c - converting sprintf to snprintf using MACRO -

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we have code following:

#define maxint  1000000000  #define sprintf(a, b, c)    ((sizeof (a) > 8) ? snprintf(a, sizeof (a), b, c) : snprintf(a, maxint, b, c))                             // avoids buffer overrun static buffers of size > 8 else behaves default sprintf()                             // note max. size of char pointer 8, if sizeof (a) > 8, means static array

i remember developer asked convert sprintf() safer version snprintf() , did change shown above.

i understand above macro avoids buffer corruption static buffers of size > 8 , other i.e. dynamic buffers , static buffers of size <=8 behaves normal sprintf() assuming string being copied not greater "maxint". correct?

for ex. if string being copied less dest buffer or greater dest buffer, statement/above macro behave correctly either snprintf(a, sizeof(a), b, c) or normal default sprintf() - kind of ok behaviour time being. assume never fill dest buffer maxint (too big , src string never big) amount of characters?

the macro has conditional 'a > 8' check if of type char* or char[]. if char*, there no way of knowing how memory allocated , how can write it. if char[], know how memory reserved it. char[], can use snprintf , thereby safer ensuring never overrun. char*, cannot offer same. code assuming never want write more maxint.

if writing macro, have changed snprintf(a, maxint, b, c) sprintf(a, b, c) make clearer unable offer guarantees in scenario.


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