1explain_rename(3) Library Functions Manual explain_rename(3)
2
6 explain_rename - explain rename(2) errors
7
9 #include <libexplain/rename.h>
10 const char *explain_rename(const char *oldpath, const char *newpath);
11 const char *explain_errno_rename(int errnum, const char *oldpath, const
12 char *newpath);
13 void explain_message_rename(char *message, int message_size, const char
14 *oldpath, const char *newpath);
15 void explain_message_errno_rename(char *message, int message_size, int
16 errnum, const char *oldpath, const char *newpath);
17
19 The functions declared in the <libexplain/rename.h> include file may be
20 used to explain errors returned by the rename(2) system call.
21 explain_rename
23 const char *explain_rename(const char *oldpath, const char *newpath);
24 The explain_rename function is used to obtain an explanation of an
26 error returned by the rename(2) function. 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 This function is intended to be used in a fashion similar to the fol‐
34 lowing example:
35 if (rename(oldpath, rewpath) < 0)
36 {
37 fprintf(stderr, "%s\n", explain_rename(oldpath, newpath));
38 exit(EXIT_FAILURE);
39 }
40 oldpath The original oldpath, exactly as passed to the rename(2) system
42 call.
43 newpath The original newpath, exactly as passed to the rename(2) system
45 call.
46 Returns:
48 The message explaining the error. This message buffer is
49 shared by all libexplain functions which do not supply a buffer
50 in their argument list. This will be overwritten by the next
51 call to any libexplain function which shares this buffer,
52 including other threads.
53 Note: This function is not thread safe, because it shares a return buf‐
55 fer across all threads, and many other functions in this library.
56 explain_errno_rename
58 const char *explain_errno_rename(int errnum, const char *oldpath, const
59 char *newpath);
60 The explain_errno_rename function is used to obtain an explanation of
62 an error returned by the rename(2) function. The least the message
63 will contain is the value of strerror(errnum), but usually it will do
64 much better, and indicate the underlying cause in more detail.
65 This function is intended to be used in a fashion similar to the fol‐
67 lowing example:
68 if (rename(oldpath, newpath) < 0)
69 {
70 int err = errno;
71 fprintf(stderr, "%s\n", explain_errno_rename(err, oldpath,
72 newpath));
73 exit(EXIT_FAILURE);
74 }
75 errnum The error value to be decoded, usually obtained from the errno
77 global variable just before this function is called. This is
78 necessary if you need to call any code between the system call
79 to be explained and this function, because many libc functions
80 will alter the value of errno.
81 oldpath The original oldpath, exactly as passed to the rename(2) system
83 call.
84 newpath The original newpath, exactly as passed to the rename(2) system
86 call.
87 Returns:
89 The message explaining the error. This message buffer is
90 shared by all libexplain functions which do not supply a buffer
91 in their argument list. This will be overwritten by the next
92 call to any libexplain function which shares this buffer,
93 including other threads.
94 Note: This function is not thread safe, because it shares a return buf‐
96 fer across all threads, and many other functions in this library.
97 explain_message_rename
99 void explain_message_rename(char *message, int message_size, const char
100 *oldpath, const char *newpath);
101 The explain_message_rename function is used to obtain an explanation of
103 an error returned by the rename(2) function. The least the message
104 will contain is the value of strerror(errno), but usually it will do
105 much better, and indicate the underlying cause in more detail.
106 The errno global variable will be used to obtain the error value to be
108 decoded.
109 This function is intended to be used in a fashion similar to the fol‐
111 lowing example:
112 if (rename(oldpath, newpath) < 0)
113 {
114 char message[3000];
115 explain_message_rename(message, sizeof(message), oldpath,
116 newpath);
117 fprintf(stderr, "%s\n", message);
118 exit(EXIT_FAILURE);
119 }
120 message The location in which to store the returned message. Because a
122 message return buffer has been supplied, this function is
123 thread safe, if the buffer is thread safe.
124 message_size
126 The size in bytes of the location in which to store the
127 returned message.
128 oldpath The original oldpath, exactly as passed to the rename(2) system
130 call.
131 newpath The original newpath, exactly as passed to the rename(2) system
133 call.
134 explain_message_errno_rename
136 void explain_message_errno_rename(char *message, int message_size, int
137 errnum, const char *oldpath, const char *newpath);
138 The explain_message_errno_rename function is used to obtain an explana‐
140 tion of an error returned by the rename(2) function. The least the
141 message will contain is the value of strerror(errnum), but usually it
142 will do much better, and indicate the underlying cause in more detail.
143 This function is intended to be used in a fashion similar to the fol‐
145 lowing example:
146 if (rename(oldpath, newpath) < 0)
147 {
148 int err = errno;
149 char message[3000];
150 explain_message_errno_rename(message, sizeof(message), err,
151 oldpath, newpath);
152 fprintf(stderr, "%s\n", message);
153 exit(EXIT_FAILURE);
154 }
155 message The location in which to store the returned message. Because a
157 message return buffer has been supplied, this function is
158 thread safe, given a thread safe buffer.
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 oldpath The original oldpath, exactly as passed to the rename(2) system
171 call.
172 newpath The original newpath, exactly as passed to the rename(2) system
174 call.
175
177 libexplain version 0.40
178 Copyright (C) 2008 Peter Miller
179
181 Written by Peter Miller <pmiller@opensource.org.au>
182 explain_rename(3)