/*      $NetBSD: printf.c,v 1.59 2024/11/24 12:33:00 kre Exp $  */

/*
 * Copyright (c) 1989, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * 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.
 * 3. 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.
 */

#include <sys/cdefs.h>
#ifndef lint
#if !defined(BUILTIN) && !defined(SHELL)
__COPYRIGHT("@(#) Copyright (c) 1989, 1993\
 The Regents of the University of California.  All rights reserved.");
#endif
#endif

#ifndef lint
#if 0
static char sccsid[] = "@(#)printf.c    8.2 (Berkeley) 3/22/95";
#else
__RCSID("$NetBSD: printf.c,v 1.59 2024/11/24 12:33:00 kre Exp $");
#endif
#endif /* not lint */

#include <sys/types.h>

#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <inttypes.h>
#include <limits.h>
#include <locale.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#ifdef __GNUC__
#define ESCAPE '\e'
#else
#define ESCAPE 033
#endif

static void      conv_escape_str(char *, void (*)(int), int);
static char     *conv_escape(char *, char *, int);
static char     *conv_expand(const char *);
static wchar_t   getchr(void);
static long double getdouble(void);
static int       getwidth(void);
static intmax_t  getintmax(void);
static char     *getstr(void);
static char     *mklong(const char *, char, char);
static intmax_t  wide_char(const char *, int);
static void      check_conversion(const char *, const char *);
static void      usage(void);

static void     b_count(int);
static void     b_output(int);
static size_t   b_length;
static char     *b_fmt;

static int      rval;
static char  ** gargv, ** firstarg;
static int      long_double;

#define ARGNUM  ((int)(gargv - firstarg))

#ifdef BUILTIN          /* csh builtin */
#define main progprintf
#endif

#ifdef SHELL            /* sh (aka ash) builtin */
#define main printfcmd
#include "../../bin/sh/bltin/bltin.h"
#endif /* SHELL */

#define PF(f, func) { \
        if (fieldwidth != -1) { \
                if (precision != -1) \
                        error = printf(f, fieldwidth, precision, func); \
                else \
                        error = printf(f, fieldwidth, func); \
        } else if (precision != -1) \
                error = printf(f, precision, func); \
        else \
                error = printf(f, func); \
}

#define APF(cpp, f, func) { \
        if (fieldwidth != -1) { \
                if (precision != -1) \
                        error = asprintf(cpp, f, fieldwidth, precision, func); \
                else \
                        error = asprintf(cpp, f, fieldwidth, func); \
        } else if (precision != -1) \
                error = asprintf(cpp, f, precision, func); \
        else \
                error = asprintf(cpp, f, func); \
}

#define isodigit(c)     ((c) >= '0' && (c) <= '7')
#define octtobin(c)     ((c) - '0')
#define check(c, a)     (c) >= (a) && (c) <= (a) + 5 ? (c) - (a) + 10
#define hextobin(c)     (check(c, 'a') : check(c, 'A') : (c) - '0')

#ifdef main
int main(int, char *[]);
#endif

int
main(int argc, char *argv[])
{
        char *fmt, *start;
        int fieldwidth, precision;
        char nextch;
        char *format;
        char ch;
        int error;

#if !defined(SHELL) && !defined(BUILTIN)
        (void)setlocale (LC_ALL, "");
#endif

        rval = 0;       /* clear for builtin versions (avoid holdover) */
        long_double = 0;
        clearerr(stdout);       /* for the builtin version */

        if (argc > 2 && strchr(argv[1], '%') == NULL) {
                int o;

                /*
                 * We only do this for argc > 2, as:
                 *
                 * for argc <= 1
                 *      at best we have a bare "printf" so there cannot be
                 *      any options, thus getopts() would be a waste of time.
                 *      The usage() below is assured.
                 *
                 * for argc == 2
                 *      There is only one arg (argv[1]) which logically must
                 *      be intended to be the (required) format string for
                 *      printf, without which we can do nothing so rather
                 *      than usage() if it happens to start with a '-' we
                 *      just avoid getopts() and treat it as a format string.
                 *
                 * Then, for argc > 2, we also skip this if there is a '%'
                 * anywhere in argv[1] as it is likely that would be intended
                 * to be the format string, rather than options, even if it
                 * starts with a '-' so we skip getopts() in that case as well.
                 *
                 * Note that this would fail should there ever be an option
                 * which takes an arbitrary string value, which could be given
                 * as -Oabc%def so should that ever become possible, remove
                 * the strchr() test above.
                 */

                while ((o = getopt(argc, argv, "L")) != -1) {
                        switch (o) {
                        case 'L':
                                long_double = 1;
                                break;
                        case '?':
                        default:
                                usage();
                                return 1;
                        }
                }
                argc -= optind;
                argv += optind;
        } else {
                argc -= 1;      /* drop argv[0] (the program name) */
                argv += 1;
        }

        if (argc < 1) {         /* Nothing left at all? */
                usage();
                return 1;
        }

        format = *argv;         /* First remaining arg is the format string */
        firstarg = gargv = ++argv; /* remaining args are for that to consume */

#define SKIP1   "#-+ 0'"
#define SKIP2   "0123456789"
        do {
                /*
                 * Basic algorithm is to scan the format string for conversion
                 * specifications -- once one is found, find out if the field
                 * width or precision is a '*'; if it is, gather up value.
                 * Note, format strings are reused as necessary to use up the
                 * provided arguments, arguments of zero/null string are
                 * provided to use up the format string.
                 */

                /* find next format specification */
                for (fmt = format; (ch = *fmt++) != '\0';) {
                        if (ch == '\\') {
                                char c_ch;

                                fmt = conv_escape(fmt, &c_ch, 0);
                                putchar(c_ch);
                                continue;
                        }
                        if (ch != '%' || (*fmt == '%' && ++fmt)) {
                                (void)putchar(ch);
                                continue;
                        }

                        /*
                         * Ok - we've found a format specification,
                         * Save its address for a later printf().
                         */
                        start = fmt - 1;

                        /* skip to field width */
                        fmt += strspn(fmt, SKIP1);
                        if (*fmt == '*') {
                                fmt++;
                                fieldwidth = getwidth();
                        } else {
                                fieldwidth = -1;

                                /* skip to possible '.' for precision */
                                fmt += strspn(fmt, SKIP2);
                        }

                        if (*fmt == '.') {
                                 /* get following precision */
                                fmt++;
                                if (*fmt == '*') {
                                        fmt++;
                                        precision = getwidth();
                                } else {
                                        precision = -1;
                                        fmt += strspn(fmt, SKIP2);
                                }
                        } else
                                precision = -1;

                        ch = *fmt;
                        if (!ch) {
                                warnx("%s: missing format character", start);
                                return 1;
                        }

                        /*
                         * null terminate format string to we can use it
                         * as an argument to printf.
                         */
                        nextch = fmt[1];
                        fmt[1] = 0;

                        switch (ch) {

                        case 'B': {
                                const char *p = conv_expand(getstr());

                                if (p == NULL)
                                        goto out;
                                *fmt = 's';
                                PF(start, p);
                                if (error < 0)
                                        goto out;
                                break;
                        }
                        case 'b': {
                                /*
                                 * There has to be a better way to do this,
                                 * but the string we generate might have
                                 * embedded nulls
                                 */
                                static char *a, *t;
                                char *cp = getstr();

                                /* Free on entry in case shell longjumped out */
                                if (a != NULL)
                                        free(a);
                                a = NULL;
                                if (t != NULL)
                                        free(t);
                                t = NULL;

                                /* Count number of bytes we want to output */
                                b_length = 0;
                                conv_escape_str(cp, b_count, 0);
                                t = malloc(b_length + 1);
                                if (t == NULL)
                                        goto out;
                                (void)memset(t, 'x', b_length);
                                t[b_length] = 0;

                                /* Get printf to calculate the lengths */
                                *fmt = 's';
                                APF(&a, start, t);
                                if (error == -1)
                                        goto out;
                                b_fmt = a;

                                /* Output leading spaces and data bytes */
                                conv_escape_str(cp, b_output, 1);

                                /* Add any trailing spaces */
                                printf("%s", b_fmt);
                                break;
                        }
                        case 'C': {
                                wchar_t p = (wchar_t)getintmax();
                                char *f = mklong(start, 'c', 'l');

                                PF(f, p);
                                if (error < 0)
                                        goto out;
                                break;
                        }
                        case 'c': {
                                wchar_t p = getchr();
                                char *f = mklong(start, ch, 'l');

                                PF(f, p);
                                if (error < 0)
                                        goto out;
                                break;
                        }
                        case 's': {
                                char *p = getstr();

                                PF(start, p);
                                if (error < 0)
                                        goto out;
                                break;
                        }
                        case 'd':
                        case 'i': {
                                intmax_t p = getintmax();
                                char *f = mklong(start, ch, 'j');

                                PF(f, p);
                                if (error < 0)
                                        goto out;
                                break;
                        }
                        case 'o':
                        case 'u':
                        case 'x':
                        case 'X': {
                                uintmax_t p = (uintmax_t)getintmax();
                                char *f = mklong(start, ch, 'j');

                                PF(f, p);
                                if (error < 0)
                                        goto out;
                                break;
                        }
                        case 'a':
                        case 'A':
                        case 'e':
                        case 'E':
                        case 'f':
                        case 'F':
                        case 'g':
                        case 'G': {
                                long double p = getdouble();

                                if (long_double) {
                                        char * f = mklong(start, ch, 'L');
                                        PF(f, p);
                                } else {
                                        double pp = (double)p;
                                        PF(start, pp);
                                }
                                if (error < 0)
                                        goto out;
                                break;
                        }
                        case '%':
                                /* Don't ask, but this is useful ... */
                                if (fieldwidth == 'N' && precision == 'B')
                                        return 0;
                                /* FALLTHROUGH */
                        default:
                                warnx("%s: invalid directive", start);
                                return 1;
                        }
                        *fmt++ = ch;
                        *fmt = nextch;
                        /* escape if a \c was encountered */
                        if (rval & 0x100)
                                goto done;
                }
        } while (gargv != argv && *gargv);

  done:;
        (void)fflush(stdout);
        if (ferror(stdout)) {
                clearerr(stdout);
                err(1, "write error");
        }
        return rval & ~0x100;
  out:;
        warn("print failed");
        return 1;
}

/* helper functions for conv_escape_str */

static void
/*ARGSUSED*/
b_count(int ch)
{
        b_length++;
}

/* Output one converted character for every 'x' in the 'format' */

static void
b_output(int ch)
{
        for (;;) {
                switch (*b_fmt++) {
                case 0:
                        b_fmt--;
                        return;
                case ' ':
                        putchar(' ');
                        break;
                default:
                        putchar(ch);
                        return;
                }
        }
}


/*
 * Print SysV echo(1) style escape string
 *      Halts processing string if a \c escape is encountered.
 */
static void
conv_escape_str(char *str, void (*do_putchar)(int), int quiet)
{
        int value;
        int ch;
        char c;

        while ((ch = *str++) != '\0') {
                if (ch != '\\') {
                        do_putchar(ch);
                        continue;
                }

                ch = *str++;
                if (ch == 'c') {
                        /* \c as in SYSV echo - abort all processing.... */
                        rval |= 0x100;
                        break;
                }

                /*
                 * %b string octal constants are not like those in C.
                 * They start with a \0, and are followed by 0, 1, 2,
                 * or 3 octal digits.
                 */
                if (ch == '0') {
                        int octnum = 0, i;

                        for (i = 0; i < 3; i++) {
                                if (!isdigit((unsigned char)*str) || *str > '7')
                                        break;
                                octnum = (octnum << 3) | (*str++ - '0');
                        }
                        do_putchar(octnum);
                        continue;
                }

                /* \[M][^|-]C as defined by vis(3) */
                if (ch == 'M' && *str == '-') {
                        do_putchar(0200 | str[1]);
                        str += 2;
                        continue;
                }
                if (ch == 'M' && *str == '^') {
                        str++;
                        value = 0200;
                        ch = '^';
                } else
                        value = 0;
                if (ch == '^') {
                        ch = *str++;
                        if (ch == '?')
                                value |= 0177;
                        else
                                value |= ch & 037;
                        do_putchar(value);
                        continue;
                }

                /* Finally test for sequences valid in the format string */
                str = conv_escape(str - 1, &c, quiet);
                do_putchar(c);
        }
}

/*
 * Print "standard" escape characters
 */
static char *
conv_escape(char *str, char *conv_ch, int quiet)
{
        int value = 0;
        char ch, *begin;
        int c;

        ch = *str++;

        switch (ch) {
        case '\0':
                if (!quiet)
                        warnx("incomplete escape sequence");
                rval = 1;
                value = '\\';
                --str;
                break;

        case '0': case '1': case '2': case '3':
        case '4': case '5': case '6': case '7':
                str--;
                for (c = 3; c-- && isodigit(*str); str++) {
                        value <<= 3;
                        value += octtobin(*str);
                }
                break;

        case 'x':
                /*
                 * Hexadecimal character constants are not required to be
                 * supported (by SuS v1) because there is no consistent
                 * way to detect the end of the constant.
                 * Supporting 2 byte constants is a compromise.
                 */
                begin = str;
                for (c = 2; c-- && isxdigit((unsigned char)*str); str++) {
                        value <<= 4;
                        value += hextobin(*str);
                }
                if (str == begin) {
                        if (!quiet)
                                warnx("\\x%s: missing hexadecimal number "
                                    "in escape", begin);
                        rval = 1;
                }
                break;

        case '\\':      value = '\\';   break;  /* backslash */
        case '\'':      value = '\'';   break;  /* single quote */
        case '"':       value = '"';    break;  /* double quote */
        case 'a':       value = '\a';   break;  /* alert */
        case 'b':       value = '\b';   break;  /* backspace */
        case 'e':       value = ESCAPE; break;  /* escape */
        case 'E':       value = ESCAPE; break;  /* escape */
        case 'f':       value = '\f';   break;  /* form-feed */
        case 'n':       value = '\n';   break;  /* newline */
        case 'r':       value = '\r';   break;  /* carriage-return */
        case 't':       value = '\t';   break;  /* tab */
        case 'v':       value = '\v';   break;  /* vertical-tab */

        default:
                if (!quiet)
                        warnx("unknown escape sequence `\\%c'", ch);
                rval = 1;
                value = ch;
                break;
        }

        *conv_ch = (char)value;
        return str;
}

/* expand a string so that everything is printable */

static char *
conv_expand(const char *str)
{
        static char *conv_str;
        char *cp;
        char ch;

        if (conv_str)
                free(conv_str);
        /* get a buffer that is definitely large enough.... */
        conv_str = malloc(4 * strlen(str) + 1);
        if (!conv_str)
                return NULL;
        cp = conv_str;

        while ((ch = *(const char *)str++) != '\0') {
                switch (ch) {
                /* Use C escapes for expected control characters */
                case '\\':      ch = '\\';      break;  /* backslash */
                case '\'':      ch = '\'';      break;  /* single quote */
                case '"':       ch = '"';       break;  /* double quote */
                case '\a':      ch = 'a';       break;  /* alert */
                case '\b':      ch = 'b';       break;  /* backspace */
                case ESCAPE:    ch = 'e';       break;  /* escape */
                case '\f':      ch = 'f';       break;  /* form-feed */
                case '\n':      ch = 'n';       break;  /* newline */
                case '\r':      ch = 'r';       break;  /* carriage-return */
                case '\t':      ch = 't';       break;  /* tab */
                case '\v':      ch = 'v';       break;  /* vertical-tab */
                default:
                        /* Copy anything printable */
                        if (isprint((unsigned char)ch)) {
                                *cp++ = ch;
                                continue;
                        }
                        /* Use vis(3) encodings for the rest */
                        *cp++ = '\\';
                        if (ch & 0200) {
                                *cp++ = 'M';
                                ch &= (char)~0200;
                        }
                        if (ch == 0177) {
                                *cp++ = '^';
                                *cp++ = '?';
                                continue;
                        }
                        if (ch < 040) {
                                *cp++ = '^';
                                *cp++ = ch | 0100;
                                continue;
                        }
                        *cp++ = '-';
                        *cp++ = ch;
                        continue;
                }
                *cp++ = '\\';
                *cp++ = ch;
        }

        *cp = 0;
        return conv_str;
}

static char *
mklong(const char *str, char ch, char longer)
{
        static char copy[64];
        size_t len;     

        len = strlen(str) + 2;
        if (len > sizeof copy) {
                warnx("format \"%s\" too complex", str);
                len = 4;
                rval = 1;
        }
        (void)memmove(copy, str, len - 3);
        copy[len - 3] = longer;
        copy[len - 2] = ch;
        copy[len - 1] = '\0';
        return copy;    
}

static wchar_t
getchr(void)
{
        if (!*gargv)
                return 0;
        return (wchar_t)wide_char(*gargv++, 0);
}

static char *
getstr(void)
{
        static char empty[] = "";

        if (!*gargv)
                return empty;
        return *gargv++;
}

static int
getwidth(void)
{
        unsigned long val;
        char *s, *ep;

        s = *gargv;
        if (s == NULL)
                return 0;
        gargv++;

        errno = 0;
        val = strtoul(s, &ep, 0);
        if (!isdigit(*(unsigned char *)s)) {
                warnx("Arg %d: '%s' value for '*' width/precision"
                    " must be an unsigned integer", ARGNUM, s);
                rval = 1;
                val = 0;
        } else
                check_conversion(s, ep);

        /* Arbitrarily 'restrict' field widths to 1Mbyte */
        if (val > 1 << 20) {
                warnx("Arg %d: %s: invalid field width/precision", ARGNUM, s);
                rval = 1;
                return 0;
        }

        return (int)val;
}

static intmax_t
getintmax(void)
{
        intmax_t val;
        char *cp, *ep;

        cp = *gargv;
        if (cp == NULL)
                return 0;
        gargv++;

        if (*cp == '\"' || *cp == '\'')
                return wide_char(cp, 1);

        errno = 0;
        val = strtoimax(cp, &ep, 0);
        if (*cp != '+' && *cp != '-' && !isdigit(*(unsigned char *)cp)) {
                warnx("Arg %d: '%s' numeric value required", ARGNUM, cp);
                rval = 1;
        } else
                check_conversion(cp, ep);
        return val;
}

static long double
getdouble(void)
{
        long double val;
        char *ep;

        if (!*gargv)
                return 0.0;

        /* This is a NetBSD extension, not required by POSIX (it is useless) */
        if (*(ep = *gargv) == '\"' || *ep == '\'')
                return (long double)wide_char(ep, 1);

        errno = 0;
        val = strtold(*gargv, &ep);
        check_conversion(*gargv++, ep);
        return val;
}

/*
 * Fetch a wide character from the string given
 *
 * if all that character must consume the entire string
 * after an initial leading byte (ascii char) is ignored,
 * (used for parsing intger args using the 'X syntax)
 *
 * if !all then there is no requirement that the whole
 * string be consumed (remaining characters are just ignored)
 * but the character is to start at *p.
 * (used for fetching the first chartacter of a string arg for %c)
 */
static intmax_t
wide_char(const char *p, int all)
{
        wchar_t wch;
        size_t len;
        int n;

        (void)mbtowc(NULL, NULL, 0);
        n = mbtowc(&wch, p + all, (len = strlen(p + all)) + 1);
        if (n < 0) {
                warn("Arg %d: %s", ARGNUM, p);
                rval = 1;
        } else if (all && (size_t)n != len) {
                warnx("Arg %d: %s: not completely converted",
                    ARGNUM, p);
                rval = 1;
        }

        return (intmax_t) wch;
}

static void
check_conversion(const char *s, const char *ep)
{
        if (!*s) {
                warnx("Arg %d: unexpected empty value ('')", ARGNUM);
                rval = 1;
                return;
        }

        if (*ep) {
                if (ep == s)
                        warnx("Arg %d: %s: numeric value expected", ARGNUM, s);
                else
                        warnx("Arg %d: %s: not completely converted",
                            ARGNUM, s);
                rval = 1;
                return;
        }

        if (errno == ERANGE) {
                warnx("Arg %d: %s: %s", ARGNUM, s, strerror(ERANGE));
                rval = 1;
        }
}

static void
usage(void)
{
        (void)fprintf(stderr,
            "Usage: %s [-L] format [arg ...]\n", getprogname());
}