gtpc2mff | C/C++ Language Support User's Guide |
This function returns the key value for the element pointed to by the cursor. The current key is returned for dictionaries, key bags, key sets, and key sorted bags. The sort field is returned for sorted bag and sorted set collections.
Format
#include <c$to2.h> TO2_BUF_PTR TO2_key (const TO2_PID_PTR cursorPidPtr, TO2_ENV_PTR env_ptr);
Normal Return
The normal return is a pointer (TO2_BUF_PTR) to a structure (buffer) of type TO2_BUF_HDR (see Type Definitions).
Error Return
An error return is indicated by a zero. When zero is returned, use the TO2_getErrorCode function to determine the specific error code. For more information, see Error Handling.
The following error codes are common for this function:
TO2_ERROR_CURSOR
TO2_ERROR_ENV
TO2_ERROR_METHOD
TO2_ERROR_PID
TO2_ERROR_ZERO_PID
Programming Considerations
Examples
The following example shows how the key value is retrieved from the item to which the cursor is currently pointing.
#include <c$to2.h> /* Needed for TO2 API Functions */ #include <stdio.h> /* APIs for standard I/O functions */ TO2_PID cursor; TO2_ENV_PTR env_ptr; TO2_BUF_PTR buffer_ptr; /* Pointer to returned buffer */ u_char *key; /* The key of the element */ TO2_ERR_CODE err_code; /* TO2 error code value */ TO2_ERR_TEXT_PTR err_text_ptr; /* TO2 error code text pointer */
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/**********************************************************************/ /* Retrieve the key from the item pointed to by the cursor. */ /**********************************************************************/ if ((buffer_ptr = TO2_key(&cursor, env_ptr)) == NULL) { printf("TO2_key failed!\n"); process_error(env_ptr); } else { key = buffer_ptr->data; printf("TO2_key successful!\n"); }
Related Information