/*
    Copyright (C) 1995-2025, The AROS Development Team. All rights reserved.

    C99 function printf().
*/

#include <libraries/posixc.h>

#include <stdarg.h>

/*****************************************************************************

    NAME */
#include <stdio.h>

        int printf (

/*  SYNOPSIS */
        const char * format,
        ...)

/*  FUNCTION
        Formats a list of arguments and prints them to standard out.

        The format string is composed of zero or more directives: ordinary
        characters (not %), which are copied unchanged to the output
        stream; and conversion specifications, each of which results in
        fetching zero or more subsequent arguments Each conversion
        specification is introduced by the character %. The arguments must
        correspond properly (after type promotion) with the conversion
        specifier. After the %, the following appear in sequence:

        Zero or more of the following flags:

        # - specifying that the value should be converted to an
            ``alternate form''. For a,A,c, d, i, n, p, s, and u conversions, this
            option has no effect. For o conversions, the precision of the
            number is increased to force the first character of the output
            string to a zero (except if a zero value is printed with an
            explicit precision of zero). For x and X conversions, a non-zero
            result has the string `0x' (or `0X' for X conversions) prepended to
            it. For e, E, f, F,g, and G conversions, the result will always
            contain a decimal point, even if no digits follow it (normally, a
            decimal point appears in the results of those conversions only if a
            digit follows). For g and G conversions, trailing zeros are not
            removed from the result as they would otherwise be.

        0 - specifying zero padding. For all conversions except n, the
            converted value is padded on the left with zeros rather than
            blanks. For f,F conversion, or if a precision is given with a numeric
            conversion (d, i, o,u, i, x, and X), the 0 flag is ignored.

        - - (a negative field width flag) indicates the converted
            value is to be left adjusted on the field boundary. Except for n
            conversions, the converted value is padded on the right with
            blanks, rather than on the left with blanks or zeros. A -
            overrides a 0 if both are given.

          - (a space) specifying that a blank should be left before a
            positive number produced by a signed conversion (d, e, E, f, g, G,
            or i). + specifying that a sign always be placed before a number
            produced by a signed conversion. A + overrides a space if both are
            used.

        ' - specifying that in a numerical argument the output is to
            be grouped if the locale information indicates any. Note that many
            versions of gcc cannot parse this option and will issue a warning.

        An optional decimal digit string specifying a minimum field
        width. If the converted value has fewer characters than the field
        width, it will be padded with spaces on the left (or right, if the
        left-adjustment flag has been given) to fill out the field width.

        An optional precision, in the form of a period (`.') followed
        by an optional digit string. If the digit string is omitted, the
        precision is taken as zero. This gives the minimum number of digits
        to appear for d, i, o, u, x, and X conversions, the number of
        digits to appear after the decimal-point for e, E, and f
        conversions, the maximum number of significant digits for g and G
        conversions, or the maximum number of characters to be printed from
        a string for s conversions.

        The optional character h, specifying that a following d, i,
        o, u, x, or X conversion corresponds to a short int or unsigned
        short int argument, or that a following n conversion corresponds to
        a pointer to a short int argument.

        The optional character l (ell) specifying that a following d,
        i, o, u, x, or X conversion applies to a pointer to a long int or
        unsigned long int argument, or that a following n conversion
        corresponds to a pointer to a long int argument. Linux provides a
        non ANSI compliant use of two l flags as a synonym to q or L. Thus
        ll can be used in combination with float conversions. This usage
        is, however, strongly discouraged.

        The character L specifying that a following e, E,
        f, g, or G conversion corresponds to a long double
        argument, or a following d, i, o, u, x, or X conversion corresponds to a long long argument. Note
        that long long is not specified in ANSI C and
        therefore not portable to all architectures.

        The optional character q. This is equivalent to L. See the
        STANDARDS and BUGS sections for comments on the use of ll, L, and
        q.

        A Z character specifying that the following integer (d, i, o,
        u, i, x, and X), conversion corresponds to a size_t argument.

        A character that specifies the type of conversion to be
        applied.

        A field width or precision, or both, may be indicated by an
        asterisk `*' instead of a digit string. In this case, an int
        argument supplies the field width or precision. A negative field
        width is treated as a left adjustment flag followed by a positive
        field width; a negative precision is treated as though it were
        missing.

        The conversion specifiers and their meanings are:

        diouxX - The int (or appropriate variant) argument is
                 converted to signed decimal (d and i), unsigned octal (o, unsigned
                 decimal (u, or unsigned hexadecimal (x and X) notation. The letters
                 abcdef are used for x conversions; the letters ABCDEF are used for
                 X conversions. The precision, if any, gives the minimum number of
                 digits that must appear; if the converted value requires fewer
                 digits, it is padded on the left with zeros.

        aA - (TODO) The double argument is rounded and converted to the C99
              floating-point number in hexadecimal notation - preserving all
              bits of precision, and presenting them in a robust way.

        eE - The double argument is rounded and converted in the style
             [<->]d.dddedd where there is one digit before the decimal-point
             character and the number of digits after it is equal to the
             precision; if the precision is missing, it is taken as 6; if the
             precision is zero, no decimal-point character appears. An E
             conversion uses the letter E (rather than e) to introduce the
             exponent. The exponent always contains at least two digits; if the
             value is zero, the exponent is 00.

        fF - The double argument is rounded and converted to decimal
            notation in the style [-]ddd.ddd, where the number of digits after
            the decimal-point character is equal to the precision
            specification. If the precision is missing, it is taken as 6; if
            the precision is explicitly zero, no decimal-point character
            appears. If a decimal point appears, at least one digit appears
            before it.

        g - The double argument is converted in style f or e (or E for
            G conversions). The precision specifies the number of significant
            digits. If the precision is missing, 6 digits are given; if the
            precision is zero, it is treated as 1. Style e is used if the
            exponent from its conversion is less than -4 or greater than or
            equal to the precision. Trailing zeros are removed from the
            fractional part of the result; a decimal point appears only if it
            is followed by at least one digit.

        c - The int argument is converted to an unsigned char, and the
            resulting character is written.

        s - The ``char *'' argument is expected to be a pointer to an
            array of character type (pointer to a string). Characters from the
            array are written up to (but not including) a terminating NUL
            character; if a precision is specified, no more than the number
            specified are written. If a precision is given, no null character
            need be present; if the precision is not specified, or is greater
            than the size of the array, the array must contain a terminating
            NUL character.

        p - The ``void *'' pointer argument is printed in hexadecimal
            (as if by %#x or %#lx).

        n - The number of characters written so far is stored into the
            integer indicated by the ``int *'' (or variant) pointer argument.
            No argument is converted.

        % - A `%' is written. No argument is converted. The complete
            conversion specification is `%%'.

        In no case does a non-existent or small field width cause
        truncation of a field; if the result of a conversion is wider than
        the field width, the field is expanded to contain the conversion
        result.

    INPUTS
        format - Format string as described above
        ... - Arguments for the format string

    RESULT
        The number of characters written to stdout or EOF on error.

    NOTES

    EXAMPLE
        To print a date and time in the form `Sunday, July 3,
        10:02', where weekday and month are pointers to strings:

            #include <stdio.h>

            fprintf (stdout, "%s, %s %d, %.2d:%.2d\n",
                    weekday, month, day, hour, min);

        To print to five decimal places:

            #include <math.h>
            #include <stdio.h>

            fprintf (stdout, "pi = %.5f\n", 4 * atan(1.0));

        To allocate a 128 byte string and print into it:

            #include <stdio.h>
            #include <stdlib.h>
            #include <stdarg.h>

            char *newfmt(const char *fmt, ...)
            {
                char *p;
                va_list ap;

                if ((p = malloc(128)) == NULL)
                    return (NULL);

                va_start(ap, fmt);

                (void) vsnprintf(p, 128, fmt, ap);

                va_end(ap);

                return (p);
            }

    BUGS
        All functions are fully ANSI C3.159-1989 conformant, but provide
        the additional flags q, Z and ' as well as an additional behaviour
        of the L and l flags. The latter may be considered to be a bug, as
        it changes the behaviour of flags defined in ANSI C3.159-1989.

        The effect of padding the %p format with zeros (either by the 0
        flag or by specifying a precision), and the benign effect (i.e.,
        none) of the # flag on %n and %p conversions, as well as
        nonsensical combinations such as are not standard; such
        combinations should be avoided.

        Some combinations of flags defined by ANSI C are not making sense
        in ANSI C (e.g. %Ld). While they may have a well-defined behaviour
        on Linux, this need not to be so on other architectures. Therefore
        it usually is better to use flags that are not defined by ANSI C at
        all, i.e. use q instead of L in combination with diouxX conversions
        or ll. The usage of q is not the same as on BSD 4.4, as it may be
        used in float conversions equivalently to L.

        Because sprintf and vsprintf assume an infinitely long string,
        callers must be careful not to overflow the actual space; this is
        often impossible to assure.

    SEE ALSO
        fprintf(), vprintf(), vfprintf(),
        stdc.library/sprintf(), stdc.library/vsprintf(), stdc.library/vsnprintf()

    INTERNALS

******************************************************************************/
{
    struct PosixCBase *PosixCBase = __aros_getbase_PosixCBase();
    int     retval;
    va_list args;

    va_start (args, format);

    retval = vfprintf (PosixCBase->_stdout, format, args);

    va_end (args);

    fflush (PosixCBase->_stdout);

    return retval;
} /* printf */

