usr/src/lib/libc/stdio/snprintf.c

/*-
 * Copyright (c) 1990 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Chris Torek.
 *
 * %sccs.include.redist.c%
 */

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)snprintf.c  5.1 (Berkeley) %G%";
#endif /* LIBC_SCCS and not lint */

#include <stdio.h>
#if __STDC__
#include <stdarg.h>
#else
#include <varargs.h>
#endif

#if __STDC__
snprintf(char *str, size_t n, char const *fmt, ...)
#else
snprintf(str, n, fmt, va_alist)
        char *str;
        size_t n;
        char *fmt;
        va_dcl
#endif
{
        int ret;
        va_list ap;
        FILE f;

        if ((int)n < 1)
                return (EOF);
#if __STDC__
        va_start(ap, fmt);
#else
        va_start(ap);
#endif
        f._flags = __SWR | __SSTR;
        f._bf._base = f._p = (unsigned char *)str;
        f._bf._size = f._w = n - 1;
        ret = vfprintf(&f, fmt, ap);
        *f._p = 0;
        va_end(ap);
        return (ret);
}