printf.c

LPC based lcd interface

#include <ctype.h>
#define TRUE	1
#define FALSE 0


printf(fmt, arg)
const char *fmt;
int arg;
{
        int ret;

        ret = __printf(fmt,&arg);
        return(ret);
}

__printf(fmt, args)
register unsigned char *fmt;
register unsigned int *args;
        {
        register int i, cnt = 0, ljustf, lval;
        int preci, dpoint, width;
        char pad, sign, radix;
        register char *ptmp;
        char tmp[64], *ltoa(), *ultoa();
#ifdef FLOATS
        double fx;
#endif

        while(*fmt)
                {
                if(*fmt == '%')
                        {
                        ljustf = FALSE; /* left justify flag */
                        sign = '\0';    /* sign char & status */
                        pad = ' ';      /* justification padding char */
                        width = -1;     /* min field width */
                        dpoint = FALSE; /* found decimal point */
                        preci = -1;     /* max data width */
                        radix = 10;     /* number base */
                        ptmp = tmp;     /* pointer to area to print */
                        lval = FALSE;   /* long value flaged */
fmtnxt:
                        i = 0;
                        while (isdigit(*++fmt))
                                {
                                i = (i * 10) + (*fmt - '0');
                                if (dpoint)
                                        preci = i;
                                else if (!i && (pad == ' '))
                                        {
                                        pad = '0';
                                        goto fmtnxt;
                                        }
                                else
                                        width = i;
                                }

                        switch(*fmt)
                                {
                                case '\0':      /* early EOS */
                                        --fmt;
                                        goto charout;

                                case '-':       /* left justification */
                                        ljustf = TRUE;
                                        goto fmtnxt;

                                case ' ':
                                case '+':       /* leading sign flag */
                                        sign = *fmt;
                                        goto fmtnxt;

                                case '*':       /* parameter width value */
                                        i = *args++;
                                        if (dpoint)
                                                preci = i;
                                        else
                                                width = i;
                                        goto fmtnxt;

                                case '.':       /* secondary width field */
                                        dpoint = TRUE;
                                        goto fmtnxt;

                                case 'l':       /* long data */
                                        lval = TRUE;
                                        goto fmtnxt;

                                case 'd':       /* Signed decimal */
                                case 'i':
                                        ltoa((long)((lval)
                                                ?(*((long *) args))
                                                :(*((int  *) args))),
                                              ptmp, 10);
                                        if(lval)
                                                args = ((unsigned int *)
                                                        (((long *) args) + 1));
                                        else
                                                args = ((unsigned int *)
                                                        (((int *) args) + 1));
                                        goto printit;

                                case 'b':       /* Unsigned binary */
                                        radix = 2;
                                        goto usproc;

                                case 'o':       /* Unsigned octal */
                                        radix = 8;
                                        goto usproc;

                                case 'p':       /* Pointer */
                                        lval = TRUE;
                                        pad = '0';
                                        width = 6;
                                        preci = 8;
                                        /* fall thru */

                                case 'x':       /* Unsigned hexadecimal */
                                case 'X':
                                        radix = 16;
                                        /* fall thru */

                                case 'u':       /* Unsigned decimal */
usproc:
                                        ultoa((unsigned long)((lval)
                                                ?(*((unsigned long *) args))
                                                : *args++ ),
                                              ptmp, radix);
                                        if(lval)
                                                args = ((unsigned int *)
                                                (((unsigned long *) args) + 1));
                                        if (*fmt == 'x')
                                                strlwr(ptmp, ptmp);
                                        goto printit;
                                case 'c':       /* Character */
                                        ptmp[0] = *args++;
                                        ptmp[1] = '\0';
                                        goto nopad;

                                case 's':       /* String */
                                        ptmp = *((char **) args);
                                        args = ((unsigned int *)
                                                (((char **) args) + 1));
nopad:
                                        sign = '\0';
                                        pad  = ' ';
printit:
                                        cnt += __prtfld(ptmp, ljustf,
                                                       sign, pad, width, preci);
                                        break;

                                default:        /* unknown character */
                                        goto charout;
                                }
                        }
                else
                        {
charout:
                      	sys_writec(*fmt);       /* normal char out */
                        ++cnt;
                        }
                ++fmt;
                }
        return(cnt);
        }

__prtfld(buf, ljustf, sign, pad, width, preci)
        register unsigned char *buf;
        int ljustf;
        register char sign;
        char pad;
        register int width;
        int preci;
/*
 *      Output the given field in the manner specified by the arguments.
 *      Return the number of characters output.
 */
        {
        register int cnt = 0, len;
        register unsigned char ch;

        len = strlen(buf);

        if (*buf == '-')
                sign = *buf++;
        else if (sign)
                len++;

        if ((preci != -1) && (len > preci))     /* limit max data width */
                len = preci;

        if (width < len)        /* flexible field width or width overflow */
                width = len;

/* at this point:
 *      width = total field width
 *      len   = actual data width (including possible sign character)
 */
        cnt = width;
        width -= len;

        while (width || len)
                {
                if (!ljustf && width)           /* left padding */
                        {
                        if (len && sign && (pad == '0'))
                                goto showsign;
                        ch = pad;
                        --width;
                        }
                else if (len)
                        {
                        if (sign)
                                {
showsign:                       ch = sign;      /* sign */
                                sign = '\0';
                                }
                        else
                                ch = *buf++;    /* main field */
                        --len;
                        }
                else
                        {
                        ch = pad;               /* right padding */
                        --width;
                        }
                sys_writec(ch);
                }

        return(cnt);
        }