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/**

    @file printf-stdarg.c

    @brief Replacement for printf. Limited functionality (e.g. no float format).

    This code relies on external functions getchar and putchar.

*/

/*

        Copyright 2001, 2002 Georges Menie (www.menie.org)

        stdarg version contributed by Christian Ettinger

    This program is free software; you can redistribute it and/or modify

    it under the terms of the GNU Lesser General Public License as published by

    the Free Software Foundation; either version 2 of the License, or

    (at your option) any later version.

    This program is distributed in the hope that it will be useful,

    but WITHOUT ANY WARRANTY; without even the implied warranty of

    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

    GNU Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public License

    along with this program; if not, write to the Free Software

    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

*/

/*

        putchar is the only external dependency for this file,

        if you have a working putchar, leave it commented out.

        If not, uncomment the define below and

        replace outbyte(c) by your own function call.

#define putchar(c) outbyte(c)

*/

#include <stdarg.h>

/** Prints character to string buffer.

    Used by printf, not to be used directly.*/

static void printchar(char **str, int c)

{

        extern int putchar(int c);

        if (str) {

                **str = c;

                ++(*str);

        }

        else (void)putchar(c);

}

#define PAD_RIGHT (1)   /**<  */

#define PAD_ZERO (2)    /**< */

/** Prints formatted string to string buffer.

    Used by printf, not to be used directly.*/

static int prints(char **out, const char *string, int width, int pad)

{

        register int pc = 0, padchar = ' ';

        if (width > 0) {

                register int len = 0;

                register const char *ptr;

                for (ptr = string; *ptr; ++ptr) ++len;

                if (len >= width) width = 0;

                else width -= len;

                if (pad & PAD_ZERO) padchar = '0';

        }

        if (!(pad & PAD_RIGHT)) {

                for ( ; width > 0; --width) {

                        printchar (out, padchar);

                        ++pc;

                }

        }

        for ( ; *string ; ++string) {

                printchar (out, *string);

                ++pc;

        }

        for ( ; width > 0; --width) {

                printchar (out, padchar);

                ++pc;

        }

        return pc;

}

/** Temporary buffer used to print numbers to */

/* the following should be enough for 32 bit int */

#define PRINT_BUF_LEN 12

/** Prints formatted integer to string buffer.

    Used by printf, not to be used directly.*/

static int printi(char **out, int i, int b, int sg, int width, int pad, int letbase)

{

        char print_buf[PRINT_BUF_LEN];

        register char *s;

        register int t, neg = 0, pc = 0;

        register unsigned int u = i;

        if (i == 0) {

                print_buf[0] = '0';

                print_buf[1] = '\0';

                return prints (out, print_buf, width, pad);

        }

        if (sg && b == 10 && i < 0) {

                neg = 1;

                u = -i;

        }

        s = print_buf + PRINT_BUF_LEN-1;

        *s = '\0';

        while (u) {

                t = u % b;

                if( t >= 10 )

                        t += letbase - '0' - 10;

                *--s = t + '0';

                u /= b;

        }

        if (neg) {

                if( width && (pad & PAD_ZERO) ) {

                        printchar (out, '-');

                        ++pc;

                        --width;

                }

                else {

                        *--s = '-';

                }

        }

        return pc + prints (out, s, width, pad);

}

/** Main print function; parses format string and calls aux functions.

    Used by printf, not to be used directly.*/

static int print( char **out, const char *format, va_list args )

{

        register int width, pad;

        register int pc = 0;

        char scr[2];

        for (; *format != 0; ++format) {

                if (*format == '%') {

                        ++format;

                        width = pad = 0;

                        if (*format == '\0') break;

                        if (*format == '%') goto out;

                        if (*format == '-') {

                                ++format;

                                pad = PAD_RIGHT;

                        }

                        while (*format == '0') {

                                ++format;

                                pad |= PAD_ZERO;

                        }

                        for ( ; *format >= '0' && *format <= '9'; ++format) {

                                width *= 10;

                                width += *format - '0';

                        }

                        if( *format == 's' ) {

                                register char *s = (char *)va_arg( args, int );

                                pc += prints (out, s?s:"(null)", width, pad);

                                continue;

                        }

                        if( *format == 'd' ) {

                                pc += printi (out, va_arg( args, int ), 10, 1, width, pad, 'a');

                                continue;

                        }

                        if( *format == 'x' ) {

                                pc += printi (out, va_arg( args, int ), 16, 0, width, pad, 'a');

                                continue;

                        }

                        if( *format == 'X' ) {

                                pc += printi (out, va_arg( args, int ), 16, 0, width, pad, 'A');

                                continue;

                        }

                        if( *format == 'u' ) {

                                pc += printi (out, va_arg( args, int ), 10, 0, width, pad, 'a');

                                continue;

                        }

                        if( *format == 'c' ) {

                                /* char are converted to int then pushed on the stack */

                                scr[0] = (char)va_arg( args, int );

                                scr[1] = '\0';

                                pc += prints (out, scr, width, pad);

                                continue;

                        }

                }

                else {

                out:

                        printchar (out, *format);

                        ++pc;

                }

        }

        if (out) **out = '\0';

        va_end( args );

        return pc;

}

/** Replacement for standard printf. */

int printf(const char *format, ...)

{

        va_list args;

        va_start( args, format );

        return print( 0, format, args );

}

/** Replacement for standard sprintf. */

int sprintf(char *out, const char *format, ...)

{

        va_list args;

        va_start( args, format );

        return print( &out, format, args );

}

/**Replacement for standard snprintf.  */

int snprintf( char *buf, unsigned int count, const char *format, ... )

{

        va_list args;

        ( void ) count;

        va_start( args, format );

        return print( &buf, format, args );

}

#ifdef TEST_PRINTF

int main(void)

{

#if 1

        char *ptr = "Hello world!";

        char *np = 0;

        int i = 5;

        unsigned int bs = sizeof(int)*8;

        int mi;

        char buf[80];

        mi = (1 << (bs-1)) + 1;

        printf("%s\n", ptr);

        printf("printf test\n");

        printf("%s is null pointer\n", np);

        printf("%d = 5\n", i);

        printf("%d = - max int\n", mi);

        printf("char %c = 'a'\n", 'a');

        printf("hex %x = ff\n", 0xff);

        printf("hex %02x = 00\n", 0);

        printf("signed %d = unsigned %u = hex %x\n", -3, -3, -3);

        printf("%d %s(s)%", 0, "message");

        printf("\n");

        printf("%d %s(s) with %%\n", 0, "message");

        sprintf(buf, "justif: \"%-10s\"\n", "left"); printf("%s", buf);

        sprintf(buf, "justif: \"%10s\"\n", "right"); printf("%s", buf);

        sprintf(buf, " 3: %04d zero padded\n", 3); printf("%s", buf);

        sprintf(buf, " 3: %-4d left justif.\n", 3); printf("%s", buf);

        sprintf(buf, " 3: %4d right justif.\n", 3); printf("%s", buf);

        sprintf(buf, "-3: %04d zero padded\n", -3); printf("%s", buf);

        sprintf(buf, "-3: %-4d left justif.\n", -3); printf("%s", buf);

        sprintf(buf, "-3: %4d right justif.\n", -3); printf("%s", buf);

#endif

        return 0;

}

/*

 * if you compile this file with

 *   gcc -Wall $(YOUR_C_OPTIONS) -DTEST_PRINTF -c printf.c

 * you will get a normal warning:

 *   printf.c:214: warning: spurious trailing `%' in format

 * this line is testing an invalid % at the end of the format string.

 *

 * this should display (on 32bit int machine) :

 *

 * Hello world!

 * printf test

 * (null) is null pointer

 * 5 = 5

 * -2147483647 = - max int

 * char a = 'a'

 * hex ff = ff

 * hex 00 = 00

 * signed -3 = unsigned 4294967293 = hex fffffffd

 * 0 message(s)

 * 0 message(s) with %

 * justif: "left      "

 * justif: "     right"

 *  3: 0003 zero padded

 *  3: 3    left justif.

 *  3:    3 right justif.

 * -3: -003 zero padded

 * -3: -3   left justif.

 * -3:   -3 right justif.

 */

#endif

/** Stub function, only used to deceive the linker. */

/* To keep linker happy. */

int     write( int i, char* c, int n)

{

        return 0;

}