diff options
Diffstat (limited to 'src/tail.c')
| -rw-r--r-- | src/tail.c | 30 |
1 files changed, 22 insertions, 8 deletions
diff --git a/src/tail.c b/src/tail.c index bc1d04a8f..c9736ca5b 100644 --- a/src/tail.c +++ b/src/tail.c @@ -1025,7 +1025,7 @@ recheck (struct File_spec *f, bool blocking) if (f->fd == -1) { error (0, 0, - _("%s has appeared; following end of new file"), + _("%s has appeared; following new file"), quote (pretty_name (f))); } else @@ -1036,7 +1036,7 @@ recheck (struct File_spec *f, bool blocking) /* 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"), + _("%s has been replaced; following new file"), quote (pretty_name (f))); } } @@ -1055,6 +1055,12 @@ recheck (struct File_spec *f, bool blocking) } } + /* FIXME: When a log is rotated, daemons tend to log to the + old file descriptor until the new file is present and + the daemon is sent a signal. Therefore tail may miss entries + being written to the old file. Perhaps we should keep + the older file open and continue to monitor it until + data is written to a new file. */ if (new_file) { /* Start at the beginning of the file. */ @@ -1193,13 +1199,16 @@ tail_forever (struct File_spec *f, size_t n_files, double sleep_interval) /* reset counter */ f[i].n_unchanged_stats = 0; + /* XXX: This is only a heuristic, as the file may have also + been truncated and written to if st_size >= size + (in which case we ignore new data <= size). */ if (S_ISREG (mode) && stats.st_size < f[i].size) { error (0, 0, _("%s: file truncated"), name); - last = i; - xlseek (fd, stats.st_size, SEEK_SET, name); - f[i].size = stats.st_size; - continue; + /* Assume the file was truncated to 0, + and therefore output all "new" data. */ + xlseek (fd, 0, SEEK_SET, name); + f[i].size = 0; } if (i != last) @@ -1330,12 +1339,17 @@ check_fspec (struct File_spec *fspec, int wd, int *prev_wd) return; } + /* XXX: This is only a heuristic, as the file may have also + been truncated and written to if st_size >= size + (in which case we ignore new data <= size). + Though in the inotify case it's more likely we'll get + separate events for truncate() and write(). */ if (S_ISREG (fspec->mode) && stats.st_size < fspec->size) { error (0, 0, _("%s: file truncated"), name); *prev_wd = wd; - xlseek (fspec->fd, stats.st_size, SEEK_SET, name); - fspec->size = stats.st_size; + xlseek (fspec->fd, 0, SEEK_SET, name); + fspec->size = 0; } else if (S_ISREG (fspec->mode) && stats.st_size == fspec->size && timespec_cmp (fspec->mtime, get_stat_mtime (&stats)) == 0) |