1explain_statfs(3) Library Functions Manual explain_statfs(3)
2
6 explain_statfs - explain statfs(2) errors
7
9 #include <libexplain/statfs.h>
10 const char *explain_statfs(const char *pathname, struct statfs *data);
11 const char *explain_errno_statfs(int errnum, const char *pathname,
12 struct statfs *data);
13 void explain_message_statfs(char *message, int message_size, const char
14 *pathname, struct statfs *data);
15 void explain_message_errno_statfs(char *message, int message_size, int
16 errnum, const char *pathname, struct statfs *data);
17
19 These functions may be used to obtain explanations for errors returned
20 by the statfs(2) system call.
21 explain_statfs
23 const char *explain_statfs(const char *pathname, struct statfs *data);
24 The explain_statfs function is used to obtain an explanation of an
26 error returned by the statfs(2) system call. The least the message will
27 contain is the value of strerror(errno), but usually it will do much
28 better, and indicate the underlying cause in more detail.
29 The errno global variable will be used to obtain the error value to be
31 decoded.
32 pathname
34 The original pathname, exactly as passed to the statfs(2) sys‐
35 tem call.
36 data The original data, exactly as passed to the statfs(2) system
38 call.
39 Returns:
41 The message explaining the error. This message buffer is shared
42 by all libexplain functions which do not supply a buffer in
43 their argument list. This will be overwritten by the next call
44 to any libexplain function which shares this buffer, including
45 other threads.
46 Note: This function is not thread safe, because it shares a return buf‐
48 fer across all threads, and many other functions in this library.
49 Example: This function is intended to be used in a fashion similar to
51 the following example:
52 if (statfs(pathname, data) < 0)
53 {
54 fprintf(stderr, "%s\n", explain_statfs(pathname, data));
55 exit(EXIT_FAILURE);
56 }
57 The above code example is available pre‐packaged as the
59 explain_statfs_or_die(3) function.
60 explain_errno_statfs
62 const char *explain_errno_statfs(int errnum, const char *pathname,
63 struct statfs *data);
64 The explain_errno_statfs function is used to obtain an explanation of
66 an error returned by the statfs(2) system call. The least the message
67 will contain is the value of strerror(errno), but usually it will do
68 much better, and indicate the underlying cause in more detail.
69 errnum The error value to be decoded, usually obtained from the errno
71 global variable just before this function is called. This is
72 necessary if you need to call any code between the system call
73 to be explained and this function, because many libc functions
74 will alter the value of errno.
75 pathname
77 The original pathname, exactly as passed to the statfs(2) sys‐
78 tem call.
79 data The original data, exactly as passed to the statfs(2) system
81 call.
82 Returns:
84 The message explaining the error. This message buffer is shared
85 by all libexplain functions which do not supply a buffer in
86 their argument list. This will be overwritten by the next call
87 to any libexplain function which shares this buffer, including
88 other threads.
89 Note: This function is not thread safe, because it shares a return buf‐
91 fer across all threads, and many other functions in this library.
92 Example: This function is intended to be used in a fashion similar to
94 the following example:
95 if (statfs(pathname, data) < 0)
96 {
97 int err = errno;
98 fprintf(stderr, "%s\n", explain_errno_statfs(err, pathname,
99 data));
100 exit(EXIT_FAILURE);
101 }
102 The above code example is available pre‐packaged as the
104 explain_statfs_or_die(3) function.
105 explain_message_statfs
107 void explain_message_statfs(char *message, int message_size, const char
108 *pathname, struct statfs *data);
109 The explain_message_statfs function is used to obtain an explanation of
111 an error returned by the statfs(2) system call. The least the message
112 will contain is the value of strerror(errno), but usually it will do
113 much better, and indicate the underlying cause in more detail.
114 The errno global variable will be used to obtain the error value to be
116 decoded.
117 message The location in which to store the returned message. If a suit‐
119 able message return buffer is supplied, this function is thread
120 safe.
121 message_size
123 The size in bytes of the location in which to store the
124 returned message.
125 pathname
127 The original pathname, exactly as passed to the statfs(2) sys‐
128 tem call.
129 data The original data, exactly as passed to the statfs(2) system
131 call.
132 Example: This function is intended to be used in a fashion similar to
134 the following example:
135 if (statfs(pathname, data) < 0)
136 {
137 char message[3000];
138 explain_message_statfs(message, sizeof(message), pathname,
139 data);
140 fprintf(stderr, "%s\n", message);
141 exit(EXIT_FAILURE);
142 }
143 The above code example is available pre‐packaged as the
145 explain_statfs_or_die(3) function.
146 explain_message_errno_statfs
148 void explain_message_errno_statfs(char *message, int message_size, int
149 errnum, const char *pathname, struct statfs *data);
150 The explain_message_errno_statfs function is used to obtain an explana‐
152 tion of an error returned by the statfs(2) system call. The least the
153 message will contain is the value of strerror(errno), but usually it
154 will do much better, and indicate the underlying cause in more detail.
155 message The location in which to store the returned message. If a suit‐
157 able message return buffer is supplied, this function is thread
158 safe.
159 message_size
161 The size in bytes of the location in which to store the
162 returned message.
163 errnum The error value to be decoded, usually obtained from the errno
165 global variable just before this function is called. This is
166 necessary if you need to call any code between the system call
167 to be explained and this function, because many libc functions
168 will alter the value of errno.
169 pathname
171 The original pathname, exactly as passed to the statfs(2) sys‐
172 tem call.
173 data The original data, exactly as passed to the statfs(2) system
175 call.
176 Example: This function is intended to be used in a fashion similar to
178 the following example:
179 if (statfs(pathname, data) < 0)
180 {
181 int err = errno;
182 char message[3000];
183 explain_message_errno_statfs(message, sizeof(message), err,
184 pathname, data);
185 fprintf(stderr, "%s\n", message);
186 exit(EXIT_FAILURE);
187 }
188 The above code example is available pre‐packaged as the
190 explain_statfs_or_die(3) function.
191
193 statfs(2)
194 get file system statistics
195 explain_statfs_or_die(3)
197 get file system statistics and report errors
198
200 libexplain version 1.4
201 Copyright (C) 2009 Peter Miller
202 explain_statfs(3)