1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
|
#define _XOPEN_SOURCE 700
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdnoreturn.h>
#include <string.h>
#include <dirent.h>
#include <sys/stat.h>
#include <unistd.h>
static char path[PATH_MAX] = "/sys/devices";
static size_t pathlen;
static int ret;
static void
error(const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
vfprintf(stderr, fmt, ap);
va_end(ap);
if (fmt[0] && fmt[strlen(fmt) - 1] == ':') {
fputc(' ', stderr);
perror(NULL);
} else {
fputc('\n', stderr);
}
ret = 1;
}
static void
trigger(int fd, const char *name)
{
static const char action[] = "add";
fd = openat(fd, name, O_WRONLY);
if (fd == -1) {
error("open %s:", path);
} else {
if (write(fd, action, sizeof(action) - 1) != (ssize_t)(sizeof(action) - 1))
error("write %s:", path);
close(fd);
}
}
static void
search(int fd, const char *name)
{
DIR *dir;
struct dirent *d;
char *nul;
size_t oldlen;
struct stat st;
fd = openat(fd, name, O_RDONLY | O_DIRECTORY);
if (fd == -1) {
error("opendir %s:", path);
return;
}
dir = fdopendir(fd);
if (!dir) {
error("opendir %s:", path);
return;
}
oldlen = pathlen;
for (;; pathlen = oldlen) {
errno = 0;
d = readdir(dir);
if (!d)
break;
if (strcmp(d->d_name, ".") == 0 || strcmp(d->d_name, "..") == 0)
continue;
path[pathlen++] = '/';
nul = memccpy(path + pathlen, d->d_name, '\0', sizeof(path) - pathlen);
if (!nul) {
error("path too large");
continue;
}
pathlen = nul - path - 1;
if (fstatat(fd, d->d_name, &st, AT_SYMLINK_NOFOLLOW) == -1) {
error("stat %s:", path);
continue;
}
if (S_ISDIR(st.st_mode))
search(fd, d->d_name);
else if (S_ISREG(st.st_mode) && strcmp(d->d_name, "uevent") == 0)
trigger(fd, d->d_name);
}
path[pathlen] = '\0';
if (errno)
error("readdir %s", path);
closedir(dir);
}
int
main(int argc, char *argv[])
{
pathlen = strlen(path);
search(AT_FDCWD, path);
return ret;
}
|
