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/*
* Author : Rishi Gupta
*
* This file is part of 'serial communication manager' library.
* Copyright (C) <2014-2016>
*
* This 'serial communication manager' is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by the Free Software
* Foundation, either version 3 of the License, or (at your option) any later version.
*
* The 'serial communication manager' is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
* A PARTICULAR PURPOSE. See the GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with 'serial communication manager'. If not, see Provides APIs to create and destroy virtual serial ports using the tty2comKm null modem emulation
* driver provided by this library. It follows the protocol as defined by tty2comKm driver.
*
* @author Rishi Gupta
*/
public final class SerialComNullModem {
/** Bit mask bit specifying that the given pin should be left unconnected.
* Constant with value 0x0000. */
public static final int SCM_CON_NONE = 0x0000;
/** Bit mask bit specifying that the given pin should be connected to CTS pin of other end.
* Constant with value 0x0001.
*/
public static final int SCM_CON_CTS = 0x0001;
/** Bit mask bit specifying that the given pin should be connected to DCD pin of other end.
* Constant with value 0x0002.
*/
public static final int SCM_CON_DCD = 0x0002;
/** Bit mask bit specifying that the given pin should be connected to DSR pin of other end.
* Constant with value 0x0004.
*/
public static final int SCM_CON_DSR = 0x0004;
/** Bit mask bit specifying that the given pin should be connected to RI pin of other end.
* Constant with value 0x0008.
*/
public static final int SCM_CON_RI = 0x0008;
/** Bit mask bit specifying that a framing error should be emulated.
* Constant with value 0x0010. */
public static final int ERR_FRAME = 0x0010;
/** Bit mask bit specifying that a parity error should be emulated.
* Constant with value 0x0020. */
public static final int ERR_PARITY = 0x0020;
/** Bit mask bit specifying that a overrun error should be emulated.
* Constant with value 0x0040. */
public static final int ERR_OVERRUN = 0x0040;
private final int osType;
private FileOutputStream linuxVadaptOut;
private FileInputStream linuxVadaptIn;
private final Object lock = new Object();
// creation of devices, removal of devices and modification to these maps is synchronized.
private final TreeMap loopBackDevList;
private final TreeMap nullModemDevList;
/**
* Create an instance of SerialComNullModem with given details.
*
* @param osType operating system this library is running on.
* @throws IOException if the operating system and tty2comKm driver specific files are
* not found at the time this method is called.
*/
public SerialComNullModem(int osType) throws IOException {
this.osType = osType;
if(osType == SerialComManager.OS_LINUX) {
try {
linuxVadaptOut = new FileOutputStream(new File("/proc/scmtty_vadaptkm"));
} catch(Exception e) {
throw e;
}
try {
linuxVadaptIn = new FileInputStream(new File("/proc/scmtty_vadaptkm"));
} catch(IOException e) {
try {
linuxVadaptOut.close();
} catch (IOException e1) {
throw e1;
}
throw e;
}
}
loopBackDevList = new TreeMap();
nullModemDevList = new TreeMap();
}
/**
* Creates a standard loop back connected virtual serial port device. If deviceIndex is -1, the
* next available index will be used by driver. If deviceIndex is a valid number, the given index
* will be used to create device node.
*
* For example; createStandardLoopBackDevice(2) will create /dev/tty2com2 device node in Linux or
* will throw exception if that number is already in use. Similarly createStandardLoopBackDevice(-1)
* will create /dev/tty2comXX where XX is the next free number managed by the driver internally.
*
* @param deviceIndex -1 or valid device number (0 <= deviceIndex =< 65535).
* @return Created virtual loop back device's node on success.
* @throws IOException if virtual loop back device can not be created,
* IllegalArgumentException if deviceIndex is invalid.
*/
public String createStandardLoopBackDevice(int deviceIndex) throws IOException {
byte[] cmd = null;
String lbdev = null;
if(osType == SerialComManager.OS_LINUX) {
if(deviceIndex == -1) {
cmd = "genlb#xxxxx#xxxxx#7-8,x,x,x#4-1,6,x,x#x-x,x,x,x#x-x,x,x,x#y#y".getBytes();
}else {
if((deviceIndex < 0) || (deviceIndex > 65535)) {
throw new IllegalArgumentException("deviceIndex should be -1 <= deviceIndex =< 65535 !");
}
String cmdd = "genlb#".concat(String.format("%05d", deviceIndex));
cmdd = cmdd.concat("#xxxxx#7-8,x,x,x#4-1,6,x,x#x-x,x,x,x#x-x,x,x,x#y#y");
cmd = cmdd.getBytes();
}
synchronized(lock) {
linuxVadaptOut.write(cmd);
lbdev = getLastLoopBackDeviceNode();
if(deviceIndex == -1) {
int idx = Integer.parseInt(lbdev.substring(12), 10);
loopBackDevList.put(idx, lbdev);
}else {
loopBackDevList.put(deviceIndex, lbdev);
}
}
}
return lbdev;
}
/**
* Creates a standard null modem connected virtual serial port device pair. If deviceIndex is -1, the
* next available index will be used by driver. If deviceIndex is a valid number, the given index
* will be used to create device nodes.
*
* For example; createStandardNullModemDevices(2, 3) will create /dev/tty2com2 and /dev/tty2com3 device
* nodes in Linux or will throw exception if any of the given number is already in use. Similarly
* createStandardNullModemDevices(-1, -1) will create /dev/tty2comXX and /dev/tty2comYY where XX/YY are the
* next free numbers managed by the driver internally.
*
* @param deviceIndex1 -1 or valid device number (0 <= deviceIndex1 =< 65535).
* @param deviceIndex2 -1 or valid device number (0 <= deviceIndex1 =< 65535).
* @return Created virtual null modem pair device's node on success.
* @throws IOException if virtual null modem device pair can not be created,
* IllegalArgumentException if deviceIndex1/2 is invalid.
*/
public String[] createStandardNullModemPair(int deviceIndex1, int deviceIndex2) throws IOException {
byte[] cmd = null;
String[] nmdevs = null;
if(osType == SerialComManager.OS_LINUX) {
if(deviceIndex1 == -1) {
if(deviceIndex2 == -1) {
cmd = "gennm#xxxxx#xxxxx#7-8,x,x,x#4-1,6,x,x#7-8,x,x,x#4-1,6,x,x#y#y".getBytes();
}else {
if((deviceIndex2 < 0) || (deviceIndex2 > 65535)) {
throw new IllegalArgumentException("deviceIndex2 should be -1 <= deviceIndex2 =< 65535 !");
}
String cmdd = "gennm#xxxxx#".concat(String.format("%05d", deviceIndex2));
cmdd = cmdd.concat("#7-8,x,x,x#4-1,6,x,x#7-8,x,x,x#4-1,6,x,x#y#y");
}
}else {
if(deviceIndex2 == -1) {
String cmdd = "gennm#".concat(String.format("%05d", deviceIndex1));
cmdd = cmdd.concat("#xxxxx#7-8,x,x,x#4-1,6,x,x#7-8,x,x,x#4-1,6,x,x#y#y");
cmd = cmdd.getBytes();
}else {
if((deviceIndex1 < 0) || (deviceIndex1 > 65535)) {
throw new IllegalArgumentException("deviceIndex1 should be -1 <= deviceIndex1 =< 65535 !");
}
String cmdd = "gennm#".concat(String.format("%05d", deviceIndex1));
cmdd = cmdd.concat("#");
cmdd = cmdd.concat(String.format("%05d", deviceIndex2));
cmdd = cmdd.concat("#7-8,x,x,x#4-1,6,x,x#7-8,x,x,x#4-1,6,x,x#y#y");
cmd = cmdd.getBytes();
}
}
synchronized(lock) {
linuxVadaptOut.write(cmd);
nmdevs = getLastNullModemDevicePairNodes();
int idx = Integer.parseInt(nmdevs[0].substring(12), 10);
StringBuilder sb = new StringBuilder();
sb.append(nmdevs[0]);
sb.append(" <=> ");
sb.append(nmdevs[1]);
nullModemDevList.put(idx, sb.toString());
}
}
return nmdevs;
}
/**
* Creates a virtual loop back device with given pin mappings.
*
* To connect RTS pin to CTS pin use rtsMap = SerialComNullModem.SCM_CON_CTS. A pin can be
* connected to one or more pins using bit mask. For example to connect RTS pin to CTS and DSR use
* rtsMap = SerialComNullModem.SCM_CON_CTS | SerialComNullModem.SCM_CON_DSR.
*
* @param deviceIndex -1 or valid device number (0 <= deviceIndex =< 65535).
* @param rtsMap Bit mask of SerialComNullModem.SCM_CON_XXX constants as per the desired pin mappings
* or 0 if RTS pin should be left unconnected.
* @param dtrMap Bit mask of SerialComNullModem.SCM_CON_XXX constants as per the desired pin mappings
* or 0 if DTR pin should be left unconnected.
* @return Created virtual loop back device's node on success.
* @throws IOException if the operation can not be completed successfully,
* IllegalArgumentException if invalid deviceIndex is supplied.
*/
public String createCustomLoopBackDevice(int deviceIndex, int rtsMap, int dtrMap) throws IOException {
String lbdev = null;
StringBuilder sb = new StringBuilder();
if(osType == SerialComManager.OS_LINUX) {
sb.append("genlb#");
if(deviceIndex < 0) {
if(deviceIndex != -1) {
throw new IllegalArgumentException("Argument deviceIndex should be -1 <= deviceIndex =< 65535 !");
}
sb.append("xxxxx#xxxxx#7-");
}else {
if(deviceIndex > 65535) {
throw new IllegalArgumentException("Argument deviceIndex should be -1 <= deviceIndex =< 65535 !");
}
sb.append(String.format("%05d", deviceIndex));
sb.append("#xxxxx#7-");
}
if(rtsMap == SCM_CON_NONE) {
sb.append("x,x,x,x#4-");
}else {
if((rtsMap & SCM_CON_CTS) == SCM_CON_CTS) {
sb.append(8);
}else {
sb.append("x");
}
sb.append(",");
if((rtsMap & SCM_CON_DCD) == SCM_CON_DCD) {
sb.append(1);
}else {
sb.append("x");
}
sb.append(",");
if((rtsMap & SCM_CON_DSR) == SCM_CON_DSR) {
sb.append(6);
}else {
sb.append("x");
}
sb.append(",");
if((rtsMap & SCM_CON_RI) == SCM_CON_RI) {
sb.append(9);
}else {
sb.append("x");
}
sb.append("#4-");
}
if(dtrMap == SCM_CON_NONE) {
sb.append("x,x,x,x");
}else {
if((dtrMap & SCM_CON_CTS) == SCM_CON_CTS) {
sb.append(8);
}else {
sb.append("x");
}
sb.append(",");
if((dtrMap & SCM_CON_DCD) == SCM_CON_DCD) {
sb.append(1);
}else {
sb.append("x");
}
sb.append(",");
if((dtrMap & SCM_CON_DSR) == SCM_CON_DSR) {
sb.append(6);
}else {
sb.append("x");
}
sb.append(",");
if((dtrMap & SCM_CON_RI) == SCM_CON_RI) {
sb.append(9);
}else {
sb.append("x");
}
}
sb.append("#x-x,x,x,x#x-x,x,x,x#y#y");
synchronized(lock) {
linuxVadaptOut.write(sb.toString().getBytes());
lbdev = getLastLoopBackDeviceNode();
if(deviceIndex == -1) {
int idx = Integer.parseInt(lbdev.substring(12), 10);
loopBackDevList.put(idx, lbdev);
}else {
loopBackDevList.put(deviceIndex, lbdev);
}
}
}
return lbdev;
}
/**
* Creates a null modem device pair with given pin mappings.
*
* @param idx1 index of 1st virtual serial port to be created.
* @param rtsMap1 pin mappings definition (define how RTS pin of idx1 device should be connected to pins of idx2 device).
* @param dtrMap1 pin mappings definition (define how DTR pin of idx1 device should be connected to pins of idx2 device).
* @param idx2 index of 2nd virtual serial port to be created.
* @param rtsMap2 pin mappings definition (define how RTS pin of idx2 device should be connected to pins of idx1 device).
* @param dtrMap2 pin mappings definition (define how DTR pin of idx2 device should be connected to pins of idx1 device).
* @return Created virtual null modem pair device's node on success.
* @throws IOException if the null modem device node pair can not be created,
* IllegalArgumentException if invalid idx1/2 is supplied.
*/
public String[] createCustomNullModemPair(int idx1, int rtsMap1, int dtrMap1, int idx2, int rtsMap2, int dtrMap2) throws IOException {
String[] nmdevs = null;
StringBuilder sb = new StringBuilder();
if(osType == SerialComManager.OS_LINUX) {
sb.append("gennm#");
if(idx1 < 0) {
if(idx1 != -1) {
throw new IllegalArgumentException("Argument idx1 should be -1 <= idx1 =< 65535 !");
}
sb.append("xxxxx");
}else {
if(idx1 > 65535) {
throw new IllegalArgumentException("Argument idx1 should be -1 <= idx1 =< 65535 !");
}
sb.append(String.format("%05d", idx1));
}
sb.append("#");
if(idx2 < 0) {
if(idx2 != -1) {
throw new IllegalArgumentException("Argument idx2 should be -1 <= idx2 =< 65535 !");
}
sb.append("xxxxx");
}else {
if(idx2 > 65535) {
throw new IllegalArgumentException("Argument idx2 should be -1 <= idx2 =< 65535 !");
}
sb.append(String.format("%05d", idx2));
}
sb.append("#7-");
if(rtsMap1 == SCM_CON_NONE) {
sb.append("x,x,x,x#4-");
}else {
if((rtsMap1 & SCM_CON_CTS) == SCM_CON_CTS) {
sb.append(8);
}else {
sb.append("x");
}
sb.append(",");
if((rtsMap1 & SCM_CON_DCD) == SCM_CON_DCD) {
sb.append(1);
}else {
sb.append("x");
}
sb.append(",");
if((rtsMap1 & SCM_CON_DSR) == SCM_CON_DSR) {
sb.append(6);
}else {
sb.append("x");
}
sb.append(",");
if((rtsMap1 & SCM_CON_RI) == SCM_CON_RI) {
sb.append(9);
}else {
sb.append("x");
}
sb.append("#4-");
}
if(dtrMap1 == SCM_CON_NONE) {
sb.append("x,x,x,x#7-");
}else {
if((dtrMap1 & SCM_CON_CTS) == SCM_CON_CTS) {
sb.append(8);
}else {
sb.append("x");
}
sb.append(",");
if((dtrMap1 & SCM_CON_DCD) == SCM_CON_DCD) {
sb.append(1);
}else {
sb.append("x");
}
sb.append(",");
if((dtrMap1 & SCM_CON_DSR) == SCM_CON_DSR) {
sb.append(6);
}else {
sb.append("x");
}
sb.append(",");
if((dtrMap1 & SCM_CON_RI) == SCM_CON_RI) {
sb.append(9);
}else {
sb.append("x");
}
sb.append("#7-");
}
if(rtsMap2 == SCM_CON_NONE) {
sb.append("x,x,x,x#4-");
}else {
if((rtsMap2 & SCM_CON_CTS) == SCM_CON_CTS) {
sb.append(8);
}else {
sb.append("x");
}
sb.append(",");
if((rtsMap2 & SCM_CON_DCD) == SCM_CON_DCD) {
sb.append(1);
}else {
sb.append("x");
}
sb.append(",");
if((rtsMap2 & SCM_CON_DSR) == SCM_CON_DSR) {
sb.append(6);
}else {
sb.append("x");
}
sb.append(",");
if((rtsMap2 & SCM_CON_RI) == SCM_CON_RI) {
sb.append(9);
}else {
sb.append("x");
}
sb.append("#4-");
}
if(dtrMap2 == SCM_CON_NONE) {
sb.append("x,x,x,x#y#y");
}else {
if((dtrMap2 & SCM_CON_CTS) == SCM_CON_CTS) {
sb.append(8);
}else {
sb.append("x");
}
sb.append(",");
if((dtrMap2 & SCM_CON_DCD) == SCM_CON_DCD) {
sb.append(1);
}else {
sb.append("x");
}
sb.append(",");
if((dtrMap2 & SCM_CON_DSR) == SCM_CON_DSR) {
sb.append(6);
}else {
sb.append("x");
}
sb.append(",");
if((dtrMap2 & SCM_CON_RI) == SCM_CON_RI) {
sb.append(9);
}else {
sb.append("x");
}
sb.append("#y#y");
}
synchronized(lock) {
linuxVadaptOut.write(sb.toString().getBytes());
nmdevs = getLastNullModemDevicePairNodes();
int idx = Integer.parseInt(nmdevs[0].substring(12), 10);
StringBuilder sb1 = new StringBuilder();
sb1.append(nmdevs[0]);
sb1.append(" <=> ");
sb1.append(nmdevs[1]);
nullModemDevList.put(idx, sb1.toString());
}
}
return nmdevs;
}
/**
* Removes all virtual serial devices created by tty2comKm driver.
*
* @return true on success.
* @throws IOException if the operation can not be completed due to some reason.
*/
public boolean destroyAllVirtualDevices() throws IOException {
if(osType == SerialComManager.OS_LINUX) {
synchronized(lock) {
linuxVadaptOut.write("del#xxxxx#xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx".getBytes());
loopBackDevList.clear();
nullModemDevList.clear();
}
}
return true;
}
/**
* Removes the virtual loop back device created using tty2comKm driver.
*
* @param deviceNode virtual serial port to be destroyed.
* @return true on success.
* @throws IOException if the given device can not be deleted due to some reason,
* IllegalArgumentException if invalid deviceNode is supplied or deviceNode is null.
*/
public boolean destroyVirtualLoopBackDevice(final String deviceNode) throws IOException {
if((deviceNode == null) || (deviceNode.length() == 0)) {
throw new IllegalArgumentException("The deviceNode can not be null or 0 length !");
}
if(osType == SerialComManager.OS_LINUX) {
int nodeNum = Integer.parseInt(deviceNode.substring(12), 10);
synchronized(lock) {
if(loopBackDevList.containsKey(nodeNum)) {
String cmd = "del#".concat(String.format("%05d", nodeNum));
cmd = cmd.concat("#xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx");
linuxVadaptOut.write(cmd.getBytes());
loopBackDevList.remove(nodeNum);
return true;
}
}
throw new IllegalArgumentException("Given device node is not found in our records !");
}
return false;
}
/**
* Removes the virtual null modem device pair created using tty2comKm driver. The devNode1 must be
* 1st device node as returned by createStandardNullModemPair() or createCustomNullModemPair() methods.
*
* @param devNode1 one of the device node of null modem pair to be destroyed.
* @param devNode2 one of the device node of null modem pair to be destroyed.
* @return true on success.
* @throws IOException if the given device can not be deleted due to some reason,
* IllegalArgumentException if invalid deviceNode is supplied or devNode1/2 is null.
*/
public boolean destroyVirtualNullModemPair(final String devNode1, final String devNode2) throws IOException {
if((devNode1 == null) || (devNode1.length() == 0) || (devNode2 == null) || (devNode2.length() == 0)) {
throw new IllegalArgumentException("The devNode1/2 can not be null or 0 length string !");
}
if(devNode1.equals(devNode2)) {
throw new IllegalArgumentException("The devNode1 can not be equal to devNode2 !");
}
if(osType == SerialComManager.OS_LINUX) {
int idx = Integer.parseInt(devNode1.substring(12), 10);
String pair = nullModemDevList.get(idx);
if(pair == null) {
throw new IllegalArgumentException("Given device nodes are not found in our records !");
}
if(pair.contains(devNode2)) {
String cmd = "del#".concat(String.format("%05d", idx));
cmd = cmd.concat("#xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx");
linuxVadaptOut.write(cmd.getBytes());
nullModemDevList.remove(idx);
return true;
}
throw new IllegalArgumentException("Given devNode1 and devNode2 seems not to be a null modem pair !");
}
return false;
}
/**
* Returns the device node of last created loop back device.
*
* @return Device node on success otherwise null.
* @throws IOException if the operation can not be completed for some reason.
*/
public String getLastLoopBackDeviceNode() throws IOException {
byte data[] = new byte[64];
byte tmp[] = new byte[5];
if(osType == SerialComManager.OS_LINUX) {
linuxVadaptIn.read(data); // 00002#00009-00016
for(int q=0; q<5; q++) {
tmp[q] = data[q];
}
int nodeNum = Integer.parseInt(new String(tmp), 10);
StringBuilder sb = new StringBuilder();
sb.append("/dev/tty2com");
sb.append(nodeNum);
return sb.toString();
}
return null;
}
/**
* Returns the device nodes of last created null modem pair.
*
* @return Device nodes of null modem pair on success otherwise null.
* @throws IOException if the operation can not be completed for some reason.
*/
public String[] getLastNullModemDevicePairNodes() throws IOException {
byte data[] = new byte[64];
byte tmp1[] = new byte[5];
byte tmp2[] = new byte[5];
if(osType == SerialComManager.OS_LINUX) {
linuxVadaptIn.read(data);
for(int q=0; q<5; q++) {
tmp1[q] = data[q + 6];
}
for(int q=0; q<5; q++) {
tmp2[q] = data[q + 12];
}
int nodeNum1 = Integer.parseInt(new String(tmp1), 10);
int nodeNum2 = Integer.parseInt(new String(tmp2), 10);
StringBuilder sb = new StringBuilder();
sb.append("/dev/tty2com");
sb.append(nodeNum1);
String[] nodes = new String[2];
nodes[0] = sb.toString();
sb.delete(0, sb.length());
sb.append("/dev/tty2com");
sb.append(nodeNum2);
nodes[1] = sb.toString();
return nodes;
}
return null;
}
/**
* Returns list of virtual loop back devices created by tty2comKm driver and currently present in system.
*
* @return list of virtual loop back devices created by tty2comKm driver and currently present in system or
* null if no loop back device is created.
*/
public String[] listLoopBackDevices() {
int x = 0;
String[] list = null;
synchronized(lock) {
int msize = loopBackDevList.size();
if(msize == 0) {
return null;
}
list = new String[msize];
for (Map.Entry entry : loopBackDevList.entrySet()) {
list[x] = entry.getValue();
x++;
}
}
return list;
}
/**
* Returns list of virtual null modem device pairs created by tty2comKm driver and currently present
* in system.
*
* @return list of virtual null modem devices created by tty2comKm driver and currently present in system
* or null if no null modem pair is created.
*/
public String[] listNullModemDevicePairs() {
int x = 0;
String[] list = null;
synchronized(lock) {
int msize = nullModemDevList.size();
if(msize == 0) {
return null;
}
list = new String[msize];
for (Map.Entry entry : nullModemDevList.entrySet()) {
list[x] = entry.getValue();
x++;
}
}
return list;
}
/**
* Emulate the given line error (frame, parity or overrun) on given device.
*
* @param devNode virtual serial port which will receive this error event.
* @param error one of the constants SerialComNullModem.ERR_XXX.
* @return true if the given error has been emulated on given virtual serial port otherwise
* false.
* @throws IOException if the operating system specific file is not found, writing to it fails
* or operation can not be completed due to some reason.
*/
public boolean emulateLineError(final String devNode, int error) throws IOException {
if((devNode == null) || (devNode.length() == 0)) {
throw new IllegalArgumentException("The devNode can not be null or 0 length !");
}
if(osType == SerialComManager.OS_LINUX) {
// /sys/devices/virtual/tty/tty2com0/scmvtty_errevt/evt
StringBuilder sb = new StringBuilder();
sb.append("/sys/devices/virtual/tty/");
sb.append(devNode.substring(12));
sb.append("/scmvtty_errevt/evt");
try (FileOutputStream fout = new FileOutputStream(sb.toString())) {
if((error & ERR_FRAME) == ERR_FRAME) {
fout.write("1".getBytes());
}else if((error & ERR_PARITY) == ERR_PARITY) {
fout.write("2".getBytes());
}else if((error & ERR_OVERRUN) == ERR_OVERRUN) {
fout.write("3".getBytes());
}else {
return false;
}
} catch (IOException e) {
throw e;
}
}
return true;
}
/**
* Emulate line ringing event on given device node.
*
* @param devNode device node which will observe ringing conditions.
* @param state true if ringing event should be asserted or false for de-assertion.
* @return true on success.
* @throws IOException if the operating system specific file is not found, writing to it fails
* or operation can not be completed due to some reason.
*/
public boolean emulateLineRingingEvent(final String devNode, boolean state) throws IOException {
if((devNode == null) || (devNode.length() == 0)) {
throw new IllegalArgumentException("The devNode can not be null or 0 length !");
}
if(osType == SerialComManager.OS_LINUX) {
// /sys/devices/virtual/tty/tty2com0/scmvtty_errevt/evt
StringBuilder sb = new StringBuilder();
sb.append("/sys/devices/virtual/tty/");
sb.append(devNode.substring(12));
sb.append("/scmvtty_errevt/evt");
try (FileOutputStream fout = new FileOutputStream(sb.toString())) {
if(state == true) {
fout.write("4".getBytes());
}else {
fout.write("5".getBytes());
}
} catch (IOException e) {
throw e;
}
}
return true;
}
/**
* Releases operating system specific resources acquired to carry out virtual device related
* operations. Applications must call this method when this class is no longer required.
*
* @return true on success.
* @throws IOException if the resources can not be released.
*/
public boolean releaseResources() throws IOException {
if(osType == SerialComManager.OS_LINUX) {
try {
linuxVadaptOut.close();
} catch (IOException e) {
try {
linuxVadaptIn.close();
} catch (IOException e1) {
throw e1;
}
throw e;
}
try {
linuxVadaptIn.close();
} catch (IOException e) {
throw e;
}
}
return true;
}
}
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