util.c

制作2.6内核的CLFS时 patch包

  putc ('\n', stderr);
  fflush (stderr);
  fatal_exit (0);
}

void
memory_fatal (void)
{
  fatal ("out of memory");
}

void
read_fatal (void)
{
  pfatal ("read error");
}

void
write_fatal (void)
{
  pfatal ("write error");
}

/* Say something from patch, something from the system, then silence . . . */

void
pfatal (char const *format, ...)
{
  int errnum = errno;
  va_list args;
  fprintf (stderr, "%s: **** ", program_name);
  va_start (args, format);
  vfprintf (stderr, format, args);
  va_end (args);
  fflush (stderr); /* perror bypasses stdio on some hosts.  */
  errno = errnum;
  perror (" ");
  fflush (stderr);
  fatal_exit (0);
}

/* Tell the user something.  */

void
say (char const *format, ...)
{
  va_list args;
  va_start (args, format);
  vfprintf (stdout, format, args);
  va_end (args);
  fflush (stdout);
}

/* Get a response from the user, somehow or other. */

void
ask (char const *format, ...)
{
  static int ttyfd = -2;
  int r;
  va_list args;

  va_start (args, format);
  vfprintf (stdout, format, args);
  va_end (args);
  fflush (stdout);

  if (ttyfd == -2)
    {
      /* If standard output is not a tty, don't bother opening /dev/tty,
	 since it's unlikely that stdout will be seen by the tty user.
	 The isatty test also works around a bug in GNU Emacs 19.34 under Linux
	 which makes a call-process `patch' hang when it reads from /dev/tty.
	 POSIX.1-2001 XCU line 26599 requires that we read /dev/tty,
	 though.  */
      ttyfd = (posixly_correct || isatty (STDOUT_FILENO)
	       ? open (TTY_DEVICE, O_RDONLY)
	       : -1);
    }

  if (ttyfd < 0)
    {
      /* No terminal at all -- default it.  */
      printf ("\n");
      buf[0] = '\n';
      buf[1] = '\0';
    }
  else
    {
      size_t s = 0;
      while ((r = read (ttyfd, buf + s, bufsize - 1 - s)) == bufsize - 1 - s
	     && buf[bufsize - 2] != '\n')
	{
	  s = bufsize - 1;
	  bufsize *= 2;
	  buf = realloc (buf, bufsize);
	  if (!buf)
	    memory_fatal ();
	}
      if (r == 0)
	printf ("EOF\n");
      else if (r < 0)
	{
	  perror ("tty read");
	  fflush (stderr);
	  close (ttyfd);
	  ttyfd = -1;
	  r = 0;
	}
      buf[s + r] = '\0';
    }
}

/* Return nonzero if it OK to reverse a patch.  */

bool
ok_to_reverse (char const *format, ...)
{
  bool r = false;

  if (noreverse || ! (force && verbosity == SILENT))
    {
      va_list args;
      va_start (args, format);
      vfprintf (stdout, format, args);
      va_end (args);
    }

  if (noreverse)
    {
      printf ("  Skipping patch.\n");
      skip_rest_of_patch = true;
    }
  else if (force)
    {
      if (verbosity != SILENT)
	printf ("  Applying it anyway.\n");
    }
  else if (batch)
    {
      say (reverse ? "  Ignoring -R.\n" : "  Assuming -R.\n");
      r = true;
    }
  else
    {
      ask (reverse ? "  Ignore -R? [n] " : "  Assume -R? [n] ");
      r = *buf == 'y';
      if (! r)
	{
	  ask ("Apply anyway? [n] ");
	  if (*buf != 'y')
	    {
	      if (verbosity != SILENT)
		say ("Skipping patch.\n");
	      skip_rest_of_patch = true;
	    }
	}
    }

  return r;
}

/* How to handle certain events when not in a critical region. */

#define NUM_SIGS (sizeof (sigs) / sizeof (*sigs))
static int const sigs[] = {
#ifdef SIGHUP
       SIGHUP,
#endif
#ifdef SIGPIPE
       SIGPIPE,
#endif
#ifdef SIGTERM
       SIGTERM,
#endif
#ifdef SIGXCPU
       SIGXCPU,
#endif
#ifdef SIGXFSZ
       SIGXFSZ,
#endif
       SIGINT
};

#if !HAVE_SIGPROCMASK
#define sigset_t int
#define sigemptyset(s) (*(s) = 0)
#ifndef sigmask
#define sigmask(sig) (1 << ((sig) - 1))
#endif
#define sigaddset(s, sig) (*(s) |= sigmask (sig))
#define sigismember(s, sig) ((*(s) & sigmask (sig)) != 0)
#ifndef SIG_BLOCK
#define SIG_BLOCK 0
#endif
#ifndef SIG_UNBLOCK
#define SIG_UNBLOCK (SIG_BLOCK + 1)
#endif
#ifndef SIG_SETMASK
#define SIG_SETMASK (SIG_BLOCK + 2)
#endif
#define sigprocmask(how, n, o) \
  ((how) == SIG_BLOCK \
   ? ((o) ? *(o) = sigblock (*(n)) : sigblock (*(n))) \
   : (how) == SIG_UNBLOCK \
   ? sigsetmask (((o) ? *(o) = sigblock (0) : sigblock (0)) & ~*(n)) \
   : (o ? *(o) = sigsetmask (*(n)) : sigsetmask (*(n))))
#if !HAVE_SIGSETMASK
#define sigblock(mask) 0
#define sigsetmask(mask) 0
#endif
#endif

static sigset_t initial_signal_mask;
static sigset_t signals_to_block;

#if ! HAVE_SIGACTION
static RETSIGTYPE fatal_exit_handler (int) __attribute__ ((noreturn));
static RETSIGTYPE
fatal_exit_handler (int sig)
{
  signal (sig, SIG_IGN);
  fatal_exit (sig);
}
#endif

void
set_signals (bool reset)
{
  int i;
#if HAVE_SIGACTION
  struct sigaction initial_act, fatal_act;
  fatal_act.sa_handler = fatal_exit;
  sigemptyset (&fatal_act.sa_mask);
  fatal_act.sa_flags = 0;
#define setup_handler(sig) sigaction (sig, &fatal_act, (struct sigaction *) 0)
#else
#define setup_handler(sig) signal (sig, fatal_exit_handler)
#endif

  if (!reset)
    {
#ifdef SIGCHLD
      /* System V fork+wait does not work if SIGCHLD is ignored.  */
      signal (SIGCHLD, SIG_DFL);
#endif
      sigemptyset (&signals_to_block);
      for (i = 0;  i < NUM_SIGS;  i++)
	{
	  bool ignoring_signal;
#if HAVE_SIGACTION
	  if (sigaction (sigs[i], (struct sigaction *) 0, &initial_act) != 0)
	    continue;
	  ignoring_signal = initial_act.sa_handler == SIG_IGN;
#else
	  ignoring_signal = signal (sigs[i], SIG_IGN) == SIG_IGN;
#endif
	  if (! ignoring_signal)
	    {
	      sigaddset (&signals_to_block, sigs[i]);
	      setup_handler (sigs[i]);
	    }
	}
    }
  else
    {
      /* Undo the effect of ignore_signals.  */
#if HAVE_SIGPROCMASK || HAVE_SIGSETMASK
      sigprocmask (SIG_SETMASK, &initial_signal_mask, (sigset_t *) 0);
#else
      for (i = 0;  i < NUM_SIGS;  i++)
	if (sigismember (&signals_to_block, sigs[i]))
	  setup_handler (sigs[i]);
#endif
    }
}

/* How to handle certain events when in a critical region. */

void
ignore_signals (void)
{
#if HAVE_SIGPROCMASK || HAVE_SIGSETMASK
  sigprocmask (SIG_BLOCK, &signals_to_block, &initial_signal_mask);
#else
  int i;
  for (i = 0;  i < NUM_SIGS;  i++)
    if (sigismember (&signals_to_block, sigs[i]))
      signal (sigs[i], SIG_IGN);
#endif
}

void
exit_with_signal (int sig)
{
  sigset_t s;
  signal (sig, SIG_DFL);
  sigemptyset (&s);
  sigaddset (&s, sig);
  sigprocmask (SIG_UNBLOCK, &s, (sigset_t *) 0);
  raise (sig);
  exit (2);
}

int
systemic (char const *command)
{
  if (debug & 8)
    say ("+ %s\n", command);
  fflush (stdout);
  return system (command);
}

/* Replace '/' with '\0' in FILENAME if it marks a place that
   needs testing for the existence of directory.  Return the address
   of the last location replaced, or 0 if none were replaced.  */
static char *
replace_slashes (char *filename)
{
  char *f;
  char *last_location_replaced = 0;
  char const *component_start;

  for (f = filename + FILESYSTEM_PREFIX_LEN (filename);  ISSLASH (*f);  f++)
    continue;

  component_start = f;

  for (; *f; f++)
    if (ISSLASH (*f))
      {
	char *slash = f;

	/* Treat multiple slashes as if they were one slash.  */
	while (ISSLASH (f[1]))
	  f++;

	/* Ignore slashes at the end of the path.  */
	if (! f[1])
	  break;

	/* "." and ".." need not be tested.  */
	if (! (slash - component_start <= 2
	       && component_start[0] == '.' && slash[-1] == '.'))
	  {
	    *slash = '\0';
	    last_location_replaced = slash;
	  }

	component_start = f + 1;
      }

  return last_location_replaced;
}

/* Make sure we'll have the directories to create a file.
   Ignore the last element of `filename'.  */

static void
makedirs (register char *filename)
{
  register char *f;
  register char *flim = replace_slashes (filename);

  if (flim)
    {
      /* Create any missing directories, replacing NULs by '/'s.
	 Ignore errors.  We may have to keep going even after an EEXIST,
	 since the path may contain ".."s; and when there is an EEXIST
	 failure the system may return some other error number.
	 Any problems will eventually be reported when we create the file.  */
      for (f = filename;  f <= flim;  f++)
	if (!*f)
	  {
	    mkdir (filename,
		   S_IRUSR|S_IWUSR|S_IXUSR
		   |S_IRGRP|S_IWGRP|S_IXGRP
		   |S_IROTH|S_IWOTH|S_IXOTH);
	    *f = '/';
	  }
    }
}

/* Remove empty ancestor directories of FILENAME.
   Ignore errors, since the path may contain ".."s, and when there
   is an EEXIST failure the system may return some other error number.  */
void
removedirs (char *filename)
{
  size_t i;

  for (i = strlen (filename);  i != 0;  i--)
    if (ISSLASH (filename[i])
	&& ! (ISSLASH (filename[i - 1])
	      || (filename[i - 1] == '.'
		  && (i == 1
		      || ISSLASH (filename[i - 2])
		      || (filename[i - 2] == '.'
			  && (i == 2
			      || ISSLASH (filename[i - 3])))))))
      {
	filename[i] = '\0';
	if (rmdir (filename) == 0 && verbosity == VERBOSE)
	  say ("Removed empty directory %s\n", quotearg (filename));
	filename[i] = '/';
      }
}

static time_t initial_time;

void
init_time (void)
{
  time (&initial_time);
}

/* Make filenames more reasonable. */

char *
fetchname (char *at, int strip_leading, time_t *pstamp)
{
    char *name;
    register char *t;
    int sleading = strip_leading;
    time_t stamp = (time_t) -1;

    while (ISSPACE ((unsigned char) *at))
	at++;
    if (debug & 128)
	say ("fetchname %s %d\n", at, strip_leading);

    name = at;
    /* Strip up to `strip_leading' leading slashes and null terminate.
       If `strip_leading' is negative, strip all leading slashes.  */
    for (t = at;  *t;  t++)
      {
	if (ISSLASH (*t))
	  {
	    while (ISSLASH (t[1]))
	      t++;
	    if (strip_leading < 0 || --sleading >= 0)
		name = t+1;
	  }
	else if (ISSPACE ((unsigned char) *t))
	  {
	    /* Allow file names with internal spaces,
	       but only if a tab separates the file name from the date.  */
	    char const *u = t;
	    while (*u != '\t' && ISSPACE ((unsigned char) u[1]))
	      u++;
	    if (*u != '\t' && strchr (u + 1, '\t'))
	      continue;

	    if (set_time | set_utc)
	      stamp = str2time (&u, initial_time,
				set_utc ? 0L : TM_LOCAL_ZONE);
	    else
	      {
		/* The head says the file is nonexistent if the timestamp
		   is the epoch; but the listed time is local time, not UTC,
		   and POSIX.1 allows local time offset anywhere in the range
		   -25:00 < offset < +26:00.  Match any time in that
		   range by assuming local time is -25:00 and then matching
		   any ``local'' time T in the range 0 < T < 25+26 hours.  */
		stamp = str2time (&u, initial_time, -25L * 60 * 60);
		if (0 < stamp && stamp < (25 + 26) * 60L * 60)
		  stamp = 0;
	      }

	    if (*u && ! ISSPACE ((unsigned char) *u))
	      stamp = (time_t) -1;

	    *t = '\0';
	    break;
	  }
      }

    if (!*name)
      return 0;

    /* If the name is "/dev/null", ignore the name and mark the file
       as being nonexistent.  The name "/dev/null" appears in patches
       regardless of how NULL_DEVICE is spelled.  */
    if (strcmp (at, "/dev/null") == 0)
      {
	if (pstamp)
	  *pstamp = 0;
	return 0;
      }

    /* Ignore the name if it doesn't have enough slashes to strip off.  */
    if (0 < sleading)
      return 0;

    if (pstamp)
      *pstamp = stamp;

    return savestr (name);
}

void
Fseek (FILE *stream, file_offset offset, int ptrname)
{
  if (file_seek (stream, offset, ptrname) != 0)
    pfatal ("fseek");
}