glibc/libio/vswprintf.c

143 lines
4.8 KiB
C

/* Copyright (C) 1994,1997,1999,2000,2001,2002 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA.
As a special exception, if you link the code in this file with
files compiled with a GNU compiler to produce an executable,
that does not cause the resulting executable to be covered by
the GNU Lesser General Public License. This exception does not
however invalidate any other reasons why the executable file
might be covered by the GNU Lesser General Public License.
This exception applies to code released by its copyright holders
in files containing the exception. */
#include "libioP.h"
#include "strfile.h"
typedef struct
{
_IO_strfile f;
/* This is used for the characters which do not fit in the buffer
provided by the user. */
wchar_t overflow_buf[64];
} _IO_strnfile;
static wint_t _IO_wstrn_overflow __P ((_IO_FILE *fp, wint_t c));
static wint_t
_IO_wstrn_overflow (fp, c)
_IO_FILE *fp;
wint_t c;
{
/* When we come to here this means the user supplied buffer is
filled. But since we must return the number of characters which
would have been written in total we must provide a buffer for
further use. We can do this by writing on and on in the overflow
buffer in the _IO_strnfile structure. */
_IO_strnfile *snf = (_IO_strnfile *) fp;
if (fp->_wide_data->_IO_buf_base != snf->overflow_buf)
{
INTUSE(_IO_wsetb) (fp, snf->overflow_buf,
snf->overflow_buf + (sizeof (snf->overflow_buf)
/ sizeof (wchar_t)), 0);
fp->_wide_data->_IO_write_base = snf->overflow_buf;
fp->_wide_data->_IO_read_base = snf->overflow_buf;
fp->_wide_data->_IO_read_ptr = snf->overflow_buf;
fp->_wide_data->_IO_read_end = (snf->overflow_buf
+ (sizeof (snf->overflow_buf)
/ sizeof (wchar_t)));
}
fp->_wide_data->_IO_write_ptr = snf->overflow_buf;
fp->_wide_data->_IO_write_end = snf->overflow_buf;
/* Since we are not really interested in storing the characters
which do not fit in the buffer we simply ignore it. */
return c;
}
static struct _IO_jump_t _IO_wstrn_jumps =
{
JUMP_INIT_DUMMY,
JUMP_INIT(finish, _IO_wstr_finish),
JUMP_INIT(overflow, (_IO_overflow_t) _IO_wstrn_overflow),
JUMP_INIT(underflow, (_IO_underflow_t) _IO_wstr_underflow),
JUMP_INIT(uflow, (_IO_underflow_t) INTUSE(_IO_wdefault_uflow)),
JUMP_INIT(pbackfail, (_IO_pbackfail_t) _IO_wstr_pbackfail),
JUMP_INIT(xsputn, INTUSE(_IO_wdefault_xsputn)),
JUMP_INIT(xsgetn, INTUSE(_IO_wdefault_xsgetn)),
JUMP_INIT(seekoff, _IO_wstr_seekoff),
JUMP_INIT(seekpos, _IO_default_seekpos),
JUMP_INIT(setbuf, _IO_default_setbuf),
JUMP_INIT(sync, _IO_default_sync),
JUMP_INIT(doallocate, INTUSE(_IO_wdefault_doallocate)),
JUMP_INIT(read, _IO_default_read),
JUMP_INIT(write, _IO_default_write),
JUMP_INIT(seek, _IO_default_seek),
JUMP_INIT(close, _IO_default_close),
JUMP_INIT(stat, _IO_default_stat),
JUMP_INIT(showmanyc, _IO_default_showmanyc),
JUMP_INIT(imbue, _IO_default_imbue)
};
int
_IO_vswprintf (string, maxlen, format, args)
wchar_t *string;
_IO_size_t maxlen;
const wchar_t *format;
_IO_va_list args;
{
_IO_strnfile sf;
int ret;
struct _IO_wide_data wd;
#ifdef _IO_MTSAFE_IO
sf.f._sbf._f._lock = NULL;
#endif
if (maxlen == 0)
/* Since we have to write at least the terminating L'\0' a buffer
length of zero always makes the function fail. */
return -1;
_IO_no_init (&sf.f._sbf._f, _IO_USER_LOCK, 0, &wd, &_IO_wstrn_jumps);
_IO_fwide (&sf.f._sbf._f, 1);
string[0] = L'\0';
_IO_wstr_init_static (&sf.f._sbf._f, string, maxlen - 1, string);
ret = _IO_vfwprintf ((_IO_FILE *) &sf.f._sbf, format, args);
if (sf.f._sbf._f._wide_data->_IO_buf_base == sf.overflow_buf)
/* ISO C99 requires swprintf/vswprintf to return an error if the
output does not fit int he provided buffer. */
return -1;
/* Terminate the string. */
*sf.f._sbf._f._wide_data->_IO_write_ptr = '\0';
return ret;
}
#ifdef weak_alias
weak_alias (_IO_vswprintf, __vswprintf)
weak_alias (_IO_vswprintf, vswprintf)
#endif