nidas::util::SerialPort Class Reference

#include <SerialPort.h>

Public Member Functions
	SerialPort ()
	SerialPort (const SerialPort &)
	Copy constructor.
	SerialPort (const std::string &name)
	Constructor, given a device name.
	SerialPort (const std::string &name, int fd)
	For serial port that is already open (stdin for example).
virtual	~SerialPort ()
	close the file descriptor if is is open.
Termios &	termios ()
	Writable reference to the SerialPort's Termios.
const Termios &	getTermios () const
	Readonly reference to Termios.
void	applyTermios ()
	Apply the Termios settings to an opened serial port.
const std::string &	getName () const
	Get device name of the SerialPort.
void	setName (const std::string &val)
	Set device name of the SerialPort.
virtual int	open (int mode=O_RDONLY)
	open the serial port.
void	close ()
	close the file descriptor.
int	getFd () const
int	getModemStatus ()
	Get the current state of the modem bits.
void	setModemStatus (int val)
	Set the current state of the modem bits.
void	clearModemBits (int val)
	Clear the indicated modem bits.
void	setModemBits (int val)
	Set the indicated modem bits.
bool	getCarrierDetect ()
void	setBlocking (bool val)
bool	getBlocking ()
void	drain ()
	Do a tcdrain() system call on the device.
void	flushInput ()
	Do a tcflush() system call on the device.
void	flushOutput ()
	Do a tcflush() system call on the device.
void	flushBoth ()
int	timeoutOrEOF () const
virtual int	readUntil (char *buf, int len, char term)
	Read bytes until either the term character is read, or len-1 number of characters have been read.
virtual int	readLine (char *buf, int len)
	Do a readUntil with a newline terminator.
virtual int	read (char *buf, int len)
virtual char	readchar ()
	Do a buffered read and return character read.
virtual int	write (const void *buf, int len)

Static Public Member Functions
static std::string	modemFlagsToString (int modem)
static int	createPtyLink (const std::string &linkname)
	Static utility that creates a pseudo-terminal, returning the file descriptor of the master side and creating a symbolic link with the given name to the slave side.
static void	createLinkToPty (const std::string &linkname, int fd)
	Create a symbolic link to ptsname(fd).
static int	createPty (bool hup)
	Create a pseudo-terminal and return the file descriptor.
static bool	waitForOpen (int fd, int timeout)
	Wait up to timeout seconds for pts to be opened.

Private Types
enum	state { OK , TIMEOUT_OR_EOF }

Private Member Functions
SerialPort &	operator= (const SerialPort &)
	No assignment.

Private Attributes
Termios	_termios
int	_fd
std::string	_name
enum nidas::util::SerialPort::state	_state
char *	_savep
char *	_savebuf
int	_savelen
int	_savealloc
bool	_blocking

Member Enumeration Documentation

state

enum nidas::util::SerialPort::state

private

Enumerator
OK
TIMEOUT_OR_EOF

Constructor & Destructor Documentation

SerialPort() [1/4]

SerialPort::SerialPort

(

)

SerialPort() [2/4]

SerialPort::SerialPort

(

const SerialPort &

x

)

Copy constructor.

The attributes of the port are copied, but if the original is opened, the copy will not be opened.

SerialPort() [3/4]

SerialPort::SerialPort

(

const std::string &

name

)

Constructor, given a device name.

The device is NOT opened, mainly just to avoid throwing an exception in the constructor. Perhaps that should be changed.

SerialPort() [4/4]

SerialPort::SerialPort	(	const std::string &	name,
		int	fd )

For serial port that is already open (stdin for example).

References getBlocking().

~SerialPort()

SerialPort::~SerialPort ( )

virtual

close the file descriptor if is is open.

References _savebuf, and close().

Member Function Documentation

applyTermios()

void SerialPort::applyTermios

(

)

Apply the Termios settings to an opened serial port.

References _fd, _name, _termios, and nidas::util::Termios::apply().

clearModemBits()

void SerialPort::clearModemBits

(

int

val

)

Clear the indicated modem bits.

References _fd, and _name.

close()

void SerialPort::close

(

)

close the file descriptor.

References _fd, close(), getName(), and ILOG.

Referenced by close(), createPty(), Garmin::run(), GPS_SetClock::run(), and ~SerialPort().

createLinkToPty()

void SerialPort::createLinkToPty ( const std::string & linkname, int fd )

static

Create a symbolic link to ptsname(fd).

fd must be a pty, such as returned by createPty().

References fd.

Referenced by createPtyLink().

createPty()

int SerialPort::createPty ( bool hup )

static

Create a pseudo-terminal and return the file descriptor.

This is called by createPtyLink(), but it can also be called separately if the caller wants to pass hup as true to set the HUP condition on the slave side before creating the link.

References close(), DLOG, fd, and open().

Referenced by createPtyLink().

createPtyLink()

int SerialPort::createPtyLink ( const std::string & linkname )

static

Static utility that creates a pseudo-terminal, returning the file descriptor of the master side and creating a symbolic link with the given name to the slave side.

It is a convenient wrapper for this code:

int fd = createPty(false);
createLinkToPty(linkname, fd);

Parameters

linkname

Name of symbolic link to be created that links to the slave side of the pseudo-terminal. If a symbolic link already exists with that name it will be removed and re-created. If linkname already exists and it isn't a symbolic link, an error will be returned.

Returns

The file descriptor of the master side of the pseudo-terminal.

Note: the symbolic link should be deleted when the file descriptor to the master pseudo-terminal is closed. Otherwise, because of the way the system recycles pseudo-terminal devices, the link may at some time point to a different pseudo-terminal, probably created by a different process, like sshd. Opening and reading/writing to the symbolic link would then effect the other process, if the open was permitted.

References createLinkToPty(), createPty(), and fd.

drain()

void SerialPort::drain

(

)

Do a tcdrain() system call on the device.

According to the tcdrain man page, it "waits until all output written to the object referred to by fd has been transmitted".

References _fd, and _name.

flushBoth()

void SerialPort::flushBoth

(

)

References _fd, and _name.

flushInput()

void SerialPort::flushInput

(

)

Do a tcflush() system call on the device.

According to the tcflush man page, it "discards data received but not read".

References _fd, and _name.

flushOutput()

void SerialPort::flushOutput

(

)

Do a tcflush() system call on the device.

According to the tcflush man page, it "discards data written to the object referred to by fd but not transmitted".

References _fd, and _name.

getBlocking()

bool SerialPort::getBlocking

(

)

References _blocking, _fd, and _name.

Referenced by SerialPort().

getCarrierDetect()

bool SerialPort::getCarrierDetect

(

)

References getModemStatus().

getFd()

int nidas::util::SerialPort::getFd ( ) const

inline

References _fd.

Referenced by GPS_SetClock::run(), and Csat3Sim::run().

getModemStatus()

int SerialPort::getModemStatus

(

)

Get the current state of the modem bits.

Do "man tty_ioctl" from Linux for more information. These macros are useful for checking/setting the value of of individual bits:

TIOCM_LE        DSR (data set ready/line enable)
TIOCM_DTR       DTR (data terminal ready)
TIOCM_RTS       RTS (request to send)
TIOCM_ST        Secondary TXD (transmit)
TIOCM_SR        Secondary RXD (receive)
TIOCM_CTS       CTS (clear to send)
TIOCM_CAR       DCD (data carrier detect)
TIOCM_CD         see TIOCM_CAR
TIOCM_RNG       RNG (ring)
TIOCM_RI         see TIOCM_RNG
TIOCM_DSR       DSR (data set ready)

References _fd, and _name.

Referenced by getCarrierDetect().

getName()

const std::string & nidas::util::SerialPort::getName ( ) const

inline

Get device name of the SerialPort.

References _name.

Referenced by close(), open(), Garmin::readMessage(), GPS_SetClock::run(), and Csat3Sim::run().

getTermios()

const Termios & nidas::util::SerialPort::getTermios ( ) const

inline

Readonly reference to Termios.

References _termios.

modemFlagsToString()

string SerialPort::modemFlagsToString ( int modem )

static

open()

int SerialPort::open ( int mode = O_RDONLY )

virtual

open the serial port.

The current Termios settings are also applied to the port.

References _blocking, _fd, _name, _termios, nidas::util::Termios::apply(), getName(), ILOG, open(), and setBlocking().

Referenced by createPty(), open(), Garmin::run(), and GPS_SetClock::run().

operator=()

SerialPort & nidas::util::SerialPort::operator= ( const SerialPort & )

private

No assignment.

read()

int SerialPort::read ( char * buf, int len )

virtual

References _fd, _name, _state, len, OK, read(), and TIMEOUT_OR_EOF.

Referenced by read(), readchar(), readUntil(), and Csat3Sim::run().

readchar()

char SerialPort::readchar ( )

virtual

Do a buffered read and return character read.

If '\0' is read, then do a check of timeoutOrEOF() to see if the basic read returned 0.

References _savealloc, _savebuf, _savelen, _savep, and read().

Referenced by SensorSimulator::readPrompts().

readLine()

int SerialPort::readLine ( char * buf, int len )

virtual

Do a readUntil with a newline terminator.

References len, and readUntil().

Referenced by GPS_SetClock::run().

readUntil()

int SerialPort::readUntil ( char * buf, int len, char term )

virtual

Read bytes until either the term character is read, or len-1 number of characters have been read.

buf will be null terminated.

References _savealloc, _savebuf, _savelen, _savep, len, and read().

Referenced by readLine(), and Garmin::readMessage().

setBlocking()

void SerialPort::setBlocking

(

bool

val

)

References _blocking, _fd, and _name.

Referenced by open().

setModemBits()

void SerialPort::setModemBits

(

int

val

)

Set the indicated modem bits.

References _fd, and _name.

setModemStatus()

void SerialPort::setModemStatus

(

int

val

)

Set the current state of the modem bits.

References _fd, and _name.

setName()

void nidas::util::SerialPort::setName ( const std::string & val )

inline

Set device name of the SerialPort.

References _name.

Referenced by Garmin::run().

termios()

Termios & nidas::util::SerialPort::termios ( )

inline

Writable reference to the SerialPort's Termios.

If the SerialPort is open, the user should call applyTermios() for any modifications to take effect.

References _termios.

Referenced by Garmin::run(), and GPS_SetClock::run().

timeoutOrEOF()

int nidas::util::SerialPort::timeoutOrEOF ( ) const

inline

References _state, and TIMEOUT_OR_EOF.

waitForOpen()

bool SerialPort::waitForOpen ( int fd, int timeout )

static

Wait up to timeout seconds for pts to be opened.

Wait up to the timeout for the HUP to be cleared. If the HUP condition was set when the pty was created, then the cleared HUP means the ptsname(fd) device has been opened. Wait forever if timeout is negative. The poll() does not block on the fd, so it is called at 1-second intervals using sleep(), until the timeout expires or the poll returns with the POLLHUP bit cleared.

So here is a typical usage:

int fd = createPty(true);
createLinkToPty(link, fd);
bool opened = waitForOpen(fd, -1);

The existence of the link is a synchronization point, indicating the pty has been created and HUP set, so it's safe to wait for HUP to be cleared to know that it has been opened.

References fd.

write()

int SerialPort::write ( const void * buf, int len )

virtual

References _blocking, _fd, _name, len, and write().

Referenced by Garmin::disableAllMessages(), Garmin::disablePPS(), Garmin::enableAllMessages(), Garmin::enablePPS(), Garmin::readInit(), Csat3Sim::run(), Csat3Sim::sendMessage(), Garmin::setBaudRateOption(), write(), SensorSimulator::writeMessage(), and SensorSimulator::writeMessage().

Member Data Documentation

_blocking

bool nidas::util::SerialPort::_blocking

private

Referenced by getBlocking(), open(), setBlocking(), and write().

_fd

int nidas::util::SerialPort::_fd

private

Referenced by applyTermios(), clearModemBits(), close(), drain(), flushBoth(), flushInput(), flushOutput(), getBlocking(), getFd(), getModemStatus(), open(), read(), setBlocking(), setModemBits(), setModemStatus(), and write().

_name

std::string nidas::util::SerialPort::_name

private

Referenced by applyTermios(), clearModemBits(), drain(), flushBoth(), flushInput(), flushOutput(), getBlocking(), getModemStatus(), getName(), open(), read(), setBlocking(), setModemBits(), setModemStatus(), setName(), and write().

_savealloc

int nidas::util::SerialPort::_savealloc

private

Referenced by readchar(), and readUntil().

_savebuf

char* nidas::util::SerialPort::_savebuf

private

Referenced by readchar(), readUntil(), and ~SerialPort().

_savelen

int nidas::util::SerialPort::_savelen

private

Referenced by readchar(), and readUntil().

_savep

char* nidas::util::SerialPort::_savep

private

Referenced by readchar(), and readUntil().

_state

enum nidas::util::SerialPort::state nidas::util::SerialPort::_state

private

Referenced by read(), and timeoutOrEOF().

_termios

Termios nidas::util::SerialPort::_termios

private

Referenced by applyTermios(), getTermios(), open(), and termios().

---

The documentation for this class was generated from the following files:

• nidas/util/SerialPort.h
• nidas/util/SerialPort.cc