NAME
    RawDoFmt -- format data into a character stream.

SYNOPSIS
    NextData = RawDoFmt(FormatString, DataStream, PutChProc, PutChData);
   d0                  a0            a1          a2         a3

    APTR RawDoFmt(STRPTR,APTR,void (*)(),APTR);

FUNCTION
    perform "C"-language-like formatting of a data stream, outputting
    the result a character at a time.  Where % formatting commands are
    found in the FormatString, they will be replaced with the
    corresponding element in the DataStream.  %% must be used in the
    string if a % is desired in the output.

    Under V36, RawDoFmt() returns a pointer to the end of the DataStream
    (The next argument that would have been processed).  This allows
    multiple formatting passes to be made using the same data.

INPUTS
    FormatString - a "C"-language-like NULL terminated format string,
    with the following supported % options:

     %[flags][width.limit][length]type

    flags  - only one allowed. '-' specifies left justification.
    width  - field width.  If the first character is a '0', the
             field will be padded with leading 0's.
      .    - must follow the field width, if specified
    limit  - maximum number of characters to output from a string.
             (only valid for %s).
    length - size of input data defaults to WORD for types d, x,
             and c, 'l' changes this to long (32-bit).
    type   - supported types are:
                    b - BSTR, data is 32-bit BPTR to byte count followed
                        by a byte string, or NULL terminated byte string.
                        A NULL BPTR is treated as an empty string.
                        (Added in V36 exec)
                    d - decimal
                    u - unsigned decimal (Added in V37 exec)
                    x - hexadecimal
                    s - string, a 32-bit pointer to a NULL terminated
                        byte string.  In V36, a NULL pointer is treated
                        as an empty string
                    c - character

    DataStream - a stream of data that is interpreted according to
             the format string.  Often this is a pointer into
             the task's stack.
    PutChProc  - the procedure to call with each character to be
             output, called as:

    PutChProc(Char,  PutChData);
              D0-0:8 A3

            the procedure is called with a NULL Char at the end of
            the format string.

    PutChData - a value that is passed through to the PutChProc
            procedure.  This is untouched by RawDoFmt, and may be
            modified by the PutChProc.

EXAMPLE
    ;
    ; Simple version of the C "sprintf" function.  Assumes C-style
    ; stack-based function conventions.
    ;
    ;   long eyecount;
    ;   eyecount=2;
    ;   sprintf(string,"%s have %ld eyes.","Fish",eyecount);
    ;
    ; would produce "Fish have 2 eyes." in the string buffer.
    ;
            XDEF _sprintf
            XREF _AbsExecBase
            XREF _LVORawDoFmt
    _sprintf:       ; ( ostring, format, {values} )
            movem.l a2/a3/a6,-(sp)

            move.l  4*4(sp),a3       ;Get the output string pointer
            move.l  5*4(sp),a0       ;Get the FormatString pointer
            lea.l   6*4(sp),a1       ;Get the pointer to the DataStream
            lea.l   stuffChar(pc),a2
            move.l  _AbsExecBase,a6
            jsr     _LVORawDoFmt(a6)

            movem.l (sp)+,a2/a3/a6
            rts

    ;------ PutChProc function used by RawDoFmt -----------
    stuffChar:
            move.b  d0,(a3)+        ;Put data to output string
            rts

WARNING
    This Amiga ROM function formats word values in the data stream.  If
    your compiler defaults to longs, you must add an "l" to your
    % specifications.  This can get strange for characters, which might
    look like "%lc".

    The result of RawDoFmt() is *ONLY* valid in V36 and later releases
    of EXEC.  Pre-V36 versions of EXEC have "random" return values.

SEE ALSO
    Documentation on the C language "printf" call in any C language
    reference book.