diff options
Diffstat (limited to 'src/tail.c')
| -rw-r--r-- | src/tail.c | 57 |
1 files changed, 48 insertions, 9 deletions
diff --git a/src/tail.c b/src/tail.c index f87d2f249..4171d18f6 100644 --- a/src/tail.c +++ b/src/tail.c @@ -132,11 +132,24 @@ enum header_mode multiple_files, always, never }; -/* FIXME: describe -- add option */ -static unsigned long max_n_unchanged_stats_between_opens = 5; - -/* FIXME: describe -- add option */ -static unsigned long max_n_consecutive_size_changes = 200; +/* When tailing a file by name, if there have been this many consecutive + stat calls for which the size has remained the same, then open/fstat + the file to determine if that file name is still associated with the + same device/inode-number pair as before. This option is meaningful only + when following by name. --max-unchanged-stats=N */ +#define DEFAULT_MAX_N_UNCHANGED_STATS_BETWEEN_OPENS 5 +static unsigned long max_n_unchanged_stats_between_opens = + DEFAULT_MAX_N_UNCHANGED_STATS_BETWEEN_OPENS; + +/* This variable is used to ensure that a file that is unlinked or moved + aside, yet always growing will be recognized as having been renamed. + After detecting this many consecutive size changes for a file, open/fstat + the file to determine if that file name is still associated with the + same device/inode-number pair as before. This option is meaningful only + when following by name. --max-n-consecutive-size-changes=N */ +#define DEFAULT_MAX_N_CONSECUTIVE_SIZE_CHANGES 200 +static unsigned long max_n_consecutive_size_changes = + DEFAULT_MAX_N_CONSECUTIVE_SIZE_CHANGES; /* The name this program was run with. */ char *program_name; @@ -159,6 +172,8 @@ static struct option const long_options[] = {"bytes", required_argument, NULL, 'c'}, {"follow", optional_argument, NULL, 'f'}, {"lines", required_argument, NULL, 'n'}, + {"max-unchanged-stats", required_argument, NULL, CHAR_MAX + 2}, + {"max-consecutive-size-changes", required_argument, NULL, CHAR_MAX + 3}, {"quiet", no_argument, NULL, 'q'}, {"silent", no_argument, NULL, 'q'}, {"sleep-interval", required_argument, NULL, 's'}, @@ -189,6 +204,8 @@ With no FILE, or when FILE is -, read standard input.\n\ -c, --bytes=N output the last N bytes\n\ -f, --follow[={name|descriptor}] output appended data as the file grows\n\ -n, --lines=N output the last N lines, instead of last 10\n\ + --max-unchanged-stats=N FIXME describe and mention default\n\ + --max-consecutive-size-changes=N FIXME describe and mention default\n\ -q, --quiet, --silent never output headers giving file names\n\ -s, --sleep-interval=S with -f, sleep S seconds between iterations\n\ -v, --verbose always output headers giving file names\n\ @@ -782,7 +799,7 @@ tail_forever (struct File_spec *f, int nfiles) ++f[i].n_consecutive_size_changes; /* Ensure that a file that's unlinked or moved aside, yet always - growing will be recognized has having been renamed. */ + growing will be recognized as having been renamed. */ if (follow_mode == Follow_name && (f[i].n_consecutive_size_changes > max_n_consecutive_size_changes)) @@ -1142,7 +1159,7 @@ parse_obsolescent_option (int argc, const char *const *argv, strtol_error s_err; unsigned long int tmp_ulong; char *end; - s_err = xstrtoul (n_string, &end, 0, &tmp_ulong, NULL); + s_err = xstrtoul (n_string, &end, 10, &tmp_ulong, NULL); if (s_err == LONGINT_OK && tmp_ulong <= OFF_T_MAX) *n_units = (off_t) tmp_ulong; else @@ -1227,7 +1244,7 @@ parse_options (int argc, char **argv, { strtol_error s_err; unsigned long int tmp_ulong; - s_err = xstrtoul (optarg, NULL, 0, &tmp_ulong, "bkm"); + s_err = xstrtoul (optarg, NULL, 10, &tmp_ulong, "bkm"); if (s_err == LONGINT_INVALID) { error (EXIT_FAILURE, 0, "%s: %s", optarg, @@ -1259,6 +1276,28 @@ parse_options (int argc, char **argv, allow_missing = 1; break; + case CHAR_MAX + 2: + /* --max-unchanged-stats=N */ + if (xstrtoul (optarg, NULL, 10, + &max_n_unchanged_stats_between_opens, "") != LONGINT_OK) + { + error (EXIT_FAILURE, 0, + _("%s: invalid maximum number of unchanged stats between opens"), + optarg); + } + break; + + case CHAR_MAX + 3: + /* --max-consecutive-size-changes=N */ + if (xstrtoul (optarg, NULL, 10, &max_n_consecutive_size_changes, "") + != LONGINT_OK) + { + error (EXIT_FAILURE, 0, + _("%s: invalid maximum number of consecutive size changes"), + optarg); + } + break; + case 'q': *header_mode = never; break; @@ -1267,7 +1306,7 @@ parse_options (int argc, char **argv, { strtol_error s_err; unsigned long int tmp_ulong; - s_err = xstrtoul (optarg, NULL, 0, &tmp_ulong, ""); + s_err = xstrtoul (optarg, NULL, 10, &tmp_ulong, ""); if (s_err != LONGINT_OK || tmp_ulong > UINT_MAX) { error (EXIT_FAILURE, 0, |