snippets/c/sdprintf.c

24 lines
659 B
C

/*!
* \brief sdprintf printf to a dynamic buffer
* \param buf The character buffer. Will append if not NULL;
* \param offset Should be set to strlen when continuing a string. Will be incremented automatically.
* \param __format printf format string
* \return the number of bytes written
*/
int sdprintf(char **buf, int *offset, const char *__restrict __format, ...)
{
va_list vargs;
int len;
va_start(vargs, __format);
len = vsnprintf(NULL, 0, __format, vargs);
va_end(vargs);
*buf = realloc(*buf, *offset + len + 1);
va_start(vargs, __format);
len = vsprintf(*buf + *offset, __format, vargs);
va_end(vargs);
*offset += len;
return len;
}