chiark / gitweb /
Fix mis-merged trackdb_open().
[disorder] / lib / logfd.c
CommitLineData
460b9539 1/*
2 * This file is part of DisOrder
38b8221f 3 * Copyright (C) 2005, 2007 Richard Kettlewell
460b9539 4 *
e7eb3a27 5 * This program is free software: you can redistribute it and/or modify
460b9539 6 * it under the terms of the GNU General Public License as published by
e7eb3a27 7 * the Free Software Foundation, either version 3 of the License, or
460b9539 8 * (at your option) any later version.
e7eb3a27
RK
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
460b9539 15 * You should have received a copy of the GNU General Public License
e7eb3a27 16 * along with this program. If not, see <http://www.gnu.org/licenses/>.
460b9539 17 */
132a5a4a
RK
18/** @file lib/logfd.c
19 * @brief Redirect subprocess stderr to DisOrder server's log
20 */
460b9539 21
05b75f8d 22#include "common.h"
460b9539 23
24#include <unistd.h>
460b9539 25#include <errno.h>
26
27#include "syscalls.h"
28#include "logfd.h"
29#include "event.h"
30#include "log.h"
31
460b9539 32/* called when bytes are available and at eof */
33static int logfd_readable(ev_source attribute((unused)) *ev,
34 ev_reader *reader,
460b9539 35 void *ptr,
36 size_t bytes,
37 int eof,
38 void *u) {
39 char *nl;
40 const char *tag = u;
41 int len;
42
43 while((nl = memchr(ptr, '\n', bytes))) {
44 len = nl - (char *)ptr;
45 ev_reader_consume(reader, len + 1);
46 info("%s: %.*s", tag, len, (char *)ptr);
47 ptr = nl + 1;
48 bytes -= len + 1;
49 }
50 if(eof && bytes) {
51 info("%s: %.*s", tag, (int)bytes, (char *)ptr);
52 ev_reader_consume(reader, bytes);
53 }
460b9539 54 return 0;
55}
56
57/* called when a read error occurs */
58static int logfd_error(ev_source attribute((unused)) *ev,
460b9539 59 int errno_value,
60 void *u) {
61 const char *tag = u;
62
63 error(errno_value, "error reading log pipe from %s", tag);
460b9539 64 return 0;
65}
66
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RK
67/** @brief Create file descriptor for a subprocess to log to
68 * @param ev Event loop
69 * @param tag Tag for this log
70 * @return File descriptor
71 *
72 * Returns a file descriptor which a subprocess can log to. The normal thing
73 * to do would be to dup2() this fd onto the subprocess's stderr (and to close
74 * it in the parent).
75 *
76 * Any lines written to this fd (i.e. by the subprocess) will be logged via
77 * info(), with @p tag included.
78 */
460b9539 79int logfd(ev_source *ev, const char *tag) {
80 int p[2];
81
82 xpipe(p);
83 cloexec(p[0]);
84 nonblock(p[0]);
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RK
85 if(!ev_reader_new(ev, p[0], logfd_readable, logfd_error, (void *)tag,
86 "logfd"))
460b9539 87 fatal(errno, "error calling ev_reader_new");
88 return p[1];
89}
90
91/*
92Local Variables:
93c-basic-offset:2
94comment-column:40
95fill-column:79
96indent-tabs-mode:nil
97End:
98*/