Diff: printf.h

Revision:

0:aa3b196cf64f

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/printf.h	Fri May 17 12:49:09 2013 +0000
@@ -0,0 +1,107 @@
+/*
+File: printf.h
+
+Copyright (C) 2004  Kustaa Nyholm
+
+This library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Lesser General Public
+License as published by the Free Software Foundation; either
+version 2.1 of the License, or (at your option) any later version.
+
+This library is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public
+License along with this library; if not, write to the Free Software
+Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+This library is realy just two files: 'printf.h' and 'printf.c'.
+
+They provide a simple and small (+200 loc) printf functionality to
+be used in embedded systems.
+
+I've found them so usefull in debugging that I do not bother with a
+debugger at all.
+
+They are distributed in source form, so to use them, just compile them
+into your project.
+
+Two printf variants are provided: printf and sprintf.
+
+The formats supported by this implementation are: 'd' 'u' 'c' 's' 'x' 'X'.
+
+Zero padding and field width are also supported.
+
+If the library is compiled with 'PRINTF_SUPPORT_LONG' defined then the
+long specifier is also
+supported. Note that this will pull in some long math routines (pun intended!)
+and thus make your executable noticably longer.
+
+The memory foot print of course depends on the target cpu, compiler and
+compiler options, but a rough guestimate (based on a H8S target) is about
+1.4 kB for code and some twenty 'int's and 'char's, say 60 bytes of stack space.
+Not too bad. Your milage may vary. By hacking the source code you can
+get rid of some hunred bytes, I'm sure, but personally I feel the balance of
+functionality and flexibility versus  code size is close to optimal for
+many embedded systems.
+
+To use the printf you need to supply your own character output function,
+something like :
+
+void putc ( void* p, char c)
+{
+    while (!SERIAL_PORT_EMPTY) ;
+    SERIAL_PORT_TX_REGISTER = c;
+}
+
+Before you can call printf you need to initialize it to use your
+character output function with something like:
+
+init_printf(NULL,putc);
+
+Notice the 'NULL' in 'init_printf' and the parameter 'void* p' in 'putc',
+the NULL (or any pointer) you pass into the 'init_printf' will eventually be
+passed to your 'putc' routine. This allows you to pass some storage space (or
+anything realy) to the character output function, if necessary.
+This is not often needed but it was implemented like that because it made
+implementing the sprintf function so neat (look at the source code).
+
+The code is re-entrant, except for the 'init_printf' function, so it
+is safe to call it from interupts too, although this may result in mixed output.
+If you rely on re-entrancy, take care that your 'putc' function is re-entrant!
+
+The printf and sprintf functions are actually macros that translate to
+'tfp_printf' and 'tfp_sprintf'. This makes it possible
+to use them along with 'stdio.h' printf's in a single source file.
+You just need to undef the names before you include the 'stdio.h'.
+Note that these are not function like macros, so if you have variables
+or struct members with these names, things will explode in your face.
+Without variadic macros this is the best we can do to wrap these
+fucnction. If it is a problem just give up the macros and use the
+functions directly or rename them.
+
+For further details see source code.
+
+regs Kusti, 23.10.2004
+*/
+
+#ifndef __TFP_PRINTF__
+#define __TFP_PRINTF__
+
+#include <stdarg.h>
+
+void init_printf(void *putp, void (*putf) (void *, char));
+
+void tfp_printf(char *fmt, ...);
+void tfp_sprintf(char *s, char *fmt, ...);
+
+void tfp_format(void *putp, void (*putf) (void *, char), char *fmt, va_list va);
+
+#define mprintf tfp_printf
+#define msprintf tfp_sprintf
+
+#define PRINTF_LONG_SUPPORT
+
+#endif
\ No newline at end of file