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.