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
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
|
/*
* Portable xxxat() functions.
*
* No copyright is claimed. This code is in the public domain; do with
* it what you wish.
*
* Written by Karel Zak <kzak@redhat.com>
*/
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <sys/stat.h>
#include "at.h"
#include "c.h"
#ifdef HAVE_FSTATAT
int fstat_at(int dir, const char *dirname __attribute__ ((__unused__)),
const char *filename, struct stat *st, int nofollow)
{
return fstatat(dir, filename, st,
nofollow ? AT_SYMLINK_NOFOLLOW : 0);
}
#else
int fstat_at(int dir, const char *dirname, const char *filename,
struct stat *st, int nofollow)
{
if (*filename != '/') {
char path[PATH_MAX];
int len;
len = snprintf(path, sizeof(path), "%s/%s", dirname, filename);
if (len < 0 || len + 1 > sizeof(path))
return -1;
return nofollow ? lstat(path, st) : stat(path, st);
}
return nofollow ? lstat(filename, st) : stat(filename, st);
}
#endif
#ifdef HAVE_FSTATAT
int open_at(int dir, const char *dirname __attribute__ ((__unused__)),
const char *filename, int flags)
{
return openat(dir, filename, flags);
}
#else
int open_at(int dir, const char *dirname, const char *filename, int flags)
{
if (*filename != '/') {
char path[PATH_MAX];
int len;
len = snprintf(path, sizeof(path), "%s/%s", dirname, filename);
if (len < 0 || len + 1 > sizeof(path))
return -1;
return open(path, flags);
}
return open(filename, flags);
}
#endif
FILE *fopen_at(int dir, const char *dirname, const char *filename, int flags,
const char *mode)
{
int fd = open_at(dir, dirname, filename, flags);
if (fd < 0)
return NULL;
return fdopen(fd, mode);
}
#ifdef HAVE_FSTATAT
ssize_t readlink_at(int dir, const char *dirname __attribute__ ((__unused__)),
const char *pathname, char *buf, size_t bufsiz)
{
return readlinkat(dir, pathname, buf, bufsiz);
}
#else
ssize_t readlink_at(int dir, const char *dirname, const char *pathname,
char *buf, size_t bufsiz)
{
if (*pathname != '/') {
char path[PATH_MAX];
int len;
len = snprintf(path, sizeof(path), "%s/%s", dirname, pathname);
if (len < 0 || len + 1 > sizeof(path))
return -1;
return readlink(path, buf, bufsiz);
}
return readlink(pathname, buf, bufsiz);
}
#endif
#ifdef TEST_PROGRAM_AT
#include <errno.h>
#include <sys/types.h>
#include <dirent.h>
#include <string.h>
int main(int argc, char *argv[])
{
DIR *dir;
struct dirent *d;
char *dirname;
if (argc != 2) {
fprintf(stderr, "usage: %s <directory>\n", argv[0]);
exit(EXIT_FAILURE);
}
dirname = argv[1];
dir = opendir(dirname);
if (!dir)
err(EXIT_FAILURE, "cannot open %s", dirname);
while ((d = readdir(dir))) {
struct stat st;
FILE *f;
printf("%32s ", d->d_name);
if (fstat_at(dirfd(dir), dirname, d->d_name, &st, 0) == 0)
printf("%16jd bytes ", st.st_size);
else
printf("%16s bytes ", "???");
f = fopen_at(dirfd(dir), dirname, d->d_name, O_RDONLY, "r");
printf(" %s\n", f ? "OK" : strerror(errno));
if (f)
fclose(f);
}
closedir(dir);
return EXIT_SUCCESS;
}
#endif
|
