vfprintf.c

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#include <stdio.h>
#include <stdlib.h>
 
#include "common/print.h"
#include "user/common/file.h"
#include "user/common/syscalls.h"
 
int vfprintf(FILE* _RESTRICT stream, const char* _RESTRICT format, va_list arg)
{
    _format_ctx_t ctx;
    ctx.base = 0;
    ctx.flags = 0;
    ctx.maxChars = SIZE_MAX;
    ctx.totalChars = 0;
    ctx.currentChars = 0;
    ctx.buffer = NULL;
    ctx.width = 0;
    ctx.precision = EOF;
    ctx.stream = stream;
 
    mtx_lock(&stream->mtx);
 
    if (_file_prepare_write(stream) == ERR)
    {
        mtx_unlock(&stream->mtx);
        return EOF;
    }
 
    va_copy(ctx.arg, arg);
 
    while (*format != '\0')
    {
        const char* rc;
 
        if ((*format != '%') || ((rc = _print(format, &ctx)) == format))
        {
            /* No conversion specifier, print verbatim */
            stream->buf[stream->bufIndex++] = *format;
 
            if ((stream->bufIndex == stream->bufSize) || ((stream->flags & _FILE_LINE_BUFFERED) && (*format == '\n')) ||
                (stream->flags & _FILE_UNBUFFERED))
            {
                if (_file_flush_buffer(stream) == ERR)
                {
                    mtx_unlock(&stream->mtx);
                    return EOF;
                }
            }
 
            ++format;
            ctx.totalChars++;
        }
        else
        {
            /* Continue parsing after conversion specifier */
            format = rc;
        }
    }
 
    va_end(ctx.arg);
    mtx_unlock(&stream->mtx);
    return ctx.totalChars;
}