Query: t_open
OS: osf1
Section: 3
Format: Original Unix Latex Style Formatted with HTML and a Horizontal Scroll Bar
t_open(3) Library Functions Manual t_open(3)NAMEt_open - Establishes a transport endpointLIBRARYXTI Library (libxti.a)SYNOPSIS#include <xti.h> #include <fcntl.h> int t_open( char *name, int oflag, struct t_info *info);STANDARDSInterfaces documented on this reference page conform to industry standards as follows: t_open(): XNS4.0 Refer to the standards(5) reference page for more information about industry standards and associated tags.PARAMETERSThe following table summarizes the relevance of input and output parameters before and after the t_open() function is called: ------------------------------------------ Parameter Before Call After Call ------------------------------------------ name y n oflag y n info->addr n y info->options n y info->tsdu n y info->etsdu n y info->connect n y info->discon n y info->servtype n y info->flags n y ------------------------------------------ Notes to Table: This is a meaningful parameter. This is not a meaningful parameter. Identifies the transport provider. The transport provider must define the type of transport service (protocol) to associate with the opened transport endpoint. [Tru64 UNIX] This implementation of XTI uses pathnames to device special files to identify transport providers. The device special files corresponding to TCP or UDP transport providers reside in the /dev/streams/xtiso directory. If you use a different transport provider, see its documentation for the correct device name. The oflag parameter is similar to the oflag parameter of the open() function and is used in the same way. Use oflag to establish synchronous or asynchronous operating modes of the transport provider pointed to by the name parameter. Specify O_RDWR to indicate that the endpoint supports reading and writing by functions and blocks on them, or specify the bitwise inclusive OR of O_RDWR and O_NONBLOCK to indicate that the endpoint supports the reading and writing by functions but does not block on them. These flags are defined in the <fcntl.h> header file. Points to a type t_info structure. The location of a type t_info structure is returned to the info parameter when the t_open() function successfully executes. Members of the t_info structure specify default characteristics of the underlying transport protocol pointed to by the name parameter. If a transport user sets the info parameter to the null pointer value, the function does not return any protocol information. When a transport user must preserve protocol independence, you can access the data length information defined by members of the type t_info structure to determine how large data buffers must be to hold exchanged data. If the transport user exceeds the allowed data size during any data exchange, you receive an error. Alternatively, you can use the t_alloc() function to allocate necessary data buffers. This structure has the following seven members: Permitted number of bytes in the protocol address. A value greater than zero indicates the maximum number of permitted bytes in a protocol address. A value of -1 specifies that there is no limit on the protocol address size. A value of -2 specifies that the transport provider does not permit the transport user access to the proto- col addresses. Permitted number of bytes of options. A value greater than zero indicates the maximum number of bytes of protocol- specific options supported by the transport provider. A value of -1 specifies that there is no limit to the number of options bytes. A value of -2 specifies that the transport provider does not permit a transport user to set options. Permitted number of bytes in a Transport Service Data Unit (TSDU). A value greater than zero specifies the maximum number of bytes in a TSDU message. A value of zero specifies that the transport provider does not support TSDU data exchanges, although it does support the sending of a data stream with no logical boundaries preserved across a connection. A value of -1 specifies that there is no limit to the number of bytes in a TSDU data exchange. A value of -2 specifies that the transfer of normal data is not supported by the transport provider. Permitted number of bytes in an Expedited Transport Service Data Unit (ETSDU). A value greater than zero specifies the maximum number of bytes in an ETSDU data exchange. A value of zero specifies that the transport provider does not support ETSDU data exchanges, although it does support the sending of an expedited data stream with no logical boundaries preserved across a connection. A value of -1 specifies that there is no limit on the number of bytes in an ETSDU data exchange. A value of -2 specifies that the transfer of expedited data is not supported by the transport provider. Permitted number of bytes of data in connect request. A value greater than zero specifies the maximum number of data bytes that may be exchanged using the t_connect() and t_rcvconnect() functions. A value of -2 specifies that the transport provider does not permit data to be sent when a connection is established. Permitted number of bytes of data in a disconnect request. A value greater than zero specifies the maximum number of data bytes that may be exchanged using the t_snddis() and t_rcvdis() func- tions. A value of -1 specifies that there is no limit to the number of data bytes that may be sent when a connection is closed using these abortive release functions. A value of -2 specifies that the transport provider does not permit data to be sent with an abortive release function. This member specifies only one of the following types of service supported by the transport provider: The transport provider supports connection-mode service but does not support the optional orderly release facility. The transport provider supports connection-mode service with the optional orderly release facility. The transport provider supports connection- less-mode service. For this service type, this function returns the value -2 for the etsdu, connect, and discon parameters. Speci- fies other information about the transport provider. If the T_SENDZERO bit is set in flags, this indicates the underlying transport provider supports the sending of zero-length TSDUs.VALID STATESThe t_open() function can be called in the T_UNINIT transport provider state only.DESCRIPTIONThe t_open() XTI function must be the first one called when initializing a transport endpoint. Two modes of operation may be specified, synchronous and asynchronous. In synchronous mode, a transport user must wait for some specific event to occur before control is returned (refer to the t_look() function). In asynchronous mode, a transport user is not required to wait for the event to occur; control is returned immediately. The t_open() function establishes the transport endpoint by supplying a transport provider identifier that specifies a particular transport protocol. A file descriptor, which must subsequently always be used to identify the established endpoint, is returned by this function.RETURN VALUESUpon successful completion, the t_open function returns a file descriptor, a nonnegative integer. Otherwise, a value of -1 is returned and t_errno is set to indicate the error.ERRORSIf the t_open() function fails, t_errno may be set to one of the following values: An invalid flag is specified. Invalid transport provider name. A system error occurred during execution of this function. This error indicates that a communication problem has been detected between XTI and the transport provider for which there is no other suitable XTI(t_errno).RELATED INFORMATIONFunctions: open(2) Standards: standards(5) delim off t_open(3)