printf "%*s" format

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printf "%*s" format

Paul "LeoNerd" Evans
I often find it useful to be able to print a character buffer of
dynamically-known size by using some variant on

  printf("%.*s", len, buf);

It appears to me that avr-libc doesn't recognise this particular flag.
Neither the documentation nor the implementation in vfprintf.c seem to
mention it. If I try it, it just gives up. E.g.

  uint8_t len;
  uint8_t buf[16];
  printf("BUF=%d <%.*s>\n", len, len, buf);

I get output simply

  BUF=4 <

it stops parsing at the .*, and doesn't even get as far as printing the
'>' and trailing linefeed.

Would folk be amenable to a patch to add this feature? To my eye it
doesn't look like it would be more than about a 5-line change to add
it, I don't think it would massively increase code size.

But I thought I'd ask first, in case there's some specific reason for
its absence.

Paul "LeoNerd" Evans

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