1explain_pathconf(3) Library Functions Manual explain_pathconf(3)
2
6 explain_pathconf - explain pathconf(3) errors
7
9 #include <libexplain/pathconf.h>
10 const char *explain_pathconf(const char *pathname, int name);
11 const char *explain_errno_pathconf(int errnum, const char *pathname,
12 int name);
13 void explain_message_pathconf(char *message, int message_size, const
14 char *pathname, int name);
15 void explain_message_errno_pathconf(char *message, int message_size,
16 int errnum, const char *pathname, int name);
17
19 These functions may be used to obtain explanations for errors returned
20 by the pathconf(3) system call.
21 explain_pathconf
23 const char *explain_pathconf(const char *pathname, int name);
24 The explain_pathconf function is used to obtain an explanation of an
26 error returned by the pathconf(3) system call. The least the message
27 will contain is the value of strerror(errno), but usually it will do
28 much 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 This function is intended to be used in a fashion similar to the fol‐
34 lowing example:
35 if (pathconf(pathname, name) < 0)
36 {
37 fprintf(stderr, "%s\n", explain_pathconf(pathname, name));
38 exit(EXIT_FAILURE);
39 }
40 The above code example is available pre‐packaged as the explain_path‐
42 conf_or_die(3) function.
43 pathname
45 The original pathname, exactly as passed to the pathconf(3)
46 system call.
47 name The original name, exactly as passed to the pathconf(3) system
49 call.
50 Returns:
52 The message explaining the error. This message buffer is
53 shared by all libexplain functions which do not supply a buffer
54 in their argument list. This will be overwritten by the next
55 call to any libexplain function which shares this buffer,
56 including other threads.
57 Note: This function is not thread safe, because it shares a return buf‐
59 fer across all threads, and many other functions in this library.
60 explain_errno_pathconf
62 const char *explain_errno_pathconf(int errnum, const char *pathname,
63 int name);
64 The explain_errno_pathconf function is used to obtain an explanation of
66 an error returned by the pathconf(3) system call. The least the mes‐
67 sage will contain is the value of strerror(errnum), but usually it will
68 do much better, and indicate the underlying cause in more detail.
69 This function is intended to be used in a fashion similar to the fol‐
71 lowing example:
72 if (pathconf(pathname, name) < 0)
73 {
74 int err = errno;
75 fprintf(stderr, "%s\n", explain_errno_pathconf(err, pathname, name));
76 exit(EXIT_FAILURE);
77 }
78 The above code example is available pre‐packaged as the explain_path‐
80 conf_or_die(3) function.
81 errnum The error value to be decoded, usually obtained from the errno
83 global variable just before this function is called. This is
84 necessary if you need to call any code between the system call
85 to be explained and this function, because many libc functions
86 will alter the value of errno.
87 pathname
89 The original pathname, exactly as passed to the pathconf(3)
90 system call.
91 name The original name, exactly as passed to the pathconf(3) system
93 call.
94 Returns:
96 The message explaining the error. This message buffer is
97 shared by all libexplain functions which do not supply a buffer
98 in their argument list. This will be overwritten by the next
99 call to any libexplain function which shares this buffer,
100 including other threads.
101 Note: This function is not thread safe, because it shares a return buf‐
103 fer across all threads, and many other functions in this library.
104 explain_message_pathconf
106 void explain_message_pathconf(char *message, int message_size, const
107 char *pathname, int name);
108 The explain_message_pathconf function may be used to obtain an expla‐
110 nation of an error returned by the pathconf(3) system call. The least
111 the message will contain is the value of strerror(errno), but usually
112 it will do much better, and indicate the underlying cause in more
113 detail.
114 The errno global variable will be used to obtain the error value to be
116 decoded.
117 This function is intended to be used in a fashion similar to the fol‐
119 lowing example:
120 if (pathconf(pathname, name) < 0)
121 {
122 char message[3000];
123 explain_message_pathconf(message, sizeof(message), pathname, name);
124 fprintf(stderr, "%s\n", message);
125 exit(EXIT_FAILURE);
126 }
127 The above code example is available pre‐packaged as the explain_path‐
129 conf_or_die(3) function.
130 message The location in which to store the returned message. If a
132 suitable message return buffer is supplied, this function is
133 thread safe.
134 message_size
136 The size in bytes of the location in which to store the
137 returned message.
138 pathname
140 The original pathname, exactly as passed to the pathconf(3)
141 system call.
142 name The original name, exactly as passed to the pathconf(3) system
144 call.
145 explain_message_errno_pathconf
147 void explain_message_errno_pathconf(char *message, int message_size,
148 int errnum, const char *pathname, int name);
149 The explain_message_errno_pathconf function may be used to obtain an
151 explanation of an error returned by the pathconf(3) system call. The
152 least the message will contain is the value of strerror(errnum), but
153 usually it will do much better, and indicate the underlying cause in
154 more detail.
155 This function is intended to be used in a fashion similar to the fol‐
157 lowing example:
158 if (pathconf(pathname, name) < 0)
159 {
160 int err = errno;
161 char message[3000];
162 explain_message_errno_pathconf(message, sizeof(message), err,
163 pathname, name);
164 fprintf(stderr, "%s\n", message);
165 exit(EXIT_FAILURE);
166 }
167 The above code example is available pre‐packaged as the explain_path‐
169 conf_or_die(3) function.
170 message The location in which to store the returned message. If a
172 suitable message return buffer is supplied, this function is
173 thread safe.
174 message_size
176 The size in bytes of the location in which to store the
177 returned message.
178 errnum The error value to be decoded, usually obtained from the errno
180 global variable just before this function is called. This is
181 necessary if you need to call any code between the system call
182 to be explained and this function, because many libc functions
183 will alter the value of errno.
184 pathname
186 The original pathname, exactly as passed to the pathconf(3)
187 system call.
188 name The original name, exactly as passed to the pathconf(3) system
190 call.
191
193 pathconf(3)
194 get configuration values for files
195 explain_pathconf_or_die(3)
197 get configuration values for files and report errors
198
200 libexplain version 1.4
201 Copyright (C) 2008 Peter Miller
202 explain_pathconf(3)