Mercurial > archived > louis > perso > liblxcstats

comparison utils.c @ 0:6ce4443e7545

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Add the draft of an API to collect statistics on LXC
author Louis Opter <kalessin@kalessin.fr>
date Wed, 29 Dec 2010 23:28:14 +0100
parents
children 50215911acb3
comparison
equal deleted inserted replaced
-1:000000000000 0:6ce4443e7545
1 #include <sys/types.h>
2 #include <sys/mman.h>
3 #include <sys/stat.h>
4
5 #include <assert.h>
6 #include <err.h>
7 #include <errno.h>
8 #include <fcntl.h>
9 #include <dirent.h>
10 #include <stdlib.h>
11 #include <string.h>
12 #include <unistd.h>
13
14 #include "_lxcstats.h"
15
16 char *
17 _lxcst_join_path(char *dest, size_t size, const char *left, const char *right)
18 {
19 if (*right != '/') {
20 _lxcst_strlcpy(dest, left, size);
21 _lxcst_strlcat(dest, "/", size);
22 _lxcst_strlcat(dest, right, size);
23 } else {
24 _lxcst_strlcpy(dest, right, size);
25 }
26
27 return (dest);
28 }
29
30 int
31 _lxcst_isdir(const struct _lxcst_controller *hdl, const struct dirent *d)
32 {
33 struct stat sb;
34 char buf[PATH_MAX];
35
36 _lxcst_join_path(buf, sizeof(buf), hdl->cgroup_dir, d->d_name);
37
38 if (stat(buf, &sb) == -1) {
39 warn("can't stat file: %s", buf);
40 return (0);
41 }
42
43 return (sb.st_mode & S_IFDIR);
44 }
45
46 /*
47 * Files under cgroups are virtual and always have a size of zero so we have to
48 * do some reallocs.
49 */
50 ssize_t
51 _lxcst_read_file(const char *path, char **content)
52 {
53 char buf[1024];
54 int fd;
55 ssize_t ret;
56 ssize_t size;
57 char *p;
58 int sverrno;
59
60 assert(path);
61 assert(content);
62
63 *content = NULL;
64 size = 0;
65
66 fd = open(path, O_RDONLY);
67 if (fd != -1) {
68
69 while (1) {
70 ret = read(fd, buf, sizeof(buf));
71 if (ret == -1) {
72 if (errno == EINTR)
73 continue ;
74 break ;
75 }
76 if (ret == 0)
77 break ;
78
79 p = realloc(*content, size + ret);
80 if (!p)
81 break ;
82
83 *content = p;
84 memcpy(&content[0][size], buf, ret);
85 size += ret;
86 }
87
88 if (*content) {
89 close(fd);
90 return (size);
91 }
92
93 sverrno = errno;
94 close(fd);
95 errno = sverrno;
96 }
97
98 free(*content);
99 return (ret);
100 }