1explain_lstat(3) Library Functions Manual explain_lstat(3)
2
6 explain_lstat - explain lstat(3) errors
7
9 #include <libexplain/lstat.h>
10 const char *explain_lstat(const char *pathname, const struct stat
11 *buf);
12 void explain_message_lstat(char *message, int message_size, const char
13 *pathname, const struct stat *buf);
14 const char *explain_errno_lstat(int errnum, const char *pathname, const
15 struct stat *buf);
16 void explain_message_errno_lstat(char *message, int message_size, int
17 errnum, const char *pathname, const struct stat *buf);
18
20 These functions may be used to obtains explanations for lstat(2)
21 errors.
22 explain_lstat
24 const char *explain_lstat(const char *pathname, const struct stat
25 *buf);
26 The explain_lstat function is used to obtain an explanation of an error
28 returned by the lstat(2) function. The least the message will contain
29 is the value of strerror(errno), but usually it will do much better,
30 and indicate the underlying cause in more detail.
31 The errno global variable will be used to obtain the error value to be
33 decoded.
34 This function is intended to be used in a fashion similar to the fol‐
36 lowing example:
37 if (lstat(pathname, &buf) < 0)
38 {
39 fprintf(stderr, '%s0, explain_lstat(pathname, &buf));
40 exit(EXIT_FAILURE);
41 }
42 pathname
44 The original pathname, exactly as passed to the lstat(2) system
45 call.
46 buf The original buf, exactly as passed to the lstat(2) system
48 call.
49 Returns:
51 The message explaining the error. This message buffer is
52 shared by all libexplain functions which do not supply a buffer
53 in their argument list. This will be overwritten by the next
54 call to any libexplain function which shares this buffer,
55 including other threads.
56 Note: This function is not thread safe, because it shares a return buf‐
58 fer across all threads, and many other functions in this library.
59 explain_errno_lstat
61 "const char *explain_errno_lstat(int errnum, const char *pathname,
62 const struct stat *buf);
63 The explain_errno_lstat function is used to obtain an explanation of an
65 error returned by the lstat(2) function. The least the message will
66 contain is the value of strerror(errnum), but usually it will do much
67 better, and indicate the underlying cause in more detail.
68 This function is intended to be used in a fashion similar to the fol‐
70 lowing example:
71 if (lstat(pathname, &buf) < 0)
72 {
73 int err = errno;
74 fprintf(stderr, '%s0, explain_errno_lstat(err, pathname, &buf));
75 exit(EXIT_FAILURE);
76 }
77 errnum The error value to be decoded, usually obtained from the errno
79 global variable just before this function is called. This is
80 necessary if you need to call any code between the system call
81 to be explained and this function, because many libc functions
82 will alter the value of errno.
83 pathname
85 The original pathname, exactly as passed to the lstat(2) system
86 call.
87 buf The original buf, exactly as passed to the lstat(2) system
89 call.
90 Returns:
92 The message explaining the error. This message buffer is
93 shared by all libexplain functions which do not supply a buffer
94 in their argument list. This will be overwritten by the next
95 call to any libexplain function which shares this buffer,
96 including other threads.
97 Note: This function is not thread safe, because it shares a return buf‐
99 fer across all threads, and many other functions in this library.
100 explain_message_lstat
102 void explain_message_lstat(char *message, int message_size, const char
103 *pathname, const struct stat *buf);
104 The explain_message_lstat function is used to obtain an explanation of
106 an error returned by the lstat(2) function. The least the message will
107 contain is the value of strerror(errno), but usually it will do much
108 better, and indicate the underlying cause in more detail.
109 The errno global variable will be used to obtain the error value to be
111 decoded.
112 This function is intended to be used in a fashion similar to the fol‐
114 lowing example:
115 if (lstat(pathname, &buf) < 0)
116 {
117 char message[3000];
118 explain_message_lstat(message, sizeof(message), pathname, &buf);
119 fprintf(stderr, '%s0, message);
120 exit(EXIT_FAILURE);
121 }
122 message The location in which to store the returned message. Because a
124 message return buffer has been supplied, this function is
125 thread safe.
126 message_size
128 The size in bytes of the location in which to store the
129 returned message.
130 pathname
132 The original pathname, exactly as passed to the lstat(2) system
133 call.
134 buf The original buf, exactly as passed to the lstat(2) system
136 call.
137 explain_message_errno_lstat
139 void explain_message_errno_lstat(char *message, int message_size, int
140 errnum, const char *pathname, const struct stat *buf);
141 The explain_message_errno_lstat function is used to obtain an explana‐
143 tion of an error returned by the lstat(2) function. The least the mes‐
144 sage will contain is the value of strerror(errnum), but usually it will
145 do much better, and indicate the underlying cause in more detail.
146 This function is intended to be used in a fashion similar to the fol‐
148 lowing example:
149 if (lstat(pathname, &buf) < 0)
150 {
151 int err = errno;
152 char message[3000];
153 explain_message_errno_lstat(message, sizeof(message), err,
154 pathname, &buf);
155 fprintf(stderr, '%s0, message);
156 exit(EXIT_FAILURE);
157 }
158 message The location in which to store the returned message. Because a
160 message return buffer has been supplied, this function is
161 thread safe.
162 message_size
164 The size in bytes of the location in which to store the
165 returned message.
166 errnum The error value to be decoded, usually obtained from the errno
168 global variable just before this function is called. This is
169 necessary if you need to call any code between the system call
170 to be explained and this function, because many libc functions
171 will alter the value of errno.
172 pathname
174 The original pathname, exactly as passed to the lstat(2) system
175 call.
176 buf The original buf, exactly as passed to the lstat(2) system
178 call.
179
181 libexplain version 1.4
182 Copyright (C) 2008 Peter Miller
183
185 Written by Peter Miller <pmiller@opensource.org.au>
186 explain_lstat(3)