t_alloc(3N)           (Networking Support Utilities)            t_alloc(3N)


   NAME
         talloc - allocate a library structure

   SYNOPSIS
         #include <tiuser.h>

         char *talloc(fd, structtype, fields)
         int fd;
         int structtype;
         int fields;

   DESCRIPTION
         The talloc 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 structtype, and can be one
         of the following:

         TBIND           struct tbind

         TCALL           struct tcall

         TOPTMGMT        struct toptmgmt

         TDIS            struct tdiscon

         TUNITDATA       struct tunitdata

         TUDERROR        struct tuderr

         TINFO           struct tinfo

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

         Each of the above structures, except TINFO, contains at least one
         field of type struct netbuf.  netbuf is described in intro(3).  For
         each field of this type, the user may specify that the buffer for
         that field should be allocated as well.  The fields argument
         specifies this option, where the argument is the bitwise-OR of any of
         the following:

         TADDR    The addr field of the tbind, tcall, tunitdata, or
                   tuderr structures.

         TOPT     The opt field of the toptmgmt, tcall, tunitdata, or
                   tuderr structures.




   8/91                                                                 Page 1

   t_alloc(3N)           (Networking Support Utilities)            t_alloc(3N)


         TUDATA   The udata field of the tcall, tdiscon, or tunitdata
                   structures.

         TALL     All relevant fields of the given structure.

         For each field specified in fields, talloc will allocate memory for
         the buffer associated with the field, and initialize the buf pointer
         and maxlen [see netbuf in intro(3) for description of buf and maxlen]
         field accordingly.  The length of the buffer allocated will be based
         on the same size information that is returned to the user on topen
         and tgetinfo.  Thus, fd must refer to the transport endpoint through
         which the newly allocated structure will be passed, so that the
         appropriate size information can be accessed.  If the size value
         associated with any specified field is -1 or -2 (see topen or
         tgetinfo), talloc will be unable to determine the size of the
         buffer to allocate and will fail, setting terrno to TSYSERR and
         errno to EINVAL.  For any field not specified in fields, buf will be
         set to NULL and maxlen will be set to zero.

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

         On failure, terrno may be set to one of the following:

         [TBADF]        The specified file descriptor does not refer to a
                        transport endpoint.

         [TSYSERR]      A system error has occurred during execution of this
                        function.

   SEE ALSO
         intro(3), tfree(3N), tgetinfo(3N), topen(3N).
         Programmer's Guide: Networking Interfaces.

   DIAGNOSTICS
         On successful completion, talloc returns a pointer to the newly
         allocated structure.  On failure, NULL is returned.















   Page 2                                                                 8/91