1explain_acl_get_fd(3) Library Functions Manual explain_acl_get_fd(3)
2
6 explain_acl_get_fd - explain acl_get_fd(3) errors
7
9 #include <libexplain/acl_get_fd.h>
10 const char *explain_acl_get_fd(int fildes);
11 const char *explain_errno_acl_get_fd(int errnum, int fildes);
12 void explain_message_acl_get_fd(char *message, int message_size, int
13 fildes);
14 void explain_message_errno_acl_get_fd(char *message, int message_size,
15 int errnum, int fildes);
16
18 These functions may be used to obtain explanations for errors returned
19 by the acl_get_fd(3) system call.
20 explain_acl_get_fd
22 const char *explain_acl_get_fd(int fildes);
23 The explain_acl_get_fd function is used to obtain an explanation of an
25 error returned by the acl_get_fd(3) system call. The least the message
26 will contain is the value of strerror(errno), but usually it will do
27 much better, and indicate the underlying cause in more detail.
28 The errno global variable will be used to obtain the error value to be
30 decoded.
31 fildes The original fildes, exactly as passed to the acl_get_fd(3)
33 system call.
34 Returns:
36 The message explaining the error. This message buffer is shared
37 by all libexplain functions which do not supply a buffer in
38 their argument list. This will be overwritten by the next call
39 to any libexplain function which shares this buffer, including
40 other threads.
41 Note: This function is not thread safe, because it shares a return buf‐
43 fer across all threads, and many other functions in this library.
44 Example: This function is intended to be used in a fashion similar to
46 the following example:
47 acl_t result = acl_get_fd(fildes);
48 if (result < 0)
49 {
50 fprintf(stderr, "%s\n", explain_acl_get_fd(fildes));
51 exit(EXIT_FAILURE);
52 }
53 The above code example is available pre-packaged as the
55 explain_acl_get_fd_or_die(3) function.
56 explain_errno_acl_get_fd
58 const char *explain_errno_acl_get_fd(int errnum, int fildes);
59 The explain_errno_acl_get_fd function is used to obtain an explanation
61 of an error returned by the acl_get_fd(3) system call. The least the
62 message will contain is the value of strerror(errno), but usually it
63 will do much better, and indicate the underlying cause in more detail.
64 errnum The error value to be decoded, usually obtained from the errno
66 global variable just before this function is called. This is
67 necessary if you need to call any code between the system call
68 to be explained and this function, because many libc functions
69 will alter the value of errno.
70 fildes The original fildes, exactly as passed to the acl_get_fd(3)
72 system call.
73 Returns:
75 The message explaining the error. This message buffer is shared
76 by all libexplain functions which do not supply a buffer in
77 their argument list. This will be overwritten by the next call
78 to any libexplain function which shares this buffer, including
79 other threads.
80 Note: This function is not thread safe, because it shares a return buf‐
82 fer across all threads, and many other functions in this library.
83 Example: This function is intended to be used in a fashion similar to
85 the following example:
86 acl_t result = acl_get_fd(fildes);
87 if (result < 0)
88 {
89 int err = errno;
90 fprintf(stderr, "%s\n", explain_errno_acl_get_fd(err,
91 fildes));
92 exit(EXIT_FAILURE);
93 }
94 The above code example is available pre-packaged as the
96 explain_acl_get_fd_or_die(3) function.
97 explain_message_acl_get_fd
99 void explain_message_acl_get_fd(char *message, int message_size, int
100 fildes);
101 The explain_message_acl_get_fd function is used to obtain an explana‐
103 tion of an error returned by the acl_get_fd(3) system call. The least
104 the message will contain is the value of strerror(errno), but usually
105 it will do much better, and indicate the underlying cause in more
106 detail.
107 The errno global variable will be used to obtain the error value to be
109 decoded.
110 message The location in which to store the returned message. If a suit‐
112 able message return buffer is supplied, this function is thread
113 safe.
114 message_size
116 The size in bytes of the location in which to store the
117 returned message.
118 fildes The original fildes, exactly as passed to the acl_get_fd(3)
120 system call.
121 Example: This function is intended to be used in a fashion similar to
123 the following example:
124 acl_t result = acl_get_fd(fildes);
125 if (result < 0)
126 {
127 char message[3000];
128 explain_message_acl_get_fd(message, sizeof(message),
129 fildes);
130 fprintf(stderr, "%s\n", message);
131 exit(EXIT_FAILURE);
132 }
133 The above code example is available pre-packaged as the
135 explain_acl_get_fd_or_die(3) function.
136 explain_message_errno_acl_get_fd
138 void explain_message_errno_acl_get_fd(char *message, int message_size,
139 int errnum, int fildes);
140 The explain_message_errno_acl_get_fd function is used to obtain an
142 explanation of an error returned by the acl_get_fd(3) system call. The
143 least the message will contain is the value of strerror(errno), but
144 usually it will do much better, and indicate the underlying cause in
145 more detail.
146 message The location in which to store the returned message. If a suit‐
148 able message return buffer is supplied, this function is thread
149 safe.
150 message_size
152 The size in bytes of the location in which to store the
153 returned message.
154 errnum The error value to be decoded, usually obtained from the errno
156 global variable just before this function is called. This is
157 necessary if you need to call any code between the system call
158 to be explained and this function, because many libc functions
159 will alter the value of errno.
160 fildes The original fildes, exactly as passed to the acl_get_fd(3)
162 system call.
163 Example: This function is intended to be used in a fashion similar to
165 the following example:
166 acl_t result = acl_get_fd(fildes);
167 if (result < 0)
168 {
169 int err = errno;
170 char message[3000];
171 explain_message_errno_acl_get_fd(message, sizeof(message),
172 err, fildes);
173 fprintf(stderr, "%s\n", message);
174 exit(EXIT_FAILURE);
175 }
176 The above code example is available pre-packaged as the
178 explain_acl_get_fd_or_die(3) function.
179
181 acl_get_fd(3)
182 Execute acl_get_fd(3)
183 explain_acl_get_fd_or_die(3)
185 Execute acl_get_fd(3) and report errors
186
188 libexplain version 1.4
189 Copyright (C) 2013 Peter Miller
190 explain_acl_get_fd(3)