rprintf_8c-source.html

ATMEL的AVR单片机库文件

00585 <span class="comment">// code below this line is commented out and can be ignored</span>
00586 <span class="comment">//******************************************************************************</span>
00587 <span class="comment">/*</span>
00588 <span class="comment">char* sprintf(const char *sfmt, ...)</span>
00589 <span class="comment">{</span>
00590 <span class="comment">    register unsigned char *f, *bp, *str;</span>
00591 <span class="comment">    register long l;</span>
00592 <span class="comment">    register unsigned long u;</span>
00593 <span class="comment">    register int i;</span>
00594 <span class="comment">    register int fmt;</span>
00595 <span class="comment">    register unsigned char pad = ' ';</span>
00596 <span class="comment">    int     flush_left = 0, f_width = 0, prec = INF, hash = 0, do_long = 0;</span>
00597 <span class="comment">    int     sign = 0;</span>
00598 <span class="comment"></span>
00599 <span class="comment">    va_list ap;</span>
00600 <span class="comment">    va_start(ap, sfmt);</span>
00601 <span class="comment"></span>
00602 <span class="comment">    str = bufstring;</span>
00603 <span class="comment">    f = (unsigned char *) sfmt;</span>
00604 <span class="comment"></span>
00605 <span class="comment">    for (; *f; f++)</span>
00606 <span class="comment">    {</span>
00607 <span class="comment">        if (*f != '%')</span>
00608 <span class="comment">        {                               // not a format character</span>
00609 <span class="comment">            *str++ = (*f);          // then just output the char</span>
00610 <span class="comment">        }</span>
00611 <span class="comment">        else </span>
00612 <span class="comment">        {</span>
00613 <span class="comment">            f++;                        // if we have a "%" then skip it</span>
00614 <span class="comment">            if (*f == '-')</span>
00615 <span class="comment">            {</span>
00616 <span class="comment">                flush_left = 1; // minus: flush left</span>
00617 <span class="comment">                f++;</span>
00618 <span class="comment">            }</span>
00619 <span class="comment">            if (*f == '0' || *f == '.')</span>
00620 <span class="comment">                {</span>
00621 <span class="comment">                    // padding with 0 rather than blank</span>
00622 <span class="comment">                    pad = '0';</span>
00623 <span class="comment">                    f++;</span>
00624 <span class="comment">            }</span>
00625 <span class="comment">            if (*f == '*')</span>
00626 <span class="comment">                {   // field width</span>
00627 <span class="comment">                    f_width = va_arg(ap, int);</span>
00628 <span class="comment">                    f++;</span>
00629 <span class="comment">            }</span>
00630 <span class="comment">            else if (Isdigit(*f))</span>
00631 <span class="comment">                {</span>
00632 <span class="comment">                    f_width = atoi((char *) f);</span>
00633 <span class="comment">                    while (Isdigit(*f))</span>
00634 <span class="comment">                        f++;        // skip the digits</span>
00635 <span class="comment">            }</span>
00636 <span class="comment">            if (*f == '.')</span>
00637 <span class="comment">                {   // precision</span>
00638 <span class="comment">                    f++;</span>
00639 <span class="comment">                    if (*f == '*')</span>
00640 <span class="comment">                    {</span>
00641 <span class="comment">                        prec = va_arg(ap, int);</span>
00642 <span class="comment">                        f++;</span>
00643 <span class="comment">                    }</span>
00644 <span class="comment">                    else if (Isdigit(*f))</span>
00645 <span class="comment">                    {</span>
00646 <span class="comment">                        prec = atoi((char *) f);</span>
00647 <span class="comment">                        while (Isdigit(*f))</span>
00648 <span class="comment">                            f++;    // skip the digits</span>
00649 <span class="comment">                    }</span>
00650 <span class="comment">                }</span>
00651 <span class="comment">            if (*f == '#')</span>
00652 <span class="comment">                {   // alternate form</span>
00653 <span class="comment">                    hash = 1;</span>
00654 <span class="comment">                    f++;</span>
00655 <span class="comment">            }</span>
00656 <span class="comment">            if (*f == 'l')</span>
00657 <span class="comment">                {   // long format</span>
00658 <span class="comment">                    do_long = 1;</span>
00659 <span class="comment">                    f++;</span>
00660 <span class="comment">            }</span>
00661 <span class="comment"></span>
00662 <span class="comment">                fmt = *f;</span>
00663 <span class="comment">                bp = buf;</span>
00664 <span class="comment">                switch (fmt) {      // do the formatting</span>
00665 <span class="comment">                case 'd':           // 'd' signed decimal</span>
00666 <span class="comment">                    if (do_long)</span>
00667 <span class="comment">                        l = va_arg(ap, long);</span>
00668 <span class="comment">                    else</span>
00669 <span class="comment">                        l = (long) (va_arg(ap, int));</span>
00670 <span class="comment">                    if (l &lt; 0)</span>
00671 <span class="comment">                    {</span>
00672 <span class="comment">                        sign = 1;</span>
00673 <span class="comment">                        l = -l;</span>
00674 <span class="comment">                    }</span>
00675 <span class="comment">                    do  {</span>
00676 <span class="comment">                        *bp++ = l % 10 + '0';</span>
00677 <span class="comment">                    } while ((l /= 10) &gt; 0);</span>
00678 <span class="comment">                    if (sign)</span>
00679 <span class="comment">                        *bp++ = '-';</span>
00680 <span class="comment">                    f_width = f_width - (bp - buf);</span>
00681 <span class="comment">                    if (!flush_left)</span>
00682 <span class="comment">                        while (f_width-- &gt; 0)</span>
00683 <span class="comment">                            *str++ = (pad);</span>
00684 <span class="comment">                    for (bp--; bp &gt;= buf; bp--)</span>
00685 <span class="comment">                        *str++ = (*bp);</span>
00686 <span class="comment">                    if (flush_left)</span>
00687 <span class="comment">                        while (f_width-- &gt; 0)</span>
00688 <span class="comment">                            *str++ = (' ');</span>
00689 <span class="comment">                    break;</span>
00690 <span class="comment">            case 'o':           // 'o' octal number</span>
00691 <span class="comment">            case 'x':           // 'x' hex number</span>
00692 <span class="comment">            case 'u':           // 'u' unsigned decimal</span>
00693 <span class="comment">                    if (do_long)</span>
00694 <span class="comment">                        u = va_arg(ap, unsigned long);</span>
00695 <span class="comment">                    else</span>
00696 <span class="comment">                        u = (unsigned long) (va_arg(ap, unsigned));</span>
00697 <span class="comment">                    if (fmt == 'u')</span>
00698 <span class="comment">                    {   // unsigned decimal</span>
00699 <span class="comment">                        do {</span>
00700 <span class="comment">                            *bp++ = u % 10 + '0';</span>
00701 <span class="comment">                        } while ((u /= 10) &gt; 0);</span>
00702 <span class="comment">                    }</span>
00703 <span class="comment">                    else if (fmt == 'o')</span>
00704 <span class="comment">                    {  // octal</span>
00705 <span class="comment">                        do {</span>
00706 <span class="comment">                            *bp++ = u % 8 + '0';</span>
00707 <span class="comment">                        } while ((u /= 8) &gt; 0);</span>
00708 <span class="comment">                        if (hash)</span>
00709 <span class="comment">                            *bp++ = '0';</span>
00710 <span class="comment">                    }</span>
00711 <span class="comment">                    else if (fmt == 'x')</span>
00712 <span class="comment">                    {   // hex</span>
00713 <span class="comment">                        do {</span>
00714 <span class="comment">                            i = u % 16;</span>
00715 <span class="comment">                            if (i &lt; 10)</span>
00716 <span class="comment">                                *bp++ = i + '0';</span>
00717 <span class="comment">                            else</span>
00718 <span class="comment">                                *bp++ = i - 10 + 'a';</span>
00719 <span class="comment">                        } while ((u /= 16) &gt; 0);</span>
00720 <span class="comment">                        if (hash)</span>
00721 <span class="comment">                        {</span>
00722 <span class="comment">                            *bp++ = 'x';</span>
00723 <span class="comment">                            *bp++ = '0';</span>
00724 <span class="comment">                        }</span>
00725 <span class="comment">                    }</span>
00726 <span class="comment">                    i = f_width - (bp - buf);</span>
00727 <span class="comment">                    if (!flush_left)</span>
00728 <span class="comment">                        while (i-- &gt; 0)</span>
00729 <span class="comment">                            *str++ = (pad);</span>
00730 <span class="comment">                    for (bp--; bp &gt;= buf; bp--)</span>
00731 <span class="comment">                        *str++ = ((int) (*bp));</span>
00732 <span class="comment">                    if (flush_left)</span>
00733 <span class="comment">                        while (i-- &gt; 0)</span>
00734 <span class="comment">                            *str++ = (' ');</span>
00735 <span class="comment">                    break;</span>
00736 <span class="comment">            case 'c':           // 'c' character</span>
00737 <span class="comment">                    i = va_arg(ap, int);</span>
00738 <span class="comment">                    *str++ = ((int) (i));</span>
00739 <span class="comment">                    break;</span>
00740 <span class="comment">            case 's':           // 's' string</span>
00741 <span class="comment">                    bp = va_arg(ap, unsigned char *);</span>
00742 <span class="comment">                    if (!bp)</span>
00743 <span class="comment">                        bp = (unsigned char *) "(nil)";</span>
00744 <span class="comment">                    f_width = f_width - strlen((char *) bp);</span>
00745 <span class="comment">                    if (!flush_left)</span>
00746 <span class="comment">                        while (f_width-- &gt; 0)</span>
00747 <span class="comment">                            *str++ = (pad);</span>
00748 <span class="comment">                    for (i = 0; *bp &amp;&amp; i &lt; prec; i++)</span>
00749 <span class="comment">                    {</span>
00750 <span class="comment">                        *str++ = (*bp);</span>
00751 <span class="comment">                        bp++;</span>
00752 <span class="comment">                    }</span>
00753 <span class="comment">                    if (flush_left)</span>
00754 <span class="comment">                        while (f_width-- &gt; 0)</span>
00755 <span class="comment">                            *str++ = (' ');</span>
00756 <span class="comment">                    break;</span>
00757 <span class="comment">            case '%':           // '%' character</span>
00758 <span class="comment">                    *str++ = ('%');</span>
00759 <span class="comment">                    break;</span>
00760 <span class="comment">            }</span>
00761 <span class="comment">            flush_left = 0, f_width = 0, prec = INF, hash = 0, do_long = 0;</span>
00762 <span class="comment">            sign = 0;</span>
00763 <span class="comment">            pad = ' ';</span>
00764 <span class="comment">        }</span>
00765 <span class="comment">    }</span>
00766 <span class="comment"></span>
00767 <span class="comment">    va_end(ap);</span>
00768 <span class="comment">    // terminate string with null</span>
00769 <span class="comment">    *str++ = '\0';</span>
00770 <span class="comment">    return bufstring;</span>
00771 <span class="comment">}</span>
00772 <span class="comment"></span>
00773 <span class="comment">*/</span>
</pre></div><hr size="1"><address style="align: right;"><small>Generated on Fri Oct 15 03:50:22 2004 for Procyon AVRlib by
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</a>1.3.6 </small></address>
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