+/**
+ * Read bytes from the specified serial port, blocking until complete.
+ *
+ * @warning If your program runs on Unix, defines its own signal handlers, and
+ * needs to abort blocking reads when these are called, then you
+ * should not use this function. It repeats system calls that return
+ * with EINTR. To be able to abort a read from a signal handler, you
+ * should implement your own blocking read using sp_nonblocking_read()
+ * together with a blocking method that makes sense for your program.
+ * E.g. you can obtain the file descriptor for an open port using
+ * sp_get_port_handle() and use this to call select() or pselect(),
+ * with appropriate arrangements to return if a signal is received.
+ *
+ * @param port Pointer to port structure.
+ * @param buf Buffer in which to store the bytes read.
+ * @param count Requested number of bytes to read.
+ * @param timeout Timeout in milliseconds, or zero to wait indefinitely.
+ *
+ * @return The number of bytes read on success, or a negative error code. If
+ * the number of bytes returned is less than that requested, the
+ * timeout was reached before the requested number of bytes was
+ * available. If timeout is zero, the function will always return
+ * either the requested number of bytes or a negative error code.
+ *
+ * @since 0.1.0
+ */
+enum sp_return sp_blocking_read(struct sp_port *port, void *buf, size_t count, unsigned int timeout);
+
+/**
+ * Read bytes from the specified serial port, without blocking.
+ *
+ * @param port Pointer to port structure.
+ * @param buf Buffer in which to store the bytes read.
+ * @param count Maximum number of bytes to read.
+ *
+ * @return The number of bytes read on success, or a negative error code. The
+ * number of bytes returned may be any number from zero to the maximum
+ * that was requested.
+ *
+ * @since 0.1.0
+ */
+enum sp_return sp_nonblocking_read(struct sp_port *port, void *buf, size_t count);
+
+/**
+ * Write bytes to the specified serial port, blocking until complete.
+ *
+ * Note that this function only ensures that the accepted bytes have been
+ * written to the OS; they may be held in driver or hardware buffers and not
+ * yet physically transmitted. To check whether all written bytes have actually
+ * been transmitted, use the sp_output_waiting() function. To wait until all
+ * written bytes have actually been transmitted, use the sp_drain() function.
+ *
+ * @warning If your program runs on Unix, defines its own signal handlers, and
+ * needs to abort blocking writes when these are called, then you
+ * should not use this function. It repeats system calls that return
+ * with EINTR. To be able to abort a write from a signal handler, you
+ * should implement your own blocking write using sp_nonblocking_write()
+ * together with a blocking method that makes sense for your program.
+ * E.g. you can obtain the file descriptor for an open port using
+ * sp_get_port_handle() and use this to call select() or pselect(),
+ * with appropriate arrangements to return if a signal is received.
+ *
+ * @param port Pointer to port structure.
+ * @param buf Buffer containing the bytes to write.
+ * @param count Requested number of bytes to write.
+ * @param timeout Timeout in milliseconds, or zero to wait indefinitely.
+ *
+ * @return The number of bytes written on success, or a negative error code.
+ * If the number of bytes returned is less than that requested, the
+ * timeout was reached before the requested number of bytes was
+ * written. If timeout is zero, the function will always return
+ * either the requested number of bytes or a negative error code. In
+ * the event of an error there is no way to determine how many bytes
+ * were sent before the error occurred.
+ *
+ * @since 0.1.0
+ */
+enum sp_return sp_blocking_write(struct sp_port *port, const void *buf, size_t count, unsigned int timeout);
+
+/**
+ * Write bytes to the specified serial port, without blocking.
+ *
+ * Note that this function only ensures that the accepted bytes have been
+ * written to the OS; they may be held in driver or hardware buffers and not
+ * yet physically transmitted. To check whether all written bytes have actually
+ * been transmitted, use the sp_output_waiting() function. To wait until all
+ * written bytes have actually been transmitted, use the sp_drain() function.
+ *
+ * @param port Pointer to port structure.
+ * @param buf Buffer containing the bytes to write.
+ * @param count Maximum number of bytes to write.
+ *
+ * @return The number of bytes written on success, or a negative error code.
+ * The number of bytes returned may be any number from zero to the
+ * maximum that was requested.
+ *
+ * @since 0.1.0
+ */
+enum sp_return sp_nonblocking_write(struct sp_port *port, const void *buf, size_t count);
+
+/**
+ * Gets the number of bytes waiting in the input buffer.
+ *
+ * @param port Pointer to port structure.
+ *
+ * @return Number of bytes waiting on success, a negative error code otherwise.
+ *
+ * @since 0.1.0
+ */
+enum sp_return sp_input_waiting(struct sp_port *port);
+
+/**
+ * Gets the number of bytes waiting in the output buffer.
+ *
+ * @param port Pointer to port structure.
+ *
+ * @return Number of bytes waiting on success, a negative error code otherwise.
+ *
+ * @since 0.1.0
+ */
+enum sp_return sp_output_waiting(struct sp_port *port);
+
+/**
+ * Flush serial port buffers. Data in the selected buffer(s) is discarded.
+ *
+ * @param port Pointer to port structure.
+ * @param buffers Which buffer(s) to flush.
+ *
+ * @return SP_OK upon success, a negative error code otherwise.
+ *
+ * @since 0.1.0
+ */
+enum sp_return sp_flush(struct sp_port *port, enum sp_buffer buffers);
+
+/**
+ * Wait for buffered data to be transmitted.
+ *
+ * @warning If your program runs on Unix, defines its own signal handlers, and
+ * needs to abort draining the output buffer when when these are
+ * called, then you should not use this function. It repeats system
+ * calls that return with EINTR. To be able to abort a drain from a
+ * signal handler, you would need to implement your own blocking
+ * drain by polling the result of sp_output_waiting().
+ *
+ * @param port Pointer to port structure.
+ *
+ * @return SP_OK upon success, a negative error code otherwise.
+ *
+ * @since 0.1.0
+ */
+enum sp_return sp_drain(struct sp_port *port);
+
+/**
+ * @}
+ *
+ * @defgroup Waiting Waiting
+ *
+ * Waiting for events and timeout handling.
+ *
+ * @{
+ */
+
+/**
+ * Allocate storage for a set of events.
+ *
+ * The user should allocate a variable of type struct sp_event_set *,
+ * then pass a pointer to this variable to receive the result.
+ *
+ * The result should be freed after use by calling sp_free_event_set().
+ *
+ * @return SP_OK upon success, a negative error code otherwise.
+ *
+ * @since 0.1.0
+ */
+enum sp_return sp_new_event_set(struct sp_event_set **result_ptr);
+
+/**
+ * Add events to a struct sp_event_set for a given port.
+ *
+ * The port must first be opened by calling sp_open() using the same port
+ * structure.
+ *
+ * After the port is closed or the port structure freed, the results may
+ * no longer be valid.
+ *
+ * @param event_set Event set to update.
+ * @param port Pointer to port structure.
+ * @param mask Bitmask of events to be waited for.
+ *
+ * @return SP_OK upon success, a negative error code otherwise.
+ *
+ * @since 0.1.0
+ */
+enum sp_return sp_add_port_events(struct sp_event_set *event_set,
+ const struct sp_port *port, enum sp_event mask);
+
+/**
+ * Wait for any of a set of events to occur.
+ *
+ * @param event_set Event set to wait on.
+ * @param timeout Timeout in milliseconds, or zero to wait indefinitely.
+ *
+ * @return SP_OK upon success, a negative error code otherwise.
+ *
+ * @since 0.1.0
+ */
+enum sp_return sp_wait(struct sp_event_set *event_set, unsigned int timeout);
+
+/**
+ * Free a structure allocated by sp_new_event_set().
+ *
+ * @since 0.1.0
+ */
+void sp_free_event_set(struct sp_event_set *event_set);
+
+/**
+ * @}
+ *
+ * @defgroup Signals Signals
+ *
+ * Port signalling operations.
+ *
+ * @{
+ */
+
+/**
+ * Gets the status of the control signals for the specified port.
+ *
+ * The user should allocate a variable of type "enum sp_signal" and pass a
+ * pointer to this variable to receive the result. The result is a bitmask
+ * in which individual signals can be checked by bitwise OR with values of
+ * the sp_signal enum.
+ *
+ * @param port Pointer to port structure.
+ * @param signal_mask Pointer to variable to receive result.
+ *
+ * @return SP_OK upon success, a negative error code otherwise.
+ *
+ * @since 0.1.0
+ */
+enum sp_return sp_get_signals(struct sp_port *port, enum sp_signal *signal_mask);
+
+/**
+ * Put the port transmit line into the break state.
+ *
+ * @param port Pointer to port structure.
+ *
+ * @return SP_OK upon success, a negative error code otherwise.
+ *
+ * @since 0.1.0
+ */
+enum sp_return sp_start_break(struct sp_port *port);
+
+/**
+ * Take the port transmit line out of the break state.
+ *
+ * @param port Pointer to port structure.
+ *
+ * @return SP_OK upon success, a negative error code otherwise.
+ *
+ * @since 0.1.0
+ */
+enum sp_return sp_end_break(struct sp_port *port);
+
+/**
+ * @}
+ *
+ * @defgroup Errors Errors
+ *
+ * Obtaining error information.
+ *
+ * @{
+ */
+
+/**
+ * Get the error code for a failed operation.
+ *
+ * In order to obtain the correct result, this function should be called
+ * straight after the failure, before executing any other system operations.
+ *
+ * @return The system's numeric code for the error that caused the last
+ * operation to fail.
+ *
+ * @since 0.1.0
+ */
+int sp_last_error_code(void);
+
+/**
+ * Get the error message for a failed operation.
+ *
+ * In order to obtain the correct result, this function should be called
+ * straight after the failure, before executing other system operations.
+ *
+ * @return The system's message for the error that caused the last
+ * operation to fail. This string may be allocated by the function,
+ * and should be freed after use by calling sp_free_error_message().
+ *
+ * @since 0.1.0
+ */
+char *sp_last_error_message(void);
+
+/**
+ * Free an error message returned by sp_last_error_message().
+ *
+ * @since 0.1.0
+ */
+void sp_free_error_message(char *message);
+
+/**
+ * Set the handler function for library debugging messages.
+ *
+ * Debugging messages are generated by the library during each operation,
+ * to help in diagnosing problems. The handler will be called for each
+ * message. The handler can be set to NULL to ignore all debug messages.
+ *
+ * The handler function should accept a format string and variable length
+ * argument list, in the same manner as e.g. printf().
+ *
+ * The default handler is sp_default_debug_handler().
+ *
+ * @since 0.1.0
+ */
+void sp_set_debug_handler(void (*handler)(const char *format, ...));
+
+/**
+ * Default handler function for library debugging messages.
+ *
+ * This function prints debug messages to the standard error stream if the
+ * environment variable LIBSERIALPORT_DEBUG is set. Otherwise, they are
+ * ignored.
+ *
+ * @since 0.1.0
+ */
+void sp_default_debug_handler(const char *format, ...);
+
+/** @} */
+
+/**
+ * @defgroup Versions Versions
+ *
+ * Version number querying functions, definitions, and macros.
+ *
+ * This set of API calls returns two different version numbers related
+ * to libserialport. The "package version" is the release version number of the
+ * libserialport tarball in the usual "major.minor.micro" format, e.g. "0.1.0".
+ *
+ * The "library version" is independent of that; it is the libtool version
+ * number in the "current:revision:age" format, e.g. "2:0:0".
+ * See http://www.gnu.org/software/libtool/manual/libtool.html#Libtool-versioning for details.
+ *
+ * Both version numbers (and/or individual components of them) can be
+ * retrieved via the API calls at runtime, and/or they can be checked at
+ * compile/preprocessor time using the respective macros.
+ *
+ * @{
+ */
+
+/*
+ * Package version macros (can be used for conditional compilation).
+ */
+
+/** The libserialport package 'major' version number. */
+#define SP_PACKAGE_VERSION_MAJOR @SP_PACKAGE_VERSION_MAJOR@
+
+/** The libserialport package 'minor' version number. */
+#define SP_PACKAGE_VERSION_MINOR @SP_PACKAGE_VERSION_MINOR@
+
+/** The libserialport package 'micro' version number. */
+#define SP_PACKAGE_VERSION_MICRO @SP_PACKAGE_VERSION_MICRO@
+
+/** The libserialport package version ("major.minor.micro") as string. */
+#define SP_PACKAGE_VERSION_STRING "@SP_PACKAGE_VERSION@"
+
+/*
+ * Library/libtool version macros (can be used for conditional compilation).
+ */
+
+/** The libserialport libtool 'current' version number. */
+#define SP_LIB_VERSION_CURRENT @SP_LIB_VERSION_CURRENT@
+
+/** The libserialport libtool 'revision' version number. */
+#define SP_LIB_VERSION_REVISION @SP_LIB_VERSION_REVISION@
+
+/** The libserialport libtool 'age' version number. */
+#define SP_LIB_VERSION_AGE @SP_LIB_VERSION_AGE@
+
+/** The libserialport libtool version ("current:revision:age") as string. */
+#define SP_LIB_VERSION_STRING "@SP_LIB_VERSION@"
+
+/**
+ * Get the major libserialport package version number.
+ *
+ * @return The major package version number.
+ *
+ * @since 0.1.0
+ */
+int sp_get_major_package_version(void);
+
+/**
+ * Get the minor libserialport package version number.
+ *
+ * @return The minor package version number.
+ *
+ * @since 0.1.0
+ */
+int sp_get_minor_package_version(void);
+
+/**
+ * Get the micro libserialport package version number.
+ *
+ * @return The micro package version number.
+ *
+ * @since 0.1.0
+ */
+int sp_get_micro_package_version(void);
+
+/**
+ * Get the libserialport package version number as a string.
+ *
+ * @return The package version number string. The returned string is
+ * static and thus should NOT be free'd by the caller.
+ *
+ * @since 0.1.0
+ */
+const char *sp_get_package_version_string(void);
+
+/**
+ * Get the "current" part of the libserialport library version number.
+ *
+ * @return The "current" library version number.
+ *
+ * @since 0.1.0
+ */
+int sp_get_current_lib_version(void);
+
+/**
+ * Get the "revision" part of the libserialport library version number.
+ *
+ * @return The "revision" library version number.
+ *
+ * @since 0.1.0
+ */
+int sp_get_revision_lib_version(void);
+
+/**
+ * Get the "age" part of the libserialport library version number.
+ *
+ * @return The "age" library version number.
+ *
+ * @since 0.1.0
+ */
+int sp_get_age_lib_version(void);
+
+/**
+ * Get the libserialport library version number as a string.
+ *
+ * @return The library version number string. The returned string is
+ * static and thus should NOT be free'd by the caller.
+ *
+ * @since 0.1.0
+ */
+const char *sp_get_lib_version_string(void);
+
+/** @} */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif