line feed for printf("\n some text") about printf HOT 2 CLOSED

Hello @mgiaco ,
printf is just the string "transporter" for sprintf, which writes the formatted text to a given buffer.
So printf creates its own temp buffer of PRINTF_BUFFER_SIZE size, formats the given text and calls _putchar() char by char for output.
Any text without the format specifier (%) is copied directly into the output (string) like\n \r etc.

_putchar and printf have no idea how your terminal looks like. Some terminals just need a CR, others (like yours) need a CRLF to go the next line.
As you suspected, this is (normally) all handled in your custom _putchar() routine.
Something like:

void _putchar(char character)
{
  if (character == '\n') {
    send('\n');
    send('\r');
  }
  else {
    send(character);
}

send() is your terminal/serial/whatever output here.
Other terminals may need a translation to ESC sequences or something else...

Same if you implement \t \v tab support. If _putchar() processes this sequence you have to move the cursor to the next horizontal or vertical tab position with the emulation codes you use.

from printf.

okay many thanks.

from printf.