libsyscall/mach/fprintf_stderr.c

   1 /*
   2  * Copyright (c) 2003-2010 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28 /*
  29  * @OSF_FREE_COPYRIGHT@
  30  *
  31  */
  32
  33 #include <mach/mach.h>
  34 #include <mach/mach_init.h>
  35 #include <stdarg.h>
  36 #include "string.h"
  37
  38 int (*vprintf_stderr_func)(const char *format, va_list ap);
  39
  40 #define __STDERR_FILENO 2
  41 int write(int fd, const char* cbuf, int nbyte);
  42
  43 /* This function allows the writing of a mach error message to an
  44  * application-controllable output method, the default being to
  45  * use printf if no other method is specified by the application.
  46  *
  47  * To override, set the global function pointer vprintf_stderr to
  48  * a function which takes the same parameters as vprintf.
  49  */
  50
  51 __private_extern__ int
  52 fprintf_stderr(const char *format, ...)
  53 {
  54         va_list args;
  55         int retval;
  56
  57         va_start(args, format);
  58         if (vprintf_stderr_func == NULL) {
  59                 char buffer[1024];
  60                 retval = _mach_vsnprintf(buffer, sizeof(buffer), format, args);
  61                 write(__STDERR_FILENO, buffer, retval);
  62         } else {
  63                 retval = (*vprintf_stderr_func)(format, args);
  64         }
  65         va_end(args);
  66
  67         return retval;
  68 }