1explain_tmpnam(3) Library Functions Manual explain_tmpnam(3)
2
6 explain_tmpnam - explain tmpnam(3) errors
7
9 #include <libexplain/tmpnam.h>
10 const char *explain_tmpnam(char *pathname);
11 const char *explain_errno_tmpnam(int errnum, char *pathname);
12 void explain_message_tmpnam(char *message, int message_size, char
13 *pathname);
14 void explain_message_errno_tmpnam(char *message, int message_size, int
15 errnum, char *pathname);
16
18 These functions may be used to obtain explanations for errors returned
19 by the tmpnam(3) system call.
20 explain_tmpnam
22 const char *explain_tmpnam(char *pathname);
23 The explain_tmpnam function is used to obtain an explanation of an
25 error returned by the tmpnam(3) system call. The least the message will
26 contain is the value of strerror(errno), but usually it will do much
27 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 pathname
33 The original pathname, exactly as passed to the tmpnam(3) sys‐
34 tem call.
35 Returns:
37 The message explaining the error. This message buffer is shared
38 by all libexplain functions which do not supply a buffer in
39 their argument list. This will be overwritten by the next call
40 to any libexplain function which shares this buffer, including
41 other threads.
42 Note: This function is not thread safe, because it shares a return buf‐
44 fer across all threads, and many other functions in this library.
45 Example: This function is intended to be used in a fashion similar to
47 the following example:
48 char *result = tmpnam(pathname);
49 if (!result)
50 {
51 fprintf(stderr, "%s\n", explain_tmpnam(pathname));
52 exit(EXIT_FAILURE);
53 }
54 The above code example is available pre‐packaged as the explain_tmp‐
56 nam_or_die(3) function.
57 explain_errno_tmpnam
59 const char *explain_errno_tmpnam(int errnum, char *pathname);
60 The explain_errno_tmpnam function is used to obtain an explanation of
62 an error returned by the tmpnam(3) system call. The least the message
63 will contain is the value of strerror(errno), but usually it will do
64 much better, and indicate the underlying cause in more detail.
65 errnum The error value to be decoded, usually obtained from the errno
67 global variable just before this function is called. This is
68 necessary if you need to call any code between the system call
69 to be explained and this function, because many libc functions
70 will alter the value of errno.
71 pathname
73 The original pathname, exactly as passed to the tmpnam(3) sys‐
74 tem call.
75 Returns:
77 The message explaining the error. This message buffer is shared
78 by all libexplain functions which do not supply a buffer in
79 their argument list. This will be overwritten by the next call
80 to any libexplain function which shares this buffer, including
81 other threads.
82 Note: This function is not thread safe, because it shares a return buf‐
84 fer across all threads, and many other functions in this library.
85 Example: This function is intended to be used in a fashion similar to
87 the following example:
88 char *result = tmpnam(pathname);
89 if (!result)
90 {
91 int err = errno;
92 fprintf(stderr, "%s\n", explain_errno_tmpnam(err, path‐
93 name));
94 exit(EXIT_FAILURE);
95 }
96 The above code example is available pre‐packaged as the explain_tmp‐
98 nam_or_die(3) function.
99 explain_message_tmpnam
101 void explain_message_tmpnam(char *message, int message_size, char
102 *pathname);
103 The explain_message_tmpnam function is used to obtain an explanation of
105 an error returned by the tmpnam(3) system call. The least the message
106 will contain is the value of strerror(errno), but usually it will do
107 much better, and indicate the underlying cause in more detail.
108 The errno global variable will be used to obtain the error value to be
110 decoded.
111 message The location in which to store the returned message. If a suit‐
113 able message return buffer is supplied, this function is thread
114 safe.
115 message_size
117 The size in bytes of the location in which to store the
118 returned message.
119 pathname
121 The original pathname, exactly as passed to the tmpnam(3) sys‐
122 tem call.
123 Example: This function is intended to be used in a fashion similar to
125 the following example:
126 char *result = tmpnam(pathname);
127 if (!result)
128 {
129 char message[3000];
130 explain_message_tmpnam(message, sizeof(message), pathname);
131 fprintf(stderr, "%s\n", message);
132 exit(EXIT_FAILURE);
133 }
134 The above code example is available pre‐packaged as the explain_tmp‐
136 nam_or_die(3) function.
137 explain_message_errno_tmpnam
139 void explain_message_errno_tmpnam(char *message, int message_size, int
140 errnum, char *pathname);
141 The explain_message_errno_tmpnam function is used to obtain an explana‐
143 tion of an error returned by the tmpnam(3) system call. The least the
144 message will contain is the value of strerror(errno), but usually it
145 will do much better, and indicate the underlying cause in 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 pathname
162 The original pathname, exactly as passed to the tmpnam(3) sys‐
163 tem call.
164 Example: This function is intended to be used in a fashion similar to
166 the following example:
167 char *result = tmpnam(pathname);
168 if (!result)
169 {
170 int err = errno;
171 char message[3000];
172 explain_message_errno_tmpnam(message, sizeof(message), err,
173 pathname);
174 fprintf(stderr, "%s\n", message);
175 exit(EXIT_FAILURE);
176 }
177 The above code example is available pre‐packaged as the explain_tmp‐
179 nam_or_die(3) function.
180
182 tmpnam(3)
183 create a name for a temporary file
184 explain_tmpnam_or_die(3)
186 create a name for a temporary file and report errors
187
189 libexplain version 0.40
190 Copyright (C) 2010 Peter Miller
191 explain_tmpnam(3)