} \
while (0)
+#define CLOSE_FD(Fd, Name) \
+ do \
+ { \
+ if ((Fd) != -1 && (Fd) != STDIN_FILENO && close (Fd)) \
+ { \
+ error (0, errno, "closing %s (fd=%d)", (Name), (Fd)); \
+ } \
+ } \
+ while (0)
+
+
/* Number of items to tail. */
#define DEFAULT_N_LINES 10
enum Follow_mode
{
- /* FIXME */
+ /* FIXME: describe */
follow_name,
- /* FIXME */
+ /* FIXME: describe */
follow_descriptor,
};
dev_t dev;
ino_t ino;
+ /* FIXME: describe */
unsigned int no_change_counter;
+
+ /* FIXME: describe */
+ int missing;
};
+/* FIXME: describe */
+static int allow_missing;
+
/* If nonzero, interpret the numeric argument as the number of lines.
Otherwise, interpret it as the number of bytes. */
static int count_lines;
/* FIXME: make follow_name the default? */
static enum Follow_mode follow_mode;
-/* If nonzero, read from the end of one file until killed. */
+/* If nonzero, read from the ends of all specified files until killed. */
static int forever;
-/* If nonzero, read from the end of multiple files until killed. */
-static int forever_multiple;
-
/* If nonzero, count from start of file instead of end. */
static int from_start;
static struct option const long_options[] =
{
+ {"allow-missing", required_argument, NULL, 11},
{"bytes", required_argument, NULL, 'c'},
{"follow", no_argument, NULL, 'f'},
{"follow-descriptor", no_argument, NULL, 12},
/* Make `pos' a multiple of `BUFSIZ' (0 if the file is short), so that all
reads will be on block boundaries, which might increase efficiency. */
pos -= bytes_read;
+ /* FIXME: check lseek return value */
lseek (fd, pos, SEEK_SET);
bytes_read = safe_read (fd, buffer, bytes_read);
if (bytes_read == -1)
if (pos == 0)
{
/* Not enough lines in the file; print the entire file. */
+ /* FIXME: check lseek return value */
lseek (fd, (off_t) 0, SEEK_SET);
return 0;
}
pos -= BUFSIZ;
+ /* FIXME: check lseek return value */
lseek (fd, pos, SEEK_SET);
}
while ((bytes_read = safe_read (fd, buffer, BUFSIZ)) > 0);
}
/* Display file FILENAME from the current position in FD to the end.
- If `forever' is nonzero, keep reading from the end of the file
- until killed. Return the number of bytes read from the file. */
+ Return the number of bytes read from the file. */
static long
dump_remainder (const char *pretty_filename, int fd)
long total;
total = 0;
-output:
while ((bytes_read = safe_read (fd, buffer, BUFSIZ)) > 0)
{
XWRITE (STDOUT_FILENO, buffer, bytes_read);
}
if (bytes_read == -1)
error (EXIT_FAILURE, errno, "%s", pretty_filename);
+
if (forever)
+ fflush (stdout);
+
+ return total;
+}
+
+/* FIXME: describe */
+
+static void
+recheck (struct File_spec *f)
+{
+ /* open/fstat the file and announce if dev/ino
+ have changed */
+ struct stat new_stats;
+ int fd;
+ int fail = 0;
+ int is_stdin = (STREQ (f->name, "-"));
+
+ fd = (is_stdin ? STDIN_FILENO : open (f->name, O_RDONLY));
+
+ /* If the open fails because the file doesn't exist,
+ then mark the file as missing. */
+ f->missing = (allow_missing && fd == -1 && errno == ENOENT);
+
+ if (fd == -1 || fstat (fd, &new_stats) < 0)
{
- fflush (stdout);
- sleep (sleep_interval);
- goto output;
+ fail = 1;
+ error (0, errno, "%s", f->pretty_name);
}
- else
+ else if (!S_ISREG (new_stats.st_mode)
+ && !S_ISFIFO (new_stats.st_mode))
{
- if (forever_multiple)
- fflush (stdout);
+ fail = 1;
+ error (0, 0,
+ _("%s has been replaced with a non-regular file; \
+cannot follow end of non-regular file"),
+ f->pretty_name);
}
- return total;
+ if (fail)
+ {
+ CLOSE_FD (fd, f->pretty_name);
+ CLOSE_FD (f->fd, f->pretty_name);
+ f->fd = -1;
+ }
+ else if (f->ino != new_stats.st_ino || f->dev != new_stats.st_dev)
+ {
+ /* Close the old one. */
+ CLOSE_FD (f->fd, f->pretty_name);
+
+ /* File has been replaced (e.g., via log rotation) --
+ tail the new one. */
+ error (0, 0,
+ _("%s has been replaced; following end of new file"),
+ f->pretty_name);
+
+ f->fd = fd;
+ f->size = new_stats.st_size;
+ f->dev = new_stats.st_dev;
+ f->ino = new_stats.st_ino;
+ f->no_change_counter = 0;
+ /* FIXME: check lseek return value */
+ lseek (f->fd, new_stats.st_size, SEEK_SET);
+ }
+ else if (f->missing)
+ {
+ error (0, 0, _("%s has reappeared"), f->pretty_name);
+ f->missing = 0;
+
+ f->fd = fd;
+ f->size = new_stats.st_size;
+ f->dev = new_stats.st_dev;
+ f->ino = new_stats.st_ino;
+ f->no_change_counter = 0;
+ /* FIXME: check lseek return value */
+ lseek (f->fd, new_stats.st_size, SEEK_SET);
+ }
+ else
+ {
+ CLOSE_FD (fd, f->pretty_name);
+ }
}
-/* Tail NFILES (>1) files forever until killed.
+/* Tail NFILES files forever, or until killed.
The pertinent information for each file is stored in an entry of F.
- Loop over each of them, doing an fstat to see if they have changed size.
+ Loop over each of them, doing an fstat to see if they have changed size,
+ and an occasional open/fstat to see if any dev/ino pair has changed.
If none of them have changed size in one iteration, sleep for a
while and try again. Continue until the user interrupts us. */
while (1)
{
int i;
- int changed;
+ int any_changed;
+ int any_live_files;
- changed = 0;
+ any_live_files = 0;
+ any_changed = 0;
for (i = 0; i < nfiles; i++)
{
struct stat stats;
- if (f[i].fd < 0)
+ if (f[i].fd < 0 && !f[i].missing)
continue;
+
+ any_live_files = 1;
+
if (fstat (f[i].fd, &stats) < 0)
{
error (0, errno, "%s", f[i].pretty_name);
if (++f[i].no_change_counter > max_no_change_count
&& follow_mode == follow_name)
{
- /* open/fstat the file and announce if dev/ino
- have changed */
- struct stat new_stats;
- int fd;
- int fail = 0;
- int is_stdin = (STREQ (f[i].name, "-"));
-
- fd = (is_stdin ? STDIN_FILENO : open (f[i].name, O_RDONLY));
-
- if (fd == -1 || fstat (fd, &new_stats) < 0)
- {
- fail = 1;
- error (0, errno, "%s", f[i].pretty_name);
- }
- else if (!S_ISREG (new_stats.st_mode))
- {
- fail = 1;
- error (0, 0,
- _("%s has been replaced with a non-regular file; \
-cannot follow end of non-regular file"),
- f[i].pretty_name);
- }
-
- if (fail)
- {
- if (fd != STDIN_FILENO)
- close (fd);
- if (f[i].fd != STDIN_FILENO)
- close (f[i].fd);
- f[i].fd = -1;
- }
- else if (f[i].ino != new_stats.st_ino
- || f[i].dev != new_stats.st_dev)
- {
- /* Close the old one. */
- if (f[i].fd != STDIN_FILENO)
- close (f[i].fd);
-
- /* File has been replaced (e.g., via log rotation) --
- tail the new one. */
- error (0, 0,
- _("%s has been replaced; following end of new file"),
- f[i].pretty_name);
- f[i].fd = fd;
- f[i].size = new_stats.st_size;
- f[i].dev = new_stats.st_dev;
- f[i].ino = new_stats.st_ino;
- f[i].no_change_counter = 0;
- lseek (f[i].fd, new_stats.st_size, SEEK_SET);
- }
- else
- {
- close (fd);
- }
-
+ recheck (&f[i]);
f[i].no_change_counter = 0;
- };
+ }
+
continue;
}
+ /* FIXME-now:
+ Otherwise, a file that's unlinked or moved aside, yet always
+ growing will never be recognized has having been renamed. */
+
/* This file has changed size. Print out what we can, and
then keep looping. */
- changed = 1;
+ any_changed = 1;
/* reset counter */
f[i].no_change_counter = 0;
{
write_header (f[i].pretty_name, _("file truncated"));
last = i;
+ /* FIXME: check lseek return value */
lseek (f[i].fd, stats.st_size, SEEK_SET);
f[i].size = stats.st_size;
continue;
f[i].size += dump_remainder (f[i].pretty_name, f[i].fd);
}
+ if (!any_live_files /* FIXME-now: && ! allow_missing */ )
+ {
+ error (0, 0, _("no files remaining"));
+ break;
+ }
+
/* If none of the files changed size, sleep. */
- if (! changed)
+ if (!any_changed)
sleep (sleep_interval);
}
}
if (from_start)
{
if (S_ISREG (stats.st_mode))
- lseek (fd, n_bytes, SEEK_CUR);
+ {
+ /* FIXME: check lseek return value */
+ lseek (fd, n_bytes, SEEK_CUR);
+ }
else if (start_bytes (pretty_filename, fd, n_bytes))
- return 1;
+ {
+ return 1;
+ }
dump_remainder (pretty_filename, fd);
}
else
more bytes than have been requested. So reposition the
file pointer to the incoming current position and print
everything after that. */
+ /* FIXME: check lseek return value */
lseek (fd, current_pos, SEEK_SET);
}
else
{
/* There are more bytes remaining than were requested.
Back up. */
+ /* FIXME: check lseek return value */
lseek (fd, -n_bytes, SEEK_END);
}
dump_remainder (pretty_filename, fd);
fd = open (f->name, O_RDONLY);
}
+ f->missing = (allow_missing && fd == -1 && errno == ENOENT);
+
if (fd == -1)
{
- if (forever_multiple)
+ if (forever)
f->fd = -1;
error (0, errno, "%s", f->pretty_name);
errors = 1;
if (print_headers)
write_header (f->pretty_name, NULL);
errors = tail (f->pretty_name, fd, n_units);
- if (forever_multiple)
+ if (forever)
{
/* FIXME: duplicate code */
if (fstat (fd, &stats) < 0)
error (0, errno, "%s", f->pretty_name);
errors = 1;
}
- else if (!S_ISREG (stats.st_mode))
+ else if (!S_ISREG (stats.st_mode) && !S_ISFIFO (stats.st_mode))
{
error (0, 0, _("%s: cannot follow end of non-regular file"),
f->pretty_name);
}
if (errors)
{
- if (!is_stdin)
- close (fd);
+ CLOSE_FD (fd, f->pretty_name);
f->fd = -1;
}
else
int c;
count_lines = 1;
- forever = forever_multiple = from_start = print_headers = 0;
+ forever = from_start = print_headers = 0;
while ((c = getopt_long (argc, argv, "c:n:fqs:v", long_options, NULL)) != -1)
{
forever = 1;
break;
+ case 11:
+ allow_missing = 1;
+ break;
+
case 12:
follow_mode = follow_descriptor;
break;
n_files = argc - optind;
file = argv + optind;
- if (n_files > 1 && forever)
- {
- forever_multiple = 1;
- forever = 0;
- }
-
if (n_files == 0)
{
static char *dummy_stdin = "-";
for (i = 0; i < n_files; i++)
exit_status |= tail_file (&F[i], n_units);
- if (forever_multiple)
+ if (forever)
tail_forever (F, n_files);
if (have_read_stdin && close (0) < 0)
projects / thirdparty / coreutils.git / commitdiff
