printf.c

/*-
 * Copyright (c) 1986, 1988, 1991, 1993
 * The Regents of the University of California.  All rights reserved.
 * (c) UNIX System Laboratories, Inc.
 * All or some portions of this file are derived from material licensed
 * to the University of California by American Telephone and Telegraph
 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
 * the permission of UNIX System Laboratories, Inc.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * @(#)subr_prf.c 8.3 (Berkeley) 1/21/94
 */

#include "libc.h"

typedef unsigned char u_char;
typedef unsigned int u_int;
typedef unsigned long u_long;
typedef unsigned short u_short;
typedef unsigned long long u_quad_t;
typedef long long quad_t;
#define NBBY    8           /* number of bits in a byte */
static const char hex2ascii_data[] = "0123456789abcdefghijklmnopqrstuvwxyz";
#define hex2ascii(hex)  (hex2ascii_data[hex])
#define toupper(c) ((c) - 0x20 * (((c) >= 'a') && ((c) <= 'z')))

/* Max number conversion buffer length: a u_quad_t in base 2, plus NUL byte. */
#define MAXNBUF (sizeof(intmax_t) * NBBY + 1)

/*
 * Put a NUL-terminated ASCII number (base <= 36) in a buffer in reverse
 * order; return an optional length and a pointer to the last character
 * written in the buffer (i.e., the first character of the string).
 * The buffer pointed to by `nbuf' must have length >= MAXNBUF.
 */
static char *
ksprintn(char *nbuf, u_quad_t num, int base, int *lenp, int upper)
{
    char *p, c;

    p = nbuf;
    *p = '\0';
    do {
        c = hex2ascii(num % base);
        *++p = upper ? toupper(c) : c;
    } while (num /= base);
    if(lenp)
        *lenp = p - nbuf;
    return (p);
}

/*
 * Scaled down version of printf(3).
 *
 * Two additional formats:
 *
 * The format %b is supported to decode error registers.
 * Its usage is:
 *
 * printf("reg=%b\n", regval, "*");
 *
 * where  is the output base expressed as a control character, e.g.
 * \10 gives octal; \20 gives hex.  Each arg is a sequence of characters,
 * the first of which gives the bit number to be inspected (origin 1), and
 * the next characters (up to a control character, i.e. a character <= 32),
 * give the name of the register.  Thus:
 *
 * kvprintf("reg=%b\n", 3, "\10\2BITTWO\1BITONE\n");
 *
 * would produce output:
 *
 * reg=3
 *
 * XXX:  %D  -- Hexdump, takes pointer and separator string:
 *  ("%6D", ptr, ":")   -> XX:XX:XX:XX:XX:XX
 *  ("%*D", len, ptr, " " -> XX XX XX XX ...
 */
static int
kvprintf(char const *fmt, int (*func)(int), void *arg, int radix, va_list ap)
{
#define PCHAR(c) {char cc=(c); (*func)(cc); retval++; }
    char nbuf[MAXNBUF];
    const char *p, *percent, *q;
    u_char *up;
    int ch, n;
    u_quad_t num;
    int base, lflag, qflag, tmp, width, ladjust, sharpflag, neg, sign, dot;
    int cflag, hflag, jflag, tflag, zflag;
    int dwidth, upper;
    char padc;
    int stop = 0, retval = 0;

    num = 0;

    if(fmt == NULL)
        fmt = "(fmt null)\n";

    if(radix < 2 || radix > 36)
        radix = 10;

    for(;;) {
        padc = ' ';
        width = 0;
        while ((ch = (u_char)*fmt++) != '%' || stop) {
            if(ch == '\0')
                return (retval);
            PCHAR(ch);
        }
        percent = fmt - 1;
        qflag = 0; lflag = 0; ladjust = 0; sharpflag = 0; neg = 0;
        sign = 0; dot = 0; dwidth = 0; upper = 0;
        cflag = 0; hflag = 0; jflag = 0; tflag = 0; zflag = 0;
reswitch: switch (ch = (u_char)*fmt++) {
        case '.':
            dot = 1;
            goto reswitch;
        case '#':
            sharpflag = 1;
            goto reswitch;
        case '+':
            sign = 1;
            goto reswitch;
        case '-':
            ladjust = 1;
            goto reswitch;
        case '%':
            PCHAR(ch);
            break;
        case '*':
            if(!dot) {
                width = va_arg(ap, int);
                if(width < 0) {
                    ladjust = !ladjust;
                    width = -width;
                }
            } else {
                dwidth = va_arg(ap, int);
            }
            goto reswitch;
        case '0':
            if(!dot) {
                padc = '0';
                goto reswitch;
            }
        case '1': case '2': case '3': case '4':
        case '5': case '6': case '7': case '8': case '9':
                for(n = 0;; ++fmt) {
                    n = n * 10 + ch - '0';
                    ch = *fmt;
                    if(ch < '0' || ch > '9')
                        break;
                }
            if(dot)
                dwidth = n;
            else
                width = n;
            goto reswitch;
        case 'b':
            num = (u_int)va_arg(ap, int);
            p = va_arg(ap, char *);
            for(q = ksprintn(nbuf, num, *p++, NULL, 0); *q;)
                PCHAR(*q--);

            if(num == 0)
                break;

            for(tmp = 0; *p;) {
                n = *p++;
                if(num & (1 << (n - 1))) {
                    PCHAR(tmp ? ',' : '<');
                    for(; (n = *p) > ' '; ++p)
                        PCHAR(n);
                    tmp = 1;
                } else
                    for(; *p > ' '; ++p)
                        continue;
            }
            if(tmp)
                PCHAR('>');
            break;
        case 'c':
            PCHAR(va_arg(ap, int));
            break;
        case 'D':
            up = va_arg(ap, u_char *);
            p = va_arg(ap, char *);
            if(!width)
                width = 16;
            while(width--) {
                PCHAR(hex2ascii(*up >> 4));
                PCHAR(hex2ascii(*up & 0x0f));
                up++;
                if(width)
                    for(q=p;*q;q++)
                        PCHAR(*q);
            }
            break;
        case 'd':
        case 'i':
            base = 10;
            sign = 1;
            goto handle_sign;
        case 'h':
            if(hflag) {
                hflag = 0;
                cflag = 1;
            } else
                hflag = 1;
            goto reswitch;
        case 'j':
            jflag = 1;
            goto reswitch;
        case 'l':
            if(lflag) {
                lflag = 0;
                qflag = 1;
            } else
                lflag = 1;
            goto reswitch;
        case 'n':
            if(jflag)
                *(va_arg(ap, intmax_t *)) = retval;
            else if(qflag)
                *(va_arg(ap, quad_t *)) = retval;
            else if(lflag)
                *(va_arg(ap, long *)) = retval;
            else if(zflag)
                *(va_arg(ap, size_t *)) = retval;
            else if(hflag)
                *(va_arg(ap, short *)) = retval;
            else if(cflag)
                *(va_arg(ap, char *)) = retval;
            else
                *(va_arg(ap, int *)) = retval;
            break;
        case 'o':
            base = 8;
            goto handle_nosign;
        case 'p':
            base = 16;
            sharpflag = (width == 0);
            sign = 0;
            num = (uintptr_t)va_arg(ap, void *);
            goto number;
        case 'q':
            qflag = 1;
            goto reswitch;
        case 'r':
            base = radix;
            if(sign)
                goto handle_sign;
            goto handle_nosign;
        case 's':
            p = va_arg(ap, char *);
            if(p == NULL)
                p = "(null)";
            if(!dot)
                n = strlen (p);
            else
                for(n = 0; n < dwidth && p[n]; n++)
                    continue;

            width -= n;

            if(!ladjust && width > 0)
                while (width--)
                    PCHAR(padc);
            while (n--)
                PCHAR(*p++);
            if(ladjust && width > 0)
                while (width--)
                    PCHAR(padc);
            break;
        case 't':
            tflag = 1;
            goto reswitch;
        case 'u':
            base = 10;
            goto handle_nosign;
        case 'X':
            upper = 1;
        case 'x':
            base = 16;
            goto handle_nosign;
        case 'y':
            base = 16;
            sign = 1;
            goto handle_sign;
        case 'z':
            zflag = 1;
            goto reswitch;
handle_nosign:
            sign = 0;
            if(jflag)
                num = va_arg(ap, uintmax_t);
            else if(qflag)
                num = va_arg(ap, u_quad_t);
            else if(tflag)
                num = va_arg(ap, ptrdiff_t);
            else if(lflag)
                num = va_arg(ap, u_long);
            else if(zflag)
                num = va_arg(ap, size_t);
            else if(hflag)
                num = (u_short)va_arg(ap, int);
            else if(cflag)
                num = (u_char)va_arg(ap, int);
            else
                num = va_arg(ap, u_int);
            goto number;
handle_sign:
            if(jflag)
                num = va_arg(ap, intmax_t);
            else if(qflag)
                num = va_arg(ap, quad_t);
            else if(tflag)
                num = va_arg(ap, ptrdiff_t);
            else if(lflag)
                num = va_arg(ap, long);
            else if(zflag)
                num = va_arg(ap, ssize_t);
            else if(hflag)
                num = (short)va_arg(ap, int);
            else if(cflag)
                num = (char)va_arg(ap, int);
            else
                num = va_arg(ap, int);
number:
            if(sign && (quad_t)num < 0) {
                neg = 1;
                num = -(quad_t)num;
            }
            p = ksprintn(nbuf, num, base, &tmp, upper);
            if(sharpflag && num != 0) {
                if(base == 8)
                    tmp++;
                else if(base == 16)
                    tmp += 2;
            }
            if(neg)
                tmp++;

            if(!ladjust && padc != '0' && width
                && (width -= tmp) > 0)
                while (width--)
                    PCHAR(padc);
            if(neg)
                PCHAR('-');
            if(sharpflag && num != 0) {
                if(base == 8) {
                    PCHAR('0');
                } else if(base == 16) {
                    PCHAR('0');
                    PCHAR('x');
                }
            }
            if(!ladjust && width && (width -= tmp) > 0)
                while (width--)
                    PCHAR(padc);

            while (*p)
                PCHAR(*p--);

            if(ladjust && width && (width -= tmp) > 0)
                while (width--)
                    PCHAR(padc);

            break;
        default:
            while (percent < fmt)
                PCHAR(*percent++);
            /*
             * Since we ignore an formatting argument it is no
             * longer safe to obey the remaining formatting
             * arguments as the arguments will no longer match
             * the format specs.
             */
            stop = 1;
            break;
        }
    }
#undef PCHAR
}

int printf(const char *fmt, ...)
{
    va_list ap;
    int ret;

    va_start(ap, fmt);
    ret = kvprintf(fmt, putchar, NULL, 10, ap);
    va_end(ap);

    return ret;
}