server/log-stderr.c

   1 /* nbdkit
   2  * Copyright (C) 2013-2018 Red Hat Inc.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions are
   6  * met:
   7  *
   8  * * Redistributions of source code must retain the above copyright
   9  * notice, this list of conditions and the following disclaimer.
  10  *
  11  * * Redistributions in binary form must reproduce the above copyright
  12  * notice, this list of conditions and the following disclaimer in the
  13  * documentation and/or other materials provided with the distribution.
  14  *
  15  * * Neither the name of Red Hat nor the names of its contributors may be
  16  * used to endorse or promote products derived from this software without
  17  * specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  21  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
  22  * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR
  23  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  24  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  25  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
  26  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  27  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  28  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  29  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32
  33 #include <config.h>
  34
  35 #include <stdio.h>
  36 #include <stdlib.h>
  37 #include <stdarg.h>
  38 #include <string.h>
  39 #include <unistd.h>
  40 #include <errno.h>
  41
  42 #include "internal.h"
  43
  44 /* Note: preserves the previous value of errno. */
  45 void
  46 log_stderr_verror (const char *fs, va_list args)
  47 {
  48   int err = errno;              /* must be first line of function */
  49
  50   const char *name = threadlocal_get_name ();
  51   size_t instance_num = threadlocal_get_instance_num ();
  52   int tty;
  53
  54   flockfile (stderr);
  55   tty = isatty (fileno (stderr));
  56   if (tty) fputs ("\033[1;31m", stderr);
  57
  58   fprintf (stderr, "%s: ", program_name);
  59
  60   if (name) {
  61     fprintf (stderr, "%s", name);
  62     if (instance_num > 0)
  63       fprintf (stderr, "[%zu]", instance_num);
  64     fprintf (stderr, ": ");
  65   }
  66
  67   fprintf (stderr, "error: ");
  68   errno = err;                  /* must restore in case fs contains %m */
  69   vfprintf (stderr, fs, args);
  70   fprintf (stderr, "\n");
  71
  72   if (tty) fputs ("\033[0m", stderr);
  73
  74   funlockfile (stderr);
  75
  76   errno = err;                  /* must be last line of function */
  77 }