper cleanup.

Similar to Unix.open_process, but the second argument specifies the environment passed to the command. The result is a triple of input/output connected respectively to the standard output, standard input, and standard error of the command.

• parameter autoclose

  If true (default value), close the input automatically once there is no more content to read. Otherwise, the input will be closed according to the usual rules of module BatIO. Barring very specific needs (e.g. using file descriptors as locks), you probably want autoclose to be true.

• parameter cleanup

  If true or unspecified, close the process when either the output or the output is closed. If false, do nothing, in which case you will need to close the process yourself to ensure proper cleanup.

High-level pipe and process management. The first argument specifies the command to run, and the second argument specifies the argument array passed to the command. This function runs the command in parallel with the program. The standard output of the command is redirected to a pipe, which can be read via the returned input channel.

• since 2.10.0 and OCaml 4.08.0

Same as Unix.open_process_args_in, but redirect the standard input of the command to a pipe. Data written to the returned output channel is sent to the standard input of the command. Warning: writes on output channels are buffered, hence be careful to call Stdlib.flush at the right times to ensure correct synchronization.

• since 2.10.0 and OCaml 4.08.0

Same as Unix.open_process_args_out, but redirects both the standard input and standard output of the command to pipes connected to the two returned channels. The input channel is connected to the output of the command, and the output channel to the input of the command.

• since 2.10.0 and OCaml 4.08.0

Similar to Unix.open_process_args, but the third argument specifies the environment passed to the command. The result is a triple of channels connected respectively to the standard output, standard input, and standard error of the command.

• since 2.10.0 and OCaml 4.08.0

Return the pid of a process opened via Unix.open_process_in or Unix.open_process_args_in.

• since 2.10.0 and OCaml 4.08.0

Return the pid of a process opened via Unix.open_process_out or Unix.open_process_args_out.

• since 2.10.0 and OCaml 4.08.0

Return the pid of a process opened via Unix.open_process or Unix.open_process_args.

• since 2.10.0 and OCaml 4.08.0

Return the pid of a process opened via Unix.open_process_full or Unix.open_process_args_full.

• since 2.10.0 and OCaml 4.08.0

Close input opened by Unix.open_process_in, wait for the associated command to terminate, and return its termination status.

• raises Unix_error(EBADF,

  "close_process_in", "") if the argument is not an input opened by Unix.open_process_in.

Close output opened by Unix.open_process_out, wait for the associated command to terminate, and return its termination status.

• raises Unix_error(EBADF,

  "close_process_out", "") if the argument is not an output opened by Unix.open_process_out.

Close input/output opened by Unix.open_process, wait for the associated command to terminate, and return its termination status.

• raises Unix_error(EBADF,

  "close_process", "") if the argument is not pair of input/output opened by Unix.open_process.

Close i/o opened by Unix.open_process_full, wait for the associated command to terminate, and return its termination status.

• raises Unix_error(EBADF,

  "close_process_full", "") if the argument is not a triple of input/output opened by Unix.open_process_full.

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.

create_process_env prog args env new_stdin new_stdout new_stderr works as Unix.create_process, except that the extra argument env specifies the environment passed to the program.

symlink ?to_dir source dest creates the file dest as a symbolic link to the file source. On Windows, ~to_dir indicates if the symbolic link points to a directory or a file; if omitted, symlink examines source using stat and picks appropriately, if source does not exist then false is assumed (for this reason, it is recommended that the ~to_dir parameter be specified in new code). On Unix, ~to_dir ignored.

Windows symbolic links are available in Windows Vista onwards. There are some important differences between Windows symlinks and their POSIX counterparts.

Windows symbolic links come in two flavours: directory and regular, which designate whether the symbolic link points to a directory or a file. The type must be correct - a directory symlink which actually points to a file cannot be selected with chdir and a file symlink which actually points to a directory cannot be read or written (note that Cygwin's emulation layer ignores this distinction).

When symbolic links are created to existing targets, this distinction doesn't matter and symlink will automatically create the correct kind of symbolic link. The distinction matters when a symbolic link is created to a non-existent target.

The other caveat is that by default symbolic links are a privileged operation. Administrators will always need to be running elevated (or with UAC disabled) and by default normal user accounts need to be granted the SeCreateSymbolicLinkPrivilege via Local Security Policy (secpol.msc) or via Active Directory.

has_symlink can be used to check that a process is able to create symbolic links.

• since 4.03 the optional argument ?to_dir was added in 4.03

Returns true if the user is able to create symbolic links. On Windows, this indicates that the user not only has the SeCreateSymbolicLinkPrivilege but is also running elevated, if necessary. On other platforms, this is simply indicates that the symlink system call is available.

• since 2.5.0 and OCaml 4.03

Read the contents of a link.

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).

Commands for 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 Unix.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. A write lock prevents any other process from acquiring a read or write lock on the region. A read lock prevents any other process from acquiring a write lock on the region, but lets other processes acquire read locks on it.

The F_LOCK and F_TLOCK commands attempts to put a write lock on the specified region. The F_RLOCK and F_TRLOCK commands attempts to put a read lock on the specified region. If one or several locks put by another process prevent the current process from acquiring the lock, F_LOCK and F_RLOCK block until these locks are removed, while F_TLOCK and F_TRLOCK fail immediately with an exception. The F_ULOCK removes whatever locks the current process has on the specified region. Finally, the F_TEST command tests whether a write lock can be acquired on the specified region, without actually putting a lock. It returns immediately if successful, or fails otherwise.

with_locked_file ~kind filename f puts a lock (using lockf) on the whole file named filename, calls f with the file descriptor, and returns its result after the file is unlocked. The file is opened with permissions matching kind, and created if it does not exist yet. If f () raises an exception the exception is re-raised after the file is unlocked.

• parameter kind

  specifies whether the lock is read-only or read-write.

kill pid sig sends signal number sig to the process with id pid.

sigprocmask cmd sigs changes the set of blocked signals. If cmd is SIG_SETMASK, blocked signals are set to those in the list sigs. If cmd is SIG_BLOCK, the signals in sigs are added to the set of blocked signals. If cmd is SIG_UNBLOCK, the signals in sigs are removed from the set of blocked signals. sigprocmask returns the set of previously blocked signals.

Return the set of blocked signals that are currently pending.

sigsuspend sigs atomically sets the blocked signals to sigs and waits for a non-ignored, non-blocked signal to be delivered. On return, the blocked signals are reset to their initial value.

Wait until a non-ignored, non-blocked signal is delivered.

The execution times (CPU times) of a process.

The type representing wallclock time and calendar date.

Return the current time since 00:00:00 GMT, Jan. 1, 1970, in seconds.

Same as Unix.time, but with resolution better than 1 second.

Convert a time in seconds, as returned by Unix.time, into a date and a time. Assumes UTC (Coordinated Universal Time), also known as GMT.

Convert a time in seconds, as returned by Unix.time, into a date and a time. Assumes the local time zone.

Convert a date and time, specified by the tm argument, into a time in seconds, as returned by Unix.time. The tm_isdst, tm_wday and tm_yday fields of tm are ignored. Also return a normalized copy of the given tm record, with the tm_wday, tm_yday, and tm_isdst fields recomputed from the other fields, and the other fields normalized (so that, e.g., 40 October is changed into 9 November). The tm argument is interpreted in the local time zone.

Schedule a SIGALRM signal after the given number of seconds.

Stop execution for the given number of seconds.

Stop execution for the given number of seconds. Like sleep, but fractions of seconds are supported.

• since 2.5.0

Return the execution times of the process.

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. A time of 0.0 is interpreted as the current time.

The three kinds of interval timers.

The type describing the status of an interval timer

Return the current status of the given interval timer.

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.

Return the user id of the user executing the process.

Return the effective user id under which the process runs.

Set the real user id and effective user id for the process.

Return the group id of the user executing the process.

Return the effective group id under which the process runs.

Set the real group id and effective group id for the process.

Return the list of groups to which the user executing the process belongs.

setgroups groups sets the supplementary group IDs for the calling process. Appropriate privileges are required.

initgroups user group initializes the group access list by reading the group database /etc/group and using all groups of which user is a member. The additional group group is also added to the list.

Structure of entries in the passwd database.

Structure of entries in the groups database.

Return the login name of the user executing the process.

Find an entry in passwd with the given name.

• raises Not_found

  if no such entry can be found.

Find an entry in group with the given name.

• raises Not_found

  if no such entry can be found.

Find an entry in passwd with the given user id.

• raises Not_found

  if no such entry can be found.

Find an entry in group with the given group id.

• raises Not_found

  if no such entry can be found.

The abstract type of Internet addresses.

Conversion from the printable representation of an Internet address to its internal representation. The argument string consists of 4 numbers separated by periods (XXX.YYY.ZZZ.TTT) for IPv4 addresses, and up to 8 numbers separated by colons for IPv6 addresses.

• raises Failure

  when given a string that does not match these formats.

Return the printable representation of the given Internet address. See Unix.inet_addr_of_string for a description of the printable representation.

A special IPv4 address, for use only with bind, representing all the Internet addresses that the host machine possesses.

A special IPv4 address representing the host machine (127.0.0.1).

A special IPv6 address, for use only with bind, representing all the Internet addresses that the host machine possesses.

A special IPv6 address representing the host machine (::1).

Whether the given inet_addr is an IPv6 address.

• since 3.3.0 and 4.12.0

The type of socket domains. Not all platforms support IPv6 sockets (type PF_INET6).

The type of socket kinds, specifying the semantics of communications.

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.

Return the socket domain adequate for the given socket address.

Create a pair of unnamed sockets, connected together.

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.

Bind a socket to an address.

Connect a socket to an address.

Set up a socket for receiving connection requests. The integer argument is the maximal number of pending requests.

The type of commands for 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).

Return the address of the given socket.

Return the address of the host connected to the given socket.

Receive data from a connected socket.

Receive data from an unconnected socket.

Send data over a connected socket.

Same as send, but take the data from a string instead of a byte sequence.

• since 2.3.0

Send data over an unconnected socket.

Same as sendto, but take the data from a string instead of a byte sequence.

• since 2.3.0

The socket options that can be consulted with Unix.getsockopt and modified with Unix.setsockopt. These options have a boolean (true/false) value.

The socket options that can be consulted with Unix.getsockopt_int and modified with Unix.setsockopt_int. These options have an integer value.

The socket options that can be consulted with Unix.getsockopt_optint and modified with Unix.setsockopt_optint. These options have a value of type int option, with None meaning ``disabled''.

The socket options that can be consulted with Unix.getsockopt_float and modified with Unix.setsockopt_float. These options have a floating-point value representing a time in seconds. The value 0 means infinite timeout.

Return the current status of a boolean-valued option in the given socket.

Set or clear a boolean-valued option in the given socket.

Same as Unix.getsockopt for an integer-valued socket option.

Same as Unix.setsockopt for an integer-valued socket option.

Same as Unix.getsockopt for a socket option whose value is an int option.

Same as Unix.setsockopt for a socket option whose value is an int option.

Same as Unix.getsockopt for a socket option whose value is a floating-point number.

Same as Unix.setsockopt for a socket option whose value is a floating-point number.

Return the error condition associated with the given socket, and clear it.

Connect to a server at the given address. Return a pair of input/output connected to the server. The connection is closed whenever either the input or the output is closed.

Remember to call Pervasives.flush on the output at the right times to ensure correct synchronization.

• parameter autoclose

  If true (default value), close the input automatically once there is no more content to read. Otherwise, the input will be closed according to the usual rules of module BatIO. Barring very specific needs (e.g. using file descriptors as locks), you probably want autoclose to be true.

``Shut down'' a connection established with Unix.open_connection; that is, transmit an end-of-file condition to the server reading on the other side of the connection.

• deprecated

  Connections do not require a special function anymore. Use regular function BatIO.close_in for closing connections.

Establish a server on the given address.

establish_server f addr establishes a server on address addr. For each connection on this address, function f is called with two buffered channels connected to the client. A new process is created for each connection. The function Unix.establish_server never returns normally.

• parameter autoclose

  If true (default value), inputs passed to f close the input automatically once there is no more content to read. Otherwise, the input will be closed according to the usual rules of module BatIO. Barring very specific needs (e.g. using file descriptors as locks), you probably want autoclose to be true.

• parameter cleanup

  If true or unspecified, close the connection when the input or the output is closed or garbage-collected. If false, do nothing, in which case you will need to shutdown the connection using shutdown_connection to ensure proper cleanup.

Structure of entries in the hosts database.

Structure of entries in the protocols database.

Structure of entries in the services database.

Return the name of the local host.

Find an entry in hosts with the given name.

• raises Not_found

  if no such entry can be found.

Find an entry in hosts with the given address.

• raises Not_found

  if no such entry can be found.

Find an entry in protocols with the given name

• raises Not_found

  if no such entry can be found.

Find an entry in protocols with the given protocol number.

• raises Not_found

  if no such entry can be found.

Find an entry in services with the given name.

• raises Not_found

  if no such entry can be found.

Find an entry in services with the given service number.

• raises Not_found

  if no such entry can be found.

Address information returned by Unix.getaddrinfo.

Options to Unix.getaddrinfo.

getaddrinfo host service opts returns a list of Unix.addr_info records describing socket parameters and addresses suitable for communicating with the given host and service. The empty list is returned if the host or service names are unknown, or the constraints expressed in opts cannot be satisfied.

host is either a host name or the string representation of an IP address. host can be given as the empty string; in this case, the ``any'' address or the ``loopback'' address are used, depending whether opts contains AI_PASSIVE. service is either a service name or the string representation of a port number. service can be given as the empty string; in this case, the port field of the returned addresses is set to 0. opts is a possibly empty list of options that allows the caller to force a particular socket domain (e.g. IPv6 only or IPv4 only) or a particular socket type (e.g. TCP only or UDP only).

Host and service information returned by Unix.getnameinfo.

Options to Unix.getnameinfo.

getnameinfo addr opts returns the host name and service name corresponding to the socket address addr. opts is a possibly empty list of options that governs how these names are obtained.

• raises Not_found

  if an error occurs.

Return the status of the terminal referred to by the given file descriptor.

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.

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).

Waits until all output written on the given file descriptor has been transmitted.

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.

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.

Put the calling process in a new session and detach it from its controlling terminal.

is_directory filename returns true if filename refers to a directory (or symlink of a directory)

restart_on_EINTR f x invokes f on x repetedly until the function returns a value or raises another exception than EINTR.

A lock used to synchronize internal operations.

By default, this is BatConcurrent.nolock. However, if you're using a version of Batteries compiled in threaded mode, this uses BatMutex. If you're attempting to use Batteries with another concurrency model, set the lock appropriately.

• deprecated

  use input_of_descr

• deprecated

  use output_of_descr.

• deprecated

  use descr_of_input.

• deprecated

  use descr_of_output.