On 6/24/21 8:50 AM, Paul Eggert wrote:
inotify_init can return 1025 even if called first thing, so we also need
to dup2 the result of early inotify_init down to 3 (or whatever), or at
least to check that it's less than 1024. Choosing 3 is a tricky
business, since it's not clear what fds the C library actually needs.
When looking into this I decided it was cleaner to fix coreutils by
using 'poll' instead of 'select', as Kamil suggested. I installed the
attached patches to do that. The last patch fixes the bug.
Thanks for reporting the problem.
From 145707949f9479f00dce41f479549f7629d7d0c9 Mon Sep 17 00:00:00 2001
From: Paul Eggert <egg...@cs.ucla.edu>
Date: Sat, 26 Jun 2021 18:23:52 -0700
Subject: [PATCH 1/3] =?UTF-8?q?maint:=20while=20(1)=20=E2=86=92=20while=20?=
=?UTF-8?q?(true)?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
---
src/basenc.c | 2 +-
src/chcon.c | 2 +-
src/chmod.c | 2 +-
src/chown-core.c | 2 +-
src/csplit.c | 2 +-
src/cut.c | 2 +-
src/date.c | 2 +-
src/dd.c | 2 +-
src/dircolors.c | 2 +-
src/du.c | 2 +-
src/expr.c | 12 ++++++------
src/head.c | 4 ++--
src/join.c | 2 +-
src/ls.c | 4 ++--
src/nproc.c | 2 +-
src/od.c | 6 +++---
src/ptx.c | 2 +-
src/pwd.c | 6 +++---
src/realpath.c | 2 +-
src/remove.c | 2 +-
src/rmdir.c | 2 +-
src/runcon.c | 2 +-
src/sort.c | 2 +-
src/sum.c | 2 +-
src/system.h | 2 +-
src/tac-pipe.c | 6 +++---
src/tac.c | 2 +-
src/tail.c | 12 ++++++------
src/tsort.c | 2 +-
29 files changed, 47 insertions(+), 47 deletions(-)
diff --git a/src/basenc.c b/src/basenc.c
index 7e22363bf..5c97a3652 100644
--- a/src/basenc.c
+++ b/src/basenc.c
@@ -605,7 +605,7 @@ z85_encode (char const *restrict in, size_t inlen,
unsigned int val;
size_t outidx = 0;
- while (1)
+ while (true)
{
if (inlen == 0)
{
diff --git a/src/chcon.c b/src/chcon.c
index dc2258de0..88010848e 100644
--- a/src/chcon.c
+++ b/src/chcon.c
@@ -315,7 +315,7 @@ process_files (char **files, int bit_flags)
FTS *fts = xfts_open (files, bit_flags, NULL);
- while (1)
+ while (true)
{
FTSENT *ent;
diff --git a/src/chmod.c b/src/chmod.c
index 78d9c9cba..160a0c537 100644
--- a/src/chmod.c
+++ b/src/chmod.c
@@ -335,7 +335,7 @@ process_files (char **files, int bit_flags)
FTS *fts = xfts_open (files, bit_flags, NULL);
- while (1)
+ while (true)
{
FTSENT *ent;
diff --git a/src/chown-core.c b/src/chown-core.c
index a0b2f670f..4d816de4a 100644
--- a/src/chown-core.c
+++ b/src/chown-core.c
@@ -524,7 +524,7 @@ chown_files (char **files, int bit_flags,
FTS *fts = xfts_open (files, bit_flags | stat_flags, NULL);
- while (1)
+ while (true)
{
FTSENT *ent;
diff --git a/src/csplit.c b/src/csplit.c
index f188e8894..e1fb66ed2 100644
--- a/src/csplit.c
+++ b/src/csplit.c
@@ -496,7 +496,7 @@ load_buffer (void)
if (bytes_wanted < hold_count)
bytes_wanted = hold_count;
- while (1)
+ while (true)
{
b = get_new_buffer (bytes_wanted);
bytes_avail = b->bytes_alloc; /* Size of buffer returned. */
diff --git a/src/cut.c b/src/cut.c
index 78b82c80e..f4d44c211 100644
--- a/src/cut.c
+++ b/src/cut.c
@@ -306,7 +306,7 @@ cut_fields (FILE *stream)
That is because a non-delimited line has exactly one field. */
buffer_first_field = (suppress_non_delimited ^ !print_kth (1));
- while (1)
+ while (true)
{
if (field_idx == 1 && buffer_first_field)
{
diff --git a/src/date.c b/src/date.c
index d5eebaf25..4a7a4e243 100644
--- a/src/date.c
+++ b/src/date.c
@@ -313,7 +313,7 @@ batch_convert (char const *input_filename, char const *format,
line = NULL;
buflen = 0;
ok = true;
- while (1)
+ while (true)
{
ssize_t line_length = getline (&line, &buflen, in_stream);
if (line_length < 0)
diff --git a/src/dd.c b/src/dd.c
index d284357a4..fc5108f8b 100644
--- a/src/dd.c
+++ b/src/dd.c
@@ -2179,7 +2179,7 @@ dd_copy (void)
alloc_ibuf ();
alloc_obuf ();
- while (1)
+ while (true)
{
if (status_level == STATUS_PROGRESS)
{
diff --git a/src/dircolors.c b/src/dircolors.c
index fea0cdf01..b765ded9f 100644
--- a/src/dircolors.c
+++ b/src/dircolors.c
@@ -253,7 +253,7 @@ dc_parse_stream (FILE *fp, char const *filename)
if (term == NULL || *term == '\0')
term = "none";
- while (1)
+ while (true)
{
char *keywd, *arg;
bool unrecognized;
diff --git a/src/du.c b/src/du.c
index d4760a36c..efd519706 100644
--- a/src/du.c
+++ b/src/du.c
@@ -684,7 +684,7 @@ du_files (char **files, int bit_flags)
{
FTS *fts = xfts_open (files, bit_flags, NULL);
- while (1)
+ while (true)
{
FTSENT *ent;
diff --git a/src/expr.c b/src/expr.c
index ec76f7607..41185a8f8 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -781,7 +781,7 @@ eval5 (bool evaluate)
trace ("eval5");
#endif
l = eval6 (evaluate);
- while (1)
+ while (true)
{
if (nextarg (":"))
{
@@ -812,7 +812,7 @@ eval4 (bool evaluate)
trace ("eval4");
#endif
l = eval5 (evaluate);
- while (1)
+ while (true)
{
if (nextarg ("*"))
fxn = multiply;
@@ -851,7 +851,7 @@ eval3 (bool evaluate)
trace ("eval3");
#endif
l = eval4 (evaluate);
- while (1)
+ while (true)
{
if (nextarg ("+"))
fxn = plus;
@@ -881,7 +881,7 @@ eval2 (bool evaluate)
trace ("eval2");
#endif
l = eval3 (evaluate);
- while (1)
+ while (true)
{
VALUE *r;
enum
@@ -960,7 +960,7 @@ eval1 (bool evaluate)
trace ("eval1");
#endif
l = eval2 (evaluate);
- while (1)
+ while (true)
{
if (nextarg ("&"))
{
@@ -991,7 +991,7 @@ eval (bool evaluate)
trace ("eval");
#endif
l = eval1 (evaluate);
- while (1)
+ while (true)
{
if (nextarg ("|"))
{
diff --git a/src/head.c b/src/head.c
index 844c5636a..7b2a44041 100644
--- a/src/head.c
+++ b/src/head.c
@@ -520,7 +520,7 @@ elide_tail_lines_pipe (char const *filename, int fd, uintmax_t n_elide,
/* Always read into a fresh buffer.
Read, (producing no output) until we've accumulated at least
n_elide newlines, or until EOF, whichever comes first. */
- while (1)
+ while (true)
{
n_read = safe_read (fd, tmp->buffer, BUFSIZ);
if (n_read == 0 || n_read == SAFE_READ_ERROR)
@@ -676,7 +676,7 @@ elide_tail_lines_seekable (char const *pretty_filename, int fd,
if (n_lines && bytes_read && buffer[bytes_read - 1] != line_end)
--n_lines;
- while (1)
+ while (true)
{
/* Scan backward, counting the newlines in this bufferfull. */
diff --git a/src/join.c b/src/join.c
index 57f4665bc..f22ffda53 100644
--- a/src/join.c
+++ b/src/join.c
@@ -598,7 +598,7 @@ prjoin (struct line const *line1, struct line const *line2)
const struct outlist *o;
o = outlist;
- while (1)
+ while (true)
{
if (o->file == 0)
{
diff --git a/src/ls.c b/src/ls.c
index 4586b5ecc..1b20f17fe 100644
--- a/src/ls.c
+++ b/src/ls.c
@@ -2980,7 +2980,7 @@ print_dir (char const *name, char const *realname, bool command_line_arg)
/* Read the directory entries, and insert the subfiles into the 'cwd_file'
table. */
- while (1)
+ while (true)
{
/* Set errno to zero so we can distinguish between a readdir failure
and when readdir simply finds that there are no more entries. */
@@ -5112,7 +5112,7 @@ print_many_per_line (void)
size_t pos = 0;
/* Print the next row. */
- while (1)
+ while (true)
{
struct fileinfo const *f = sorted_file[filesno];
size_t name_length = length_of_file_name_and_frills (f);
diff --git a/src/nproc.c b/src/nproc.c
index e06b7a431..55a51bfbe 100644
--- a/src/nproc.c
+++ b/src/nproc.c
@@ -86,7 +86,7 @@ main (int argc, char **argv)
enum nproc_query mode = NPROC_CURRENT_OVERRIDABLE;
- while (1)
+ while (true)
{
int c = getopt_long (argc, argv, "", longopts, NULL);
if (c == -1)
diff --git a/src/od.c b/src/od.c
index 5b2d507a1..f04e0ccb7 100644
--- a/src/od.c
+++ b/src/od.c
@@ -1387,7 +1387,7 @@ dump (void)
if (limit_bytes_to_format)
{
- while (1)
+ while (true)
{
size_t n_needed;
if (current_offset >= end_offset)
@@ -1409,7 +1409,7 @@ dump (void)
}
else
{
- while (1)
+ while (true)
{
ok &= read_block (bytes_per_block, block[idx], &n_bytes_read);
if (n_bytes_read < bytes_per_block)
@@ -1462,7 +1462,7 @@ dump_strings (void)
uintmax_t address = n_bytes_to_skip;
bool ok = true;
- while (1)
+ while (true)
{
size_t i;
int c;
diff --git a/src/ptx.c b/src/ptx.c
index fc4d0912f..c488b1192 100644
--- a/src/ptx.c
+++ b/src/ptx.c
@@ -837,7 +837,7 @@ find_occurs_in_text (int file_index)
/* Read and process a single input line or sentence, one word at a
time. */
- while (1)
+ while (true)
{
if (word_regex.string)
diff --git a/src/pwd.c b/src/pwd.c
index 3a18c3d81..5dfda31bd 100644
--- a/src/pwd.c
+++ b/src/pwd.c
@@ -178,7 +178,7 @@ find_dir_entry (struct stat *dot_sb, struct file_name *file_name,
use_lstat = (parent_sb.st_dev != dot_sb->st_dev);
found = false;
- while (1)
+ while (true)
{
struct dirent const *dp;
struct stat ent_sb;
@@ -279,7 +279,7 @@ robust_getcwd (struct file_name *file_name)
if (stat (".", &dot_sb) < 0)
die (EXIT_FAILURE, errno, _("failed to stat %s"), quoteaf ("."));
- while (1)
+ while (true)
{
/* If we've reached the root, we're done. */
if (SAME_INODE (dot_sb, *root_dev_ino))
@@ -340,7 +340,7 @@ main (int argc, char **argv)
atexit (close_stdout);
- while (1)
+ while (true)
{
int c = getopt_long (argc, argv, "LP", longopts, NULL);
if (c == -1)
diff --git a/src/realpath.c b/src/realpath.c
index 4c9ffbcb4..8e4aabfdf 100644
--- a/src/realpath.c
+++ b/src/realpath.c
@@ -185,7 +185,7 @@ main (int argc, char **argv)
atexit (close_stdout);
- while (1)
+ while (true)
{
int c = getopt_long (argc, argv, "eLmPqsz", longopts, NULL);
if (c == -1)
diff --git a/src/remove.c b/src/remove.c
index da380e0a7..5dd0479e6 100644
--- a/src/remove.c
+++ b/src/remove.c
@@ -590,7 +590,7 @@ rm (char *const *file, struct rm_options const *x)
FTS *fts = xfts_open (file, bit_flags, NULL);
- while (1)
+ while (true)
{
FTSENT *ent;
diff --git a/src/rmdir.c b/src/rmdir.c
index 3a9911ff0..149d4659a 100644
--- a/src/rmdir.c
+++ b/src/rmdir.c
@@ -117,7 +117,7 @@ remove_parents (char *dir)
bool ok = true;
strip_trailing_slashes (dir);
- while (1)
+ while (true)
{
slash = strrchr (dir, '/');
if (slash == NULL)
diff --git a/src/runcon.c b/src/runcon.c
index fda8bb398..716170092 100644
--- a/src/runcon.c
+++ b/src/runcon.c
@@ -124,7 +124,7 @@ main (int argc, char **argv)
atexit (close_stdout);
- while (1)
+ while (true)
{
int option_index = 0;
int c = getopt_long (argc, argv, "+r:t:u:l:c", long_options,
diff --git a/src/sort.c b/src/sort.c
index d98796b96..451bfe08a 100644
--- a/src/sort.c
+++ b/src/sort.c
@@ -3552,7 +3552,7 @@ static void
merge_loop (struct merge_node_queue *queue,
size_t total_lines, FILE *tfp, char const *temp_output)
{
- while (1)
+ while (true)
{
struct merge_node *node = queue_pop (queue);
diff --git a/src/sum.c b/src/sum.c
index 218db808d..f9641dbb1 100644
--- a/src/sum.c
+++ b/src/sum.c
@@ -179,7 +179,7 @@ sysv_sum_file (char const *file, int print_name)
}
}
- while (1)
+ while (true)
{
size_t bytes_read = safe_read (fd, buf, sizeof buf);
diff --git a/src/system.h b/src/system.h
index 676f5f562..ce264b121 100644
--- a/src/system.h
+++ b/src/system.h
@@ -277,7 +277,7 @@ dot_or_dotdot (char const *file_name)
static inline struct dirent const *
readdir_ignoring_dot_and_dotdot (DIR *dirp)
{
- while (1)
+ while (true)
{
struct dirent const *dp = readdir (dirp);
if (dp == NULL || ! dot_or_dotdot (dp->d_name))
diff --git a/src/tac-pipe.c b/src/tac-pipe.c
index 5fefd631b..5192607d9 100644
--- a/src/tac-pipe.c
+++ b/src/tac-pipe.c
@@ -58,7 +58,7 @@ buf_init_from_stdin (Buf *x, char eol_byte)
#define OBS (&(x->obs))
obstack_init (OBS);
- while (1)
+ while (true)
{
char *buf = (char *) malloc (BUFFER_SIZE);
size_t bytes_read;
@@ -185,7 +185,7 @@ find_bol (const Buf *x,
tmp = line_ptr_decrement (x, last_bol);
last_bol_ptr = tmp.ptr;
i = tmp.i;
- while (1)
+ while (true)
{
char *nl = memrchr (x->p[i].start, last_bol_ptr, eol_byte);
if (nl)
@@ -250,7 +250,7 @@ tac_mem ()
bol.i = x.n_bufs - 1;
bol.ptr = ONE_PAST_END (&x, bol.i);
- while (1)
+ while (true)
{
Line_ptr new_bol;
if (! find_bol (&x, &bol, &new_bol, eol_byte))
diff --git a/src/tac.c b/src/tac.c
index 1a01c005e..cbc3deac9 100644
--- a/src/tac.c
+++ b/src/tac.c
@@ -505,7 +505,7 @@ copy_to_temp (FILE **g_tmp, char **g_tempfile, int input_fd, char const *file)
if (!temp_stream (&fp, &file_name))
return -1;
- while (1)
+ while (true)
{
size_t bytes_read = safe_read (input_fd, G_buffer, read_size);
if (bytes_read == 0)
diff --git a/src/tail.c b/src/tail.c
index b91fcfd82..7c3ae22d9 100644
--- a/src/tail.c
+++ b/src/tail.c
@@ -453,7 +453,7 @@ dump_remainder (bool want_header, char const *pretty_filename, int fd,
uintmax_t n_remaining = n_bytes;
n_written = 0;
- while (1)
+ while (true)
{
char buffer[BUFSIZ];
size_t n = MIN (n_remaining, BUFSIZ);
@@ -641,7 +641,7 @@ pipe_lines (char const *pretty_filename, int fd, uintmax_t n_lines,
tmp = xmalloc (sizeof (LBUFFER));
/* Input is always read into a fresh buffer. */
- while (1)
+ while (true)
{
n_read = safe_read (fd, tmp->buffer, BUFSIZ);
if (n_read == 0 || n_read == SAFE_READ_ERROR)
@@ -780,7 +780,7 @@ pipe_bytes (char const *pretty_filename, int fd, uintmax_t n_bytes,
tmp = xmalloc (sizeof (CBUFFER));
/* Input is always read into a fresh buffer. */
- while (1)
+ while (true)
{
n_read = safe_read (fd, tmp->buffer, BUFSIZ);
if (n_read == 0 || n_read == SAFE_READ_ERROR)
@@ -900,7 +900,7 @@ start_lines (char const *pretty_filename, int fd, uintmax_t n_lines,
if (n_lines == 0)
return 0;
- while (1)
+ while (true)
{
char buffer[BUFSIZ];
size_t bytes_read = safe_read (fd, buffer, BUFSIZ);
@@ -1160,7 +1160,7 @@ tail_forever (struct File_spec *f, size_t n_files, double sleep_interval)
last = n_files - 1;
- while (1)
+ while (true)
{
size_t i;
bool any_input = false;
@@ -1617,7 +1617,7 @@ tail_forever_inotify (int wd, struct File_spec *f, size_t n_files,
ensure that watched files can be re-added when following by name.
This loop blocks on the 'safe_read' call until a new event is notified.
But when --pid=P is specified, tail usually waits via the select. */
- while (1)
+ while (true)
{
struct File_spec *fspec;
struct inotify_event *ev;
diff --git a/src/tsort.c b/src/tsort.c
index 92bd1b2af..33b3419c0 100644
--- a/src/tsort.c
+++ b/src/tsort.c
@@ -452,7 +452,7 @@ tsort (char const *file)
init_tokenbuffer (&tokenbuffer);
- while (1)
+ while (true)
{
/* T2. Next Relation. */
size_t len = readtoken (stdin, DELIM, sizeof (DELIM) - 1, &tokenbuffer);
--
2.30.2
From bce0fe7fa095edfe52d0724d9287a9043346316b Mon Sep 17 00:00:00 2001
From: Paul Eggert <egg...@cs.ucla.edu>
Date: Sat, 26 Jun 2021 18:23:52 -0700
Subject: [PATCH 2/3] tail: fix abuse2 test race
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
* tests/tail-2/inotify-hash-abuse2.sh (fastpoll):
Fix race where tailed file ‘f’ temporarily did not exist.
---
tests/tail-2/inotify-hash-abuse2.sh | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/tests/tail-2/inotify-hash-abuse2.sh b/tests/tail-2/inotify-hash-abuse2.sh
index 2c40236af..4b36b7a33 100755
--- a/tests/tail-2/inotify-hash-abuse2.sh
+++ b/tests/tail-2/inotify-hash-abuse2.sh
@@ -33,8 +33,8 @@ for mode in '' '---disable-inotify'; do
for i in $(seq 200); do
kill -0 $pid || break;
- mv f g
- touch f
+ touch g
+ mv g f
done
# Ensure tail hasn't aborted
--
2.30.2
From 3f83f82d2612d0c6ea8f1983350e85ef3cc0fc7a Mon Sep 17 00:00:00 2001
From: Paul Eggert <egg...@cs.ucla.edu>
Date: Sat, 26 Jun 2021 18:23:52 -0700
Subject: [PATCH 3/3] tail: use poll, not select
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
This fixes an unlikely stack out-of-bounds write reported by
Stepan Broz via Kamil Dudka (Bug#49209).
* bootstrap.conf (gnulib_modules): Replace select with poll.
* src/tail.c: Do not include <sys/select.h>.
[!_AIX]: Include poll.h.
(check_output_alive) [!_AIX]: Use poll instead of select.
(tail_forever_inotify): Likewise. Simplify logic, as there is no
need for a ‘while (len <= evbuf_off)’ loop.
---
NEWS | 4 ++
bootstrap.conf | 2 +-
src/tail.c | 100 +++++++++++++++++++------------------------------
3 files changed, 44 insertions(+), 62 deletions(-)
diff --git a/NEWS b/NEWS
index 02b57470f..97532d3d0 100644
--- a/NEWS
+++ b/NEWS
@@ -43,6 +43,10 @@ GNU coreutils NEWS -*- outline -*-
Previously a chunk starting after 128KiB, output the wrong part of the file.
[bug introduced in coreutils-8.26]
+ tail -f no longer overruns a stack buffer when given too many files
+ to follow and ulimit -n exceeds 1024.
+ [bug introduced in coreutils-7.5]
+
tr no longer crashes when using --complement with certain
invalid combinations of case character classes.
[bug introduced in coreutils-8.6]
diff --git a/bootstrap.conf b/bootstrap.conf
index daea2824c..e7ed7e5ff 100644
--- a/bootstrap.conf
+++ b/bootstrap.conf
@@ -193,6 +193,7 @@ gnulib_modules="
physmem
pipe-posix
pipe2
+ poll
posix-shell
posixtm
posixver
@@ -227,7 +228,6 @@ gnulib_modules="
save-cwd
savedir
savewd
- select
selinux-at
setenv
settime
diff --git a/src/tail.c b/src/tail.c
index 7c3ae22d9..99977afa7 100644
--- a/src/tail.c
+++ b/src/tail.c
@@ -28,12 +28,9 @@
#include <stdio.h>
#include <assert.h>
#include <getopt.h>
-#include <sys/select.h>
+#include <poll.h>
#include <sys/types.h>
#include <signal.h>
-#ifdef _AIX
-# include <poll.h>
-#endif
#include "system.h"
#include "argmatch.h"
@@ -351,27 +348,12 @@ check_output_alive (void)
if (! monitor_output)
return;
-#ifdef _AIX
- /* select on AIX was seen to give a readable event immediately. */
struct pollfd pfd;
pfd.fd = STDOUT_FILENO;
pfd.events = POLLERR;
if (poll (&pfd, 1, 0) >= 0 && (pfd.revents & POLLERR))
die_pipe ();
-#else
- struct timeval delay;
- delay.tv_sec = delay.tv_usec = 0;
-
- fd_set rfd;
- FD_ZERO (&rfd);
- FD_SET (STDOUT_FILENO, &rfd);
-
- /* readable event on STDOUT is equivalent to POLLERR,
- and implies an error condition on output like broken pipe. */
- if (select (STDOUT_FILENO + 1, &rfd, NULL, NULL, &delay) == 1)
- die_pipe ();
-#endif
}
static bool
@@ -1616,7 +1598,7 @@ tail_forever_inotify (int wd, struct File_spec *f, size_t n_files,
/* Wait for inotify events and handle them. Events on directories
ensure that watched files can be re-added when following by name.
This loop blocks on the 'safe_read' call until a new event is notified.
- But when --pid=P is specified, tail usually waits via the select. */
+ But when --pid=P is specified, tail usually waits via poll. */
while (true)
{
struct File_spec *fspec;
@@ -1636,54 +1618,51 @@ tail_forever_inotify (int wd, struct File_spec *f, size_t n_files,
return false;
}
- /* When watching a PID, ensure that a read from WD will not block
- indefinitely. */
- while (len <= evbuf_off)
+ if (len <= evbuf_off)
{
- struct timeval delay; /* how long to wait for file changes. */
+ /* Poll for inotify events. When watching a PID, ensure
+ that a read from WD will not block indefinitely.
+ If MONITOR_OUTPUT, also poll for a broken output pipe. */
- if (pid)
+ int file_change;
+ struct pollfd pfd[2];
+ do
{
- if (writer_is_dead)
- exit (EXIT_SUCCESS);
+ /* How many ms to wait for changes. -1 means wait forever. */
+ int delay = -1;
- writer_is_dead = (kill (pid, 0) != 0 && errno != EPERM);
-
- if (writer_is_dead)
- delay.tv_sec = delay.tv_usec = 0;
- else
+ if (pid)
{
- delay.tv_sec = (time_t) sleep_interval;
- delay.tv_usec = 1000000 * (sleep_interval - delay.tv_sec);
+ if (writer_is_dead)
+ exit (EXIT_SUCCESS);
+
+ writer_is_dead = (kill (pid, 0) != 0 && errno != EPERM);
+
+ if (writer_is_dead || sleep_interval <= 0)
+ delay = 0;
+ else if (sleep_interval < INT_MAX / 1000 - 1)
+ {
+ /* delay = ceil (sleep_interval * 1000), sans libm. */
+ double ddelay = sleep_interval * 1000;
+ delay = ddelay;
+ delay += delay < ddelay;
+ }
}
+
+ pfd[0].fd = wd;
+ pfd[0].events = POLLIN;
+ pfd[1].fd = STDOUT_FILENO;
+ pfd[1].events = pfd[1].revents = 0;
+ file_change = poll (pfd, monitor_output + 1, delay);
}
+ while (file_change == 0);
- fd_set rfd;
- FD_ZERO (&rfd);
- FD_SET (wd, &rfd);
- if (monitor_output)
- FD_SET (STDOUT_FILENO, &rfd);
-
- int file_change = select (MAX (wd, STDOUT_FILENO) + 1,
- &rfd, NULL, NULL, pid ? &delay: NULL);
-
- if (file_change == 0)
- continue;
- else if (file_change == -1)
- die (EXIT_FAILURE, errno,
- _("error waiting for inotify and output events"));
- else if (FD_ISSET (STDOUT_FILENO, &rfd))
- {
- /* readable event on STDOUT is equivalent to POLLERR,
- and implies an error on output like broken pipe. */
- die_pipe ();
- }
- else
- break;
- }
+ if (file_change < 0)
+ die (EXIT_FAILURE, errno,
+ _("error waiting for inotify and output events"));
+ if (pfd[1].revents)
+ die_pipe ();
- if (len <= evbuf_off)
- {
len = safe_read (wd, evbuf, evlen);
evbuf_off = 0;
@@ -2444,8 +2423,7 @@ main (int argc, char **argv)
if (forever && ignore_fifo_and_pipe (F, n_files))
{
/* If stdout is a fifo or pipe, then monitor it
- so that we exit if the reader goes away.
- Note select() on a regular file is always readable. */
+ so that we exit if the reader goes away. */
struct stat out_stat;
if (fstat (STDOUT_FILENO, &out_stat) < 0)
die (EXIT_FAILURE, errno, _("standard output"));
--
2.30.2
