snprintf.c

OMAP1030 处理器的ARM 侧硬件测试代码 OMAP1030 是TI的双核处理器

/*****************************************************************************/
/*  SNPRINTF.C v2.24                                                        */
/*  Copyright (c) 2001-2002 Texas Instruments Incorporated                   */
/*****************************************************************************/

/*****************************************************************************/
/* Functions:                                                                */
/*    SNPRINTF -  Copy formatted output to a string                          */
/*    _OUTC    -  Put a character in a string                                */
/*    _OUTS    -  Append a string to another string                          */
/*****************************************************************************/
#include <stdio.h>
#include <format.h>
#include <stdarg.h>
#include <string.h>

extern int _printfi(char **_format, va_list _ap, void *_op,
		    int (*_outc)(char, void *), int (*_outs)(char *, void *));

static int _outc(char c, void *_op);
static int _outs(char *s, void *_op);

struct holder {
    char  *out_end;
    size_t n;
    size_t written;
};

/*****************************************************************************/
/* SNPRINTF  -  Copy formatted output to a string                            */
/*                                                                           */
/*    This function passes a format string and an argument list to           */
/*    _PRINTFI, and writes the result string to the string _STRING.          */
/*                                                                           */
/*****************************************************************************/
_CODE_ACCESS int snprintf(char *_string, size_t _n, const char *_format, ...)
{
    va_list _ap;
    int    rval;
    char  *fptr = (char *)_format;
    struct holder holder; 

    holder.out_end = _string;
    holder.n       = _n;
    holder.written = 0;

    va_start(_ap, _format);
    rval = _printfi(&fptr, _ap, (void *)&holder, _outc, _outs);
    va_end(_ap);

    if (_n) *holder.out_end = '\0';

    return rval;
}

/*****************************************************************************/
/* _OUTC -  Put a character in a string                                      */
/*****************************************************************************/
static int _outc(char c, void *_op)
{
    struct holder *holder = (struct holder *)_op;
    
    if (holder->written < holder->n)
	*holder->out_end++ = c;

    holder->written++;

    return c;
}

/*****************************************************************************/
/* _OUTS -  Append a string to another string                                */
/*****************************************************************************/
static int _outs(char *s, void *_op)
{
    struct holder *holder = (struct holder *)_op;
    size_t len = strlen(s);

    if (holder->written < holder->n)
    {
	size_t space = holder->n - holder->written;
	size_t use = len > space ? space : len;
	memcpy(holder->out_end, s, use);
	holder->out_end += use;
    }
    
    holder->written += len;

    return len;
}