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HP-UX Reference > Tt_alloc(3)HP-UX 11i Version 2: December 2007 Update |
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NAMEt_alloc() — allocate a library structure SYNOPSIS#include <xti.h> /* for X/OPEN Transport Interface - XTI */ /* or */ #include <tiuser.h> /* for Transport Layer Interface - TLI */ char *t_alloc (fd, struct_type, fields); int fd; int struct_type; int fields; DESCRIPTIONThe t_alloc() 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:
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 struct netbuf. 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 t_open() or t_getinfo(). 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:
For each field specified in fields, t_alloc() 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 t_open() or t_getinfo(), 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)), t_alloc() will be unable to determine the size of the buffer to allocate and will fail, setting t_errno to [TSYSERR] and errno to [EINVAL]. For any field not specified in fields, buf will be set to a null pointer and maxlen will be set to zero. Use of t_alloc() to allocate structures will help ensure the compatibility of user programs with future releases of the transport interface functions. RETURN VALUEUpon successful completion, t_alloc() returns a pointer to the newly allocated structure. On failure, a null pointer is returned. ERRORSOn failure, t_errno is set to one of the following:
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