1 /* inotifyd.c - inotify daemon.
2 *
3 * Copyright 2013 Ashwini Kumar <ak.ashwini1981@gmail.com>
4 * Copyright 2013 Kyungwan Han <asura321@gmail.com>
5 *
6 * No Standard.
7
8 USE_INOTIFYD(NEWTOY(inotifyd, "<2", TOYFLAG_USR|TOYFLAG_BIN))
9
10 config INOTIFYD
11 bool "inotifyd"
12 default y
13 help
14 usage: inotifyd PROG FILE[:MASK] ...
15
16 When a filesystem event matching MASK occurs to a FILE, run PROG as:
17
18 PROG EVENTS FILE [DIRFILE]
19
20 If PROG is "-" events are sent to stdout.
21
22 This file is:
23 a accessed c modified e metadata change w closed (writable)
24 r opened D deleted M moved 0 closed (unwritable)
25 u unmounted o overflow x unwatchable
26
27 A file in this directory is:
28 m moved in y moved out n created d deleted
29
30 When x event happens for all FILEs, inotifyd exits (after waiting for PROG).
31 */
32
33 #define FOR_inotifyd
34 #include "toys.h"
35 #include <sys/inotify.h>
36
inotifyd_main(void)37 void inotifyd_main(void)
38 {
39 struct pollfd fds;
40 char *prog_args[5], **ss = toys.optargs;
41 char *masklist ="acew0rmyndDM uox";
42
43 fds.events = POLLIN;
44
45 *prog_args = *toys.optargs;
46 prog_args[4] = 0;
47 if ((fds.fd = inotify_init()) == -1) perror_exit(0);
48
49 // Track number of watched files. First one was program to run.
50 toys.optc--;
51
52 while (*++ss) {
53 char *path = *ss, *masks = strchr(*ss, ':');
54 int i, mask = 0;
55
56 if (!masks) mask = 0xfff; // default to all
57 else{
58 *masks++ = 0;
59 for (*masks++ = 0; *masks; masks++) {
60 i = stridx(masklist, *masks);;
61 if (i == -1) error_exit("bad mask '%c'", *masks);
62 mask |= 1<<i;
63 }
64 }
65
66 // This returns increasing numbers starting from 1, which coincidentally
67 // is the toys.optargs position of the file. (0 is program to run.)
68 if (inotify_add_watch(fds.fd, path, mask) < 0) perror_exit("%s", path);
69 }
70
71 for (;;) {
72 int ret = 0, len;
73 void *buf = 0;
74 struct inotify_event *event;
75
76 // Read next event(s)
77 ret = poll(&fds, 1, -1);
78 if (ret < 0 && errno == EINTR) continue;
79 if (ret <= 0) break;
80 xioctl(fds.fd, FIONREAD, &len);
81 event = buf = xmalloc(len);
82 len = readall(fds.fd, buf, len);
83
84 // Loop through set of events.
85 for (;;) {
86 int left = len - (((char *)event)-(char *)buf),
87 size = sizeof(struct inotify_event);
88
89 // Don't dereference event if ->len is off end of bufer
90 if (left >= size) size += event->len;
91 if (left < size) break;
92
93 if (event->mask) {
94 char *s = toybuf, *m;
95
96 for (m = masklist; *m; m++)
97 if (event->mask & (1<<(m-masklist))) *s++ = *m;
98 *s = 0;
99
100 if (**prog_args == '-' && !prog_args[0][1]) {
101 xprintf("%s\t%s\t%s\n" + 3*!event->len, toybuf,
102 toys.optargs[event->wd], event->name);
103 } else {
104 prog_args[1] = toybuf;
105 prog_args[2] = toys.optargs[event->wd];
106 prog_args[3] = event->len ? event->name : 0;
107 xrun(prog_args);
108 }
109
110 if (event->mask & IN_IGNORED) {
111 if (--toys.optc <= 0) {
112 free(buf);
113
114 goto done;
115 }
116 inotify_rm_watch(fds.fd, event->wd);
117 }
118 }
119 event = (void*)(size + (char*)event);
120 }
121 free(buf);
122 }
123
124 done:
125 toys.exitval = !!toys.signal;
126 }
127