c - How to allow variable parameters passed to function -

i have function accepts 3 parameters, want accept first 2 , not care third. how can in c. tried declaring function in header file void list() thinking might imply don't care how many parameters didn't work.

void list(uint8_t _pin, unsigned int time, unsigned long tasks) 

what want called variadic function. can accept variable number of arguments.

^{**famous examples: printf()/scanf()}

these functions contain ellipsis (…) notation in argument list, , uses special macros access variable arguments.

the basic idea write function accepts variable number of arguments. so, must declared prototype says so.

the syntax of iso c requires @ least 1 fixed argument before …. thus, write fixed arguments usual, , add … notain @ end of parameter list indicate possibility of additional arguments. example,

int func (const char *a, int b, …) {   … } 

defines function func() returns int , takes 2 required arguments, const char * , int. these followed number of anonymous arguments.

you can check on-line gnu manual more details.