Ping Class

Properties   Methods   Events   Config Settings   Errors  

The PING class encapsulates Internet Control Message Protocol (ICMP) ECHO functionality, which is used to check whether there is a communications link between two computers.

Syntax

Ping

Remarks

When the PingHost method is called with the Host parameter, or if RemoteHost is assigned an IP address or domain name, the class sends an ICMP ECHO packet to the remote host. The ResponseTime and ResponseSource properties are updated with the time of the roundtrip to the remote host and the address of the host actually sending the response.

The class operates synchronously by default (i.e., waits for a response before returning control to the caller); however, the class may also operate asynchronously (i.e., returns control immediately) by setting Timeout to 0. Please refer to the Timeout property for more information.

Property List

The following is the full list of the properties of the class with short descriptions. Click on the links for further details.

Method List

The following is the full list of the methods of the class with short descriptions. Click on the links for further details.

Event List

The following is the full list of the events fired by the class with short descriptions. Click on the links for further details.

Config Settings

The following is a list of config settings for the class with short descriptions. Click on the links for further details.

Active Property (Ping Class)

This property indicates whether the class is active.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int GetActive();

Unicode (Windows)
BOOL GetActive();

int ipworks_ping_getactive(void* lpObj);

bool GetActive();

Default Value

FALSE

Remarks

This property indicates whether the class is currently active and can send or receive data. Use the Activate and Deactivate methods to control whether the class is active.

The PingHost method will automatically change the value of this property to True.

This property is read-only and not available at design time.

Data Type

Boolean

Idle Property (Ping Class)

The current status of the class.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int GetIdle();

Unicode (Windows)
BOOL GetIdle();

int ipworks_ping_getidle(void* lpObj);

bool GetIdle();

Default Value

TRUE

Remarks

This property will be False if the component is currently busy (communicating or waiting for an answer), and True at all other times.

This property is read-only.

Data Type

Boolean

LocalHost Property (Ping Class)

The name of the local host or user-assigned IP interface through which connections are initiated or accepted.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
char* GetLocalHost();
int SetLocalHost(const char* lpszLocalHost);

Unicode (Windows)
LPWSTR GetLocalHost();
INT SetLocalHost(LPCWSTR lpszLocalHost);

char* ipworks_ping_getlocalhost(void* lpObj);
int ipworks_ping_setlocalhost(void* lpObj, const char* lpszLocalHost);

QString GetLocalHost();
int SetLocalHost(QString qsLocalHost);

Default Value

""

Remarks

This property contains the name of the local host as obtained by the gethostname() system call, or if the user has assigned an IP address, the value of that address.

In multihomed hosts (machines with more than one IP interface) setting LocalHost to the IP address of an interface will make the class initiate connections (or accept in the case of server classs) only through that interface. It is recommended to provide an IP address rather than a hostname when setting this property to ensure the desired interface is used.

If the class is connected, the LocalHost property shows the IP address of the interface through which the connection is made in internet dotted format (aaa.bbb.ccc.ddd). In most cases, this is the address of the local host, except for multihomed hosts (machines with more than one IP interface).

Note: LocalHost is not persistent. You must always set it in code, and never in the property window.

Data Type

String

PacketSize Property (Ping Class)

This property includes the size of the packet to send as the ping request.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int GetPacketSize();
int SetPacketSize(int iPacketSize);

Unicode (Windows)
INT GetPacketSize();
INT SetPacketSize(INT iPacketSize);

int ipworks_ping_getpacketsize(void* lpObj);
int ipworks_ping_setpacketsize(void* lpObj, int iPacketSize);

int GetPacketSize();
int SetPacketSize(int iPacketSize);

Default Value

64

Remarks

This property allows you to control the size of the data packet sent in the PingHost method. The default packet size is 64 bytes, with a minimum of 8 bytes (4 bytes of the ICMP header plus the ECHO identifier). The maximum value is 65520.

Data Type

Integer

RemoteHost Property (Ping Class)

This property includes the address of the RemoteHost. Domain names are resolved to IP addresses.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
char* GetRemoteHost();
int SetRemoteHost(const char* lpszRemoteHost);

Unicode (Windows)
LPWSTR GetRemoteHost();
INT SetRemoteHost(LPCWSTR lpszRemoteHost);

char* ipworks_ping_getremotehost(void* lpObj);
int ipworks_ping_setremotehost(void* lpObj, const char* lpszRemoteHost);

QString GetRemoteHost();
int SetRemoteHost(QString qsRemoteHost);

Default Value

""

Remarks

This property specifies the IP address (IP number in dotted internet format) or the domain name of the remote host.

If this property is set to 255.255.255.255, the class broadcasts data on the local subnet.

If this property is set to a domain name, a DNS request is initiated. Upon successful termination of the request, the property is set to the corresponding address. If the search is not successful, the class fails with an error.

If UseConnection is True, this property must be set before the class is activated (Active is set to True).

Data Type

String

RequestId Property (Ping Class)

This property includes a unique identifier for outgoing packets.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int GetRequestId();

Unicode (Windows)
INT GetRequestId();

int ipworks_ping_getrequestid(void* lpObj);

int GetRequestId();

Default Value

0

Remarks

This property contains a unique identifier for outgoing packets. This property is useful during asynchronous ping operations. The RequestId parameter of the Response event is used to match requests with responses.

The identifier of the outgoing ping packet is provided in this property after the PingHost method returns.

This property is read-only and not available at design time.

Data Type

Integer

ResponseSource Property (Ping Class)

This property includes the source of the last PING response.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
char* GetResponseSource();

Unicode (Windows)
LPWSTR GetResponseSource();

char* ipworks_ping_getresponsesource(void* lpObj);

QString GetResponseSource();

Default Value

""

Remarks

This property contains the address of the host responding to the PING (ICMP ECHO) request. This may or may not be the host used in PingHost.

This property is read-only.

Data Type

String

ResponseStatus Property (Ping Class)

This property includes the status of the last PING response.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
char* GetResponseStatus();

Unicode (Windows)
LPWSTR GetResponseStatus();

char* ipworks_ping_getresponsestatus(void* lpObj);

QString GetResponseStatus();

Default Value

""

Remarks

This property contains the status of the last response. After PingHost has returned, this property will be populated with the status of the response. For responses without error, the value will be OK. In the case of an error, the value will hold a description of the error, such as Network Unreachable or Host Unreachable.

This property is read-only.

Data Type

String

ResponseTime Property (Ping Class)

This property includes the time elapsed between sending the original packet and the remote host reply.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int GetResponseTime();

Unicode (Windows)
INT GetResponseTime();

int ipworks_ping_getresponsetime(void* lpObj);

int GetResponseTime();

Default Value

0

Remarks

This property contains the time elapsed between sending the original packet and the remote host reply. The time value is expressed in milliseconds. The lowest resolution available depends on the resolution of the clock on the host system (normally between 10 ms and 20 ms).

This property is read-only.

Data Type

Integer

Timeout Property (Ping Class)

This property includes the timeout for the class.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int GetTimeout();
int SetTimeout(int iTimeout);

Unicode (Windows)
INT GetTimeout();
INT SetTimeout(INT iTimeout);

int ipworks_ping_gettimeout(void* lpObj);
int ipworks_ping_settimeout(void* lpObj, int iTimeout);

int GetTimeout();
int SetTimeout(int iTimeout);

Default Value

60

Remarks

If the Timeout property is set to 0, all operations return immediately, potentially failing with a WOULDBLOCK error if data cannot be sent immediately.

If Timeout is set to a positive value, data is sent in a blocking manner and the class will wait for the operation to complete before returning control. The class will handle any potential WOULDBLOCK errors internally and automatically retry the operation for a maximum of Timeout seconds.

The class will use DoEvents to enter an efficient wait loop during any potential waiting period, making sure that all system events are processed immediately as they arrive. This ensures that the host application does not freeze and remains responsive.

If Timeout expires, and the operation is not yet complete, the class fails with an error.

Note: By default, all timeouts are inactivity timeouts, that is, the timeout period is extended by Timeout seconds when any amount of data is successfully sent or received.

The default value for the Timeout property is 60 seconds.

Data Type

Integer

TimeToLive Property (Ping Class)

This property includes the time-to-live (TTL) value for the ICMP packets sent by the class.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int GetTimeToLive();
int SetTimeToLive(int iTimeToLive);

Unicode (Windows)
INT GetTimeToLive();
INT SetTimeToLive(INT iTimeToLive);

int ipworks_ping_gettimetolive(void* lpObj);
int ipworks_ping_settimetolive(void* lpObj, int iTimeToLive);

int GetTimeToLive();
int SetTimeToLive(int iTimeToLive);

Default Value

0

Remarks

This method contains the time-to-live (TTL) value for the ICMP packets sent by the class. The TTL field of the ICMP packet is a counter limiting the lifetime of a packet.

Each router (or other module) that handles a packet decrements the TTL field by one or more if it holds the packet for more than one second. Thus, the TTL value is effectively a hop count limit on how far a datagram can propagate through the internet. When the TTL value is reduced to zero (or less), the packet is discarded.

If the value of the property is set to zero, then the default TTL value of the underlying Transmission Control Protocol (TCP)/IP subsystem will be used.

This property is not available at design time.

Data Type

Integer

TypeOfService Property (Ping Class)

This property includes the type of ICMP message sent as a ping request.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int GetTypeOfService();
int SetTypeOfService(int iTypeOfService);

Unicode (Windows)
INT GetTypeOfService();
INT SetTypeOfService(INT iTypeOfService);

int ipworks_ping_gettypeofservice(void* lpObj);
int ipworks_ping_settypeofservice(void* lpObj, int iTypeOfService);

int GetTypeOfService();
int SetTypeOfService(int iTypeOfService);

Default Value

8

Remarks

This property contains the type of the ICMP message sent as a ping request. The default value is 8 (ECHO REQUEST).

This property is not available at design time.

Data Type

Integer

Activate Method (Ping Class)

This method enables sending and receiving data.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int Activate();

Unicode (Windows)
INT Activate();

int ipworks_ping_activate(void* lpObj);

int Activate();

Remarks

This method enables sending and receiving of data.

Note: Calling the PingHost method will automatically activate the class.

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

Config Method (Ping Class)

Sets or retrieves a configuration setting.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
char* Config(const char* lpszConfigurationString);

Unicode (Windows)
LPWSTR Config(LPCWSTR lpszConfigurationString);

char* ipworks_ping_config(void* lpObj, const char* lpszConfigurationString);

QString Config(const QString& qsConfigurationString);

Remarks

Config is a generic method available in every class. It is used to set and retrieve configuration settings for the class.

These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the class, access to these internal properties is provided through the Config method.

To set a configuration setting named PROPERTY, you must call Config("PROPERTY=VALUE"), where VALUE is the value of the setting expressed as a string. For boolean values, use the strings "True", "False", "0", "1", "Yes", or "No" (case does not matter).

To read (query) the value of a configuration setting, you must call Config("PROPERTY"). The value will be returned as a string.

Error Handling (C++)

This method returns a String value; after it returns, call the GetLastErrorCode() method to obtain its result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message.

Deactivate Method (Ping Class)

This method disables sending and receiving data.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int Deactivate();

Unicode (Windows)
INT Deactivate();

int ipworks_ping_deactivate(void* lpObj);

int Deactivate();

Remarks

This method disables sending and receiving data.

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

DoEvents Method (Ping Class)

This method processes events from the internal message queue.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int DoEvents();

Unicode (Windows)
INT DoEvents();

int ipworks_ping_doevents(void* lpObj);

int DoEvents();

Remarks

When DoEvents is called, the class processes any available events. If no events are available, it waits for a preset period of time, and then returns.

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

Interrupt Method (Ping Class)

This method interrupts the current method.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int Interrupt();

Unicode (Windows)
INT Interrupt();

int ipworks_ping_interrupt(void* lpObj);

int Interrupt();

Remarks

If there is no method in progress, Interrupt simply returns, doing nothing.

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

PingHost Method (Ping Class)

This method pings a host.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int PingHost(const char* lpszHost);

Unicode (Windows)
INT PingHost(LPCWSTR lpszHost);

int ipworks_ping_pinghost(void* lpObj, const char* lpszHost);

int PingHost(const QString& qsHost);

Remarks

This method will ping a host. A valid internet domain name or address must be specified in Host, or an error will be returned.

A PING request (ICMP ECHO) is sent to the Host.

Example. Ping a Host:

PingControl.PingHost("MyHostName") ResponseTime = PingControl.ResponseTime

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

Reset Method (Ping Class)

This method will reset the class.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int Reset();

Unicode (Windows)
INT Reset();

int ipworks_ping_reset(void* lpObj);

int Reset();

Remarks

This method will reset the class's properties to their default values.

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

ResolveRemoteHost Method (Ping Class)

This method resolves the hostname in RemoteHost to an IP address.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int ResolveRemoteHost();

Unicode (Windows)
INT ResolveRemoteHost();

int ipworks_ping_resolveremotehost(void* lpObj);

int ResolveRemoteHost();

Remarks

This method resolves the hostname specified by RemoteHost to an IP address. The resolved value is available in the RemoteHost property after this method returns.

In most cases, calling this method is not necessary; the class will resolve the hostname automatically when needed. If DelayHostResolution is true, this method may be called to manually resolve RemoteHost, if desired.

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

WakeOnLAN Method (Ping Class)

This method sends a Wake-On-LAN packet.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
int WakeOnLAN(const char* lpszRemoteHost, const char* lpszMACAddress);

Unicode (Windows)
INT WakeOnLAN(LPCWSTR lpszRemoteHost, LPCWSTR lpszMACAddress);

int ipworks_ping_wakeonlan(void* lpObj, const char* lpszRemoteHost, const char* lpszMACAddress);

int WakeOnLAN(const QString& qsRemoteHost, const QString& qsMACAddress);

Remarks

When this method is called, a Wake-On-LAN packet is sent to RemoteHost (which may also be a broadcast address). This has the effect of powering on the machine (if such functionality is supported by the network card on the remote machine).

The physical address of the remote host must be supplied in the MACAddress parameter.

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

Error Event (Ping Class)

Fired when information is available about errors during data delivery.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
virtual int FireError(PingErrorEventParams *e);

typedef struct {
  int ErrorCode;
  const char *Description;
  int reserved;
} PingErrorEventParams;


Unicode (Windows)
virtual INT FireError(PingErrorEventParams *e);

typedef struct {
  INT ErrorCode;
  LPCWSTR Description;
  INT reserved;
} PingErrorEventParams;

#define EID_PING_ERROR 1

virtual INT IPWORKS_CALL FireError(INT &iErrorCode, LPSTR &lpszDescription);

class PingErrorEventParams {
public:
  int ErrorCode();

  const QString &Description();

  int EventRetVal();
  void SetEventRetVal(int iRetVal);
};

// To handle, connect one or more slots to this signal.
void Error(PingErrorEventParams *e);

// Or, subclass Ping and override this emitter function.
virtual int FireError(PingErrorEventParams *e) {...}

Remarks

The Error event is fired in case of exceptional conditions during message processing. Normally the class fails with an error.

The ErrorCode parameter contains an error code, and the Description parameter contains a textual description of the error. For a list of valid error codes and their descriptions, please refer to the Error Codes section.

Response Event (Ping Class)

This event is fired when a response packet is received.

Syntax

• C++
• C
• Qt

ANSI (Cross Platform)
virtual int FireResponse(PingResponseEventParams *e);

typedef struct {
  int RequestId;
  const char *ResponseSource;
  const char *ResponseStatus;
  int ResponseTime;
  int reserved;
} PingResponseEventParams;


Unicode (Windows)
virtual INT FireResponse(PingResponseEventParams *e);

typedef struct {
  INT RequestId;
  LPCWSTR ResponseSource;
  LPCWSTR ResponseStatus;
  INT ResponseTime;
  INT reserved;
} PingResponseEventParams;

#define EID_PING_RESPONSE 2

virtual INT IPWORKS_CALL FireResponse(INT &iRequestId, LPSTR &lpszResponseSource, LPSTR &lpszResponseStatus, INT &iResponseTime);

class PingResponseEventParams {
public:
  int RequestId();

  const QString &ResponseSource();

  const QString &ResponseStatus();

  int ResponseTime();

  int EventRetVal();
  void SetEventRetVal(int iRetVal);
};

// To handle, connect one or more slots to this signal.
void Response(PingResponseEventParams *e);

// Or, subclass Ping and override this emitter function.
virtual int FireResponse(PingResponseEventParams *e) {...}

Remarks

The RequestId parameter is used along with the RequestId property to match requests with responses.

ResponseStatus is set to OK for normal operation, or it contains an error string, such as Network unreachable or Host unreachable.

Config Settings (Ping Class)

Ping Config Settings

ICMP Config Settings

Socket Config Settings

Base Config Settings

Trappable Errors (Ping Class)

Error Handling (C++)

Call the GetLastErrorCode() method to obtain the last called method's result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. Known error codes are listed below. If an error occurs, the GetLastError() method can be called to retrieve the associated error message.

Ping Errors

The class may also return one of the following error codes, which are inherited from other classes.

ICMP Errors

SSL Errors

TCP/IP Errors