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Altera_Forum's avatar
Altera_Forum
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15 years ago

Passing Structures into Functions

Hi Guys, question I need some clarification on passing structures into functions. in what i'll outline below, i don't understand why the function prototypes are as they are. This is how...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
15 years ago

There is a typedef at the very beginning of the code making SSSConn visible as a type (alias 'struct SSS_SOCKET').

If you reformat the source a bit it becomes beter visible 


typedef  struct SSS_SOCKET { 
    enum { READY, COMPLETE, CLOSE } state; 
    int fd; 
    int close; 
    INT8U rx_buffer; 
    INT8U *rx_rd_pos; /* position we've read up to */
    INT8U *rx_wr_pos; /* position we've written up to */
    } SSSConn;

Most often we first see the declaration of the structure, followed by the typedef statement. 


struct SSS_SOCKET { 
    enum { READY, COMPLETE, CLOSE } state; 
    int fd; 
    int close; 
    INT8U rx_buffer; 
    INT8U *rx_rd_pos; /* position we've read up to */
    INT8U *rx_wr_pos; /* position we've written up to */
    } ;
typedef struct SSS_SOCKET SSSConn ;

The first code snippet does the two in one go.