variable number of arguments to a function in C using va_list, va_arg,va_start .

[Humble]

Everyone knows about it, so just a summary about it.

Yes, C allows a function to be prototyped to accept variable number of arguments from the caller..

Its done with the help of stdarg header.. The representation looks like below:

int func( int first, ... )

Note the ellipsis in form "..." , it will be the last argument in the function prototype..

Some of the macros defined in stdarg.h do the job of variable argument list parsing..

va_list  - The variable argument list should be of va_list type
va_start - initializes the list, 
va_arg   - returns the next argument in the list, and 
va_end   - cleans up the variable argument list. 


Now, va_start() requires 2 arguments . Those are va_list object and the last one in the fixed argument list.. 
va_arg() requires 2 arguments and those are va_list object and the argument type.. 

Isnt it easy ?

[Author]

Posts