t_alloc(3)						     Library Functions Manual							t_alloc(3)

NAME

       t_alloc() - allocate transport function library structure

SYNOPSIS

       -- or --

DESCRIPTION

       The  function  dynamically  allocates memory for the various transport function argument structures as specified below.	This function will
       allocate memory for the specified structure and will also allocate memory for buffers referenced by the structure.

       The structure to allocate is specified by struct_type and must be one of the following:

	      T_BIND	   struct   t_bind
	      T_CALL	   struct   t_call
	      T_DIS	   struct   t_discon
	      T_INFO	   struct   t_info
	      T_OPTMGMT    struct   t_optmgmt
	      T_UDERROR    struct   t_uderr
	      T_UNITDATA   struct   t_unitdata

       where each of these structures may subsequently be used as an argument to one or more transport functions.

       Each of the above structures, except T_INFO, contains at least one field of type For each field of this type, the user may specify that the
       buffer  for  that  field  should be allocated as well.  The length of the buffer allocated will be equal to or greater than the appropriate
       size returned in the info argument of or The relevant fields of the info argument are described in the following list.  The fields argument
       specifies which buffer to allocate, where the argument is the bitwise-OR of any of the following:

       The		   addr field of the or structures.

       The		   opt field of the or structures.

       The		   udata field of the or structures.

       All relevant fields of the given structure.
			   Fields which are not supported by e transport provider specified by fd will not be allocated (info values are <= 0).

       For each field specified in fields, will allocate memory for the buffer associated with the field, and initialize the len field to zero and
       the buf pointer and maxlen field accordingly.  Since the length of the buffer allocated will be based on the same size information that	is
       returned to the user on or fd must refer to the transport endpoint through which the newly allocated structure will be passed.  In this way
       the appropriate size information can be accessed.  If the size value associated with any specified field is -1 or -2  (	see  t_open(3)	or
       t_getinfo(3)),  will be unable to determine the size of the buffer to allocate and will fail, setting to and to For any field not specified
       in fields, buf will be set to a null pointer and maxlen will be set to zero.

       Use of to allocate structures will help ensure the compatibility of user programs with future releases of  the  transport  interface  func-
       tions.

   Valid States
       All, apart from

   Fork Safety
       is not fork-safe.

RETURN VALUE

       Upon successful completion, returns a pointer to the newly allocated structure.	On failure, a null pointer is returned.

ERRORS

       On failure, is set to one of the following:

       fd,	      the specified endpoint identifier, does not refer to a transport endpoint.

       A system error has occurred during execution of this function.

       (XTI only) This error indicates that a communication problem has been detected
		      between XTI and the transport provider for which there is no suitable XTI

       Unsupported    struct_type  requested.	This  can include a request for a structure type which is inconsistent with the transport provider
		      type specified, that is, connection-oriented or connectionless.

SEE ALSO

       t_free(3), t_getinfo(3), t_open(3), thread_safety(5).

STANDARDS CONFORMANCE

																	t_alloc(3)