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tiny_printf.c
tiny_printf.c 8.49 KiB
/**
*****************************************************************************
**
** File : tiny_printf.c
**
** Abstract : Atollic TrueSTUDIO Minimal iprintf/siprintf/fiprintf
** and puts/fputs.
** Provides aliased declarations for printf/sprintf/fprintf
** pointing to *iprintf variants.
**
** The argument contains a format string that may include
** conversion specifications. Each conversion specification
** is introduced by the character %, and ends with a
** conversion specifier.
**
** The following conversion specifiers are supported
** cdisuxX%
**
** Usage:
** c character
** d,i signed integer (-sign added, + sign not supported)
** s character string
** u unsigned integer as decimal
** x,X unsigned integer as hexadecimal (uppercase letter)
** % % is written (conversion specification is '%%')
**
** Note:
** Character padding is not supported
**
** Environment : Atollic TrueSTUDIO
**
** Distribution: The file is distributed "as is", without any warranty
** of any kind.
**
** (c)Copyright Atollic AB.
** You may use this file as-is or modify it according to the needs of your
** project. This file may only be built (assembled or compiled and linked)
** using the Atollic TrueSTUDIO(R) product. The use of this file together
** with other tools than Atollic TrueSTUDIO(R) is not permitted.
**
*****************************************************************************
*/
/* Includes */
#include <stdarg.h>
#include <stdio.h>
#include <string.h>
/* Create aliases for *printf to integer variants *iprintf */
__attribute__ ((alias("iprintf"))) int printf(const char *fmt, ...);
__attribute__ ((alias("fiprintf"))) int fprintf(FILE* fp, const char *fmt, ...);
__attribute__ ((alias("siprintf"))) int sprintf(char* str, const char *fmt, ...);
/* External function prototypes (defined in syscalls.c) */
extern int _write(int fd, char *str, int len);
/* Private function prototypes */
void ts_itoa(char **buf, unsigned int d, int base);
int ts_formatstring(char *buf, const char *fmt, va_list va);
int ts_formatlength(const char *fmt, va_list va);
/* Private functions */
/**
**---------------------------------------------------------------------------
** Abstract: Convert integer to ascii
** Returns: void
**---------------------------------------------------------------------------
*/
void ts_itoa(char **buf, unsigned int d, int base){
int div = 1;
while (d/div >= base)
div *= base;
while (div != 0)
{
int num = d/div;
d = d%div;
div /= base;
if (num > 9)
*((*buf)++) = (num-10) + 'A';
else
*((*buf)++) = num + '0';
}
}
/**
**---------------------------------------------------------------------------
** Abstract: Writes arguments va to buffer buf according to format fmt
** Returns: Length of string
**---------------------------------------------------------------------------
*/
int ts_formatstring(char *buf, const char *fmt, va_list va)
{
char *start_buf = buf;
while(*fmt)
{
/* Character needs formating? */
if (*fmt == '%')
{
switch (*(++fmt))
{
case 'c':
*buf++ = va_arg(va, int);
break;
case 'd':
case 'i':
{
signed int val = va_arg(va, signed int);
if (val < 0)
{
val *= -1;
*buf++ = '-';
}
ts_itoa(&buf, val, 10);
}
break;
case 's':
{
char * arg = va_arg(va, char *);
while (*arg)
{
*buf++ = *arg++;
}
}
break;
case 'u':
ts_itoa(&buf, va_arg(va, unsigned int), 10);
break;
case 'x':
case 'X':
ts_itoa(&buf, va_arg(va, int), 16);
break;
case '%':
*buf++ = '%';
break;
}
fmt++;
} /* Else just copy */
else
{
*buf++ = *fmt++;
}
}
*buf = 0;
return (int)(buf - start_buf);
}
/**
**---------------------------------------------------------------------------
** Abstract: Calculate maximum length of the resulting string from the
** format string and va_list va
** Returns: Maximum length
**---------------------------------------------------------------------------
*/
int ts_formatlength(const char *fmt, va_list va)
{
int length = 0;
while (*fmt)
{
if (*fmt == '%')
{
++fmt;
switch (*fmt)
{
case 'c':
va_arg(va, int);
++length;
break;
case 'd':
case 'i':
case 'u':
/* 32 bits integer is max 11 characters with minus sign */
length += 11;
va_arg(va, int);
break;
case 's':
{
char * str = va_arg(va, char *);
while (*str++)
++length;
}
break;
case 'x':
case 'X':
/* 32 bits integer as hex is max 8 characters */
length += 8;
va_arg(va, unsigned int);
break;
default:
++length;
break;
}
}
else
{
++length;
}
++fmt;
}
return length;
}
/**
**===========================================================================
** Abstract: Loads data from the given locations and writes them to the** given character string according to the format parameter.
** Returns: Number of bytes written
**===========================================================================
*/
int siprintf(char *buf, const char *fmt, ...)
{
int length;
va_list va;
va_start(va, fmt);
length = ts_formatstring(buf, fmt, va);
va_end(va);
return length;
}
/**
**===========================================================================
** Abstract: Loads data from the given locations and writes them to the
** given file stream according to the format parameter.
** Returns: Number of bytes written
**===========================================================================
*/
int fiprintf(FILE * stream, const char *fmt, ...)
{
int length = 0;
va_list va;
va_start(va, fmt);
length = ts_formatlength(fmt, va);
va_end(va);
{
char buf[length];
va_start(va, fmt);
length = ts_formatstring(buf, fmt, va);
length = _write(stream->_file, buf, length);
va_end(va);
}
return length;
}
/**
**===========================================================================
** Abstract: Loads data from the given locations and writes them to the
** standard output according to the format parameter.
** Returns: Number of bytes written
**
**===========================================================================
*/
int iprintf(const char *fmt, ...)
{
int length = 0;
va_list va;
va_start(va, fmt);
length = ts_formatlength(fmt, va);
va_end(va);
{
char buf[length];
va_start(va, fmt);
length = ts_formatstring(buf, fmt, va);
length = _write(1, buf, length);
va_end(va);
}
return length;
}
/**
**===========================================================================
** Abstract: fputs writes the string at s (but without the trailing null) to
** the file or stream identified by fp.
** Returns: If successful, the result is 0; otherwise, the result is EOF.
**
**===========================================================================*/
int fputs(const char *s, FILE *fp)
{
int length = strlen(s);
int wlen = 0;
int res;
wlen = _write((fp->_file), (char*)s, length);
wlen += _write((fp->_file), "\n", 1);
if (wlen == (length+1))
{
res = 0;
}
else
{
res = EOF;
}
return res;
}
/**
**===========================================================================
** Abstract: puts writes the string at s (followed by a newline, instead of
** the trailing null) to the standard output stream.
** Returns: If successful, the result is a nonnegative integer; otherwise,
** the result is EOF.
**
**===========================================================================
*/
int puts(const char *s)
{
int length = strlen(s);
int numbytes = 0;
int res;
numbytes = _write(1, (char*)s, length);
numbytes += _write(1, "\n", 1);
if (numbytes == (length+1))
{
res = 0;
}
else
{
res = EOF;
}
return res;
}
/**
**===========================================================================
** Abstract: Copy, starting from the memory location buf, count elements
** (each of size size) into the file or stream identified by fp.
** Returns: Number of elements written
**
**===========================================================================
*/
size_t fwrite(const void * buf, size_t size, size_t count, FILE * fp)
{
return (_write((fp->_file), (char*)buf, size * count) / size);
}