-int _printf (struct outdesc* d, char* f, va_list ap)
+int _printf (struct outdesc* d, const char* f, va_list ap)
{
outfunc fout; /* Output function */
unsigned char type; /* variable argument type */
register char* s; /* work pointer to argument string */
/* Remember the format string in a register variable for shorter code */
- register char* format = f;
+ register const char* format = f;
/* Remember the output function in a local variable for speed and size */
fout = d->fout;
/* Internal formatting routine */
-int _printf (struct outdesc* d, char* format, va_list ap);
+int _printf (struct outdesc* d, const char* format, va_list ap);