common/stdio/vfwscanf.c

	vfwscanf.c revision da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968
/***********************************************************************
*                                                                      *
*               This software is part of the ast package               *
*           Copyright (c) 1985-2007 AT&T Knowledge Ventures            *
*                      and is licensed under the                       *
*                  Common Public License, Version 1.0                  *
*                      by AT&T Knowledge Ventures                      *
*                                                                      *
*                A copy of the License is available at                 *
*            http://www.opensource.org/licenses/cpl1.0.txt             *
*         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
*                                                                      *
*              Information and Software Systems Research               *
*                            AT&T Research                             *
*                           Florham Park NJ                            *
*                                                                      *
*                 Glenn Fowler <gsf@research.att.com>                  *
*                  David Korn <dgk@research.att.com>                   *
*                   Phong Vo <kpv@research.att.com>                    *
*                                                                      *
***********************************************************************/
#pragma prototyped

#include "stdhdr.h"

typedef struct
{
    Sfdisc_t    sfdisc;     /* sfio discipline      */
    Sfio_t*     f;      /* original wide stream     */
    char        fmt[1];     /* mb fmt           */
} Wide_t;

/*
 * wide exception handler
 * free on close
 */

static int
wideexcept(Sfio_t* f, int op, void* val, Sfdisc_t* dp)
{
    if (sffileno(f) >= 0)
        return -1;
    switch (op)
    {
    case SF_ATEXIT:
        sfdisc(f, SF_POPDISC);
        break;
    case SF_CLOSING:
    case SF_DPOP:
    case SF_FINAL:
        if (op != SF_CLOSING)
            free(dp);
        break;
    }
    return 0;
}

/*
 * sfio wide discipline read
 * 1 wchar_t at a time
 * go pure multibyte for best performance
 */

static ssize_t
wideread(Sfio_t* f, Void_t* buf, size_t size, Sfdisc_t* dp)
{
    register Wide_t*    w = (Wide_t*)dp;
    wchar_t         wuf[2];

#if 0
    if (sfread(w->f, wuf, sizeof(wuf[0])) != sizeof(wuf[0]))
        return -1;
    wuf[1] = 0;
    return wcstombs(buf, wuf, size);
#else
    ssize_t r;

    r = sfread(w->f, wuf, sizeof(wuf[0]));
    if (r != sizeof(wuf[0]))
        return -1;
    wuf[1] = 0;
    r = wcstombs(buf, wuf, size);
    return r;
#endif
}

int
vfwscanf(Sfio_t* f, const wchar_t* fmt, va_list args)
{
    size_t  n;
    int v;
    Sfio_t* t;
    Wide_t* w;
    char    buf[1024];

    STDIO_INT(f, "vfwscanf", int, (Sfio_t*, const wchar_t*, va_list), (f, fmt, args))

    FWIDE(f, WEOF);
    n = wcstombs(NiL, fmt, 0);
    if (w = newof(0, Wide_t, 1, n))
    {
        if (t = sfnew(NiL, buf, sizeof(buf), OPEN_MAX+1, SF_READ))
        {
            w->sfdisc.exceptf = wideexcept;
            w->sfdisc.readf = wideread;
            w->f = f;
            if (sfdisc(t, &w->sfdisc) == &w->sfdisc)
            {
                wcstombs(w->fmt, fmt, n + 1);
                v = sfvscanf(t, w->fmt, args);
            }
            else
            {
                free(w);
                v = -1;
            }
            sfsetfd(t, -1);
            sfclose(t);
        }
        else
        {
            free(w);
            v = -1;
        }
    }
    else
        v = -1;
    return v;
}