Process incoming serial stream without LF CR

Question

The code below processes incoming RS232 serial data 1 character at a time and works fine.

However the incoming serial feed in my use case does not contain any CR or LF characters which make further delimiting/processing to a piped program difficult. The end delimiter is always a ! exclamation character instead of a CR or LF. e.g. 123456!abcdef!qwerty!

Is there a way to modify the code below to substitute the ! character to a CR (carriage return)? For example, is the incoming string is 123456abcdef! then the program should replace the ! with a CR so it outputs 123456abcdef<carriage return>

#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <wiringSerial.h>

int main ()

  for (;;)
  {
    putchar (serialGetchar (fd)) ;
    fflush (stdout) ;
  }
}

Answer 1

You can do it in the same single char basis as:

#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <wiringSerial.h>

int main ()

  for (;;)
  {
    char c = serialGetchar (fd);
    putchar (c == '!' ? '\r' : c) ;
    fflush (stdout) ;
  }
}

Normally it is used new line with carriage return, in that case would be:

#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <wiringSerial.h>

int main ()

  for (;;)
  {
    char c = serialGetchar (fd);
    if (c == '!')
    {
        putchar ('\r') ;
        putchar ('\n') ;
    }
    else
    {
        putchar (c) ;
    }
    fflush (stdout) ;
  }
}