sprintf() without trailing null space in C

Question

Is there a way to use the C sprintf() function without it adding a \'\\0\' character at the end of its output? I need to write formatted text in the middle of a fixed width stri

Answer 1

Since you're writing to a fixed area, you can do it like this:

// pointer to fixed area we want to write to
char* s;

// number of bytes needed, not including the null
int r = snprintf(0, 0, );

// char following the last char we will write - null goes here
char c = s[r + 1];

// do the formatted write
snprintf(s, r + 1, );

// replace what was overwritten
s[r + 1] = c;