1explain_tmpfile(3) Library Functions Manual explain_tmpfile(3)
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6 explain_tmpfile - explain tmpfile(3) errors
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9 #include <libexplain/tmpfile.h>
10 const char *explain_tmpfile(void);
11 const char *explain_errno_tmpfile(int errnum, void);
12 void explain_message_tmpfile(char *message, int message_size, void);
13 void explain_message_errno_tmpfile(char *message, int message_size, int
14 errnum, void);
15
17 These functions may be used to obtain explanations for errors returned
18 by the tmpfile(3) system call.
19 explain_tmpfile
21 const char *explain_tmpfile(void);
22 The explain_tmpfile function is used to obtain an explanation of an
24 error returned by the tmpfile(3) system call. The least the message
25 will contain is the value of strerror(errno), but usually it will do
26 much better, and indicate the underlying cause in more detail.
27 The errno global variable will be used to obtain the error value to be
29 decoded.
30 Returns:
32 The message explaining the error. This message buffer is shared
33 by all libexplain functions which do not supply a buffer in
34 their argument list. This will be overwritten by the next call
35 to any libexplain function which shares this buffer, including
36 other threads.
37 Note: This function is not thread safe, because it shares a return buf‐
39 fer across all threads, and many other functions in this library.
40 Example: This function is intended to be used in a fashion similar to
42 the following example:
43 FILE *result = tmpfile();
44 if (!result)
45 {
46 fprintf(stderr, "%s\n", explain_tmpfile());
47 exit(EXIT_FAILURE);
48 }
49 The above code example is available pre‐packaged as the explain_tmp‐
51 file_or_die(3) function.
52 explain_errno_tmpfile
54 const char *explain_errno_tmpfile(int errnum, void);
55 The explain_errno_tmpfile function is used to obtain an explanation of
57 an error returned by the tmpfile(3) system call. The least the message
58 will contain is the value of strerror(errno), but usually it will do
59 much better, and indicate the underlying cause in more detail.
60 errnum The error value to be decoded, usually obtained from the errno
62 global variable just before this function is called. This is
63 necessary if you need to call any code between the system call
64 to be explained and this function, because many libc functions
65 will alter the value of errno.
66 Returns:
68 The message explaining the error. This message buffer is shared
69 by all libexplain functions which do not supply a buffer in
70 their argument list. This will be overwritten by the next call
71 to any libexplain function which shares this buffer, including
72 other threads.
73 Note: This function is not thread safe, because it shares a return buf‐
75 fer across all threads, and many other functions in this library.
76 Example: This function is intended to be used in a fashion similar to
78 the following example:
79 FILE *result = tmpfile();
80 if (!result)
81 {
82 int err = errno;
83 fprintf(stderr, "%s\n", explain_errno_tmpfile(err, ));
84 exit(EXIT_FAILURE);
85 }
86 The above code example is available pre‐packaged as the explain_tmp‐
88 file_or_die(3) function.
89 explain_message_tmpfile
91 void explain_message_tmpfile(char *message, int message_size, void);
92 The explain_message_tmpfile function is used to obtain an explanation
94 of an error returned by the tmpfile(3) system call. The least the mes‐
95 sage will contain is the value of strerror(errno), but usually it will
96 do much better, and indicate the underlying cause in more detail.
97 The errno global variable will be used to obtain the error value to be
99 decoded.
100 message The location in which to store the returned message. If a suit‐
102 able message return buffer is supplied, this function is thread
103 safe.
104 message_size
106 The size in bytes of the location in which to store the
107 returned message.
108 Example: This function is intended to be used in a fashion similar to
110 the following example:
111 FILE *result = tmpfile();
112 if (!result)
113 {
114 char message[3000];
115 explain_message_tmpfile(message, sizeof(message), );
116 fprintf(stderr, "%s\n", message);
117 exit(EXIT_FAILURE);
118 }
119 The above code example is available pre‐packaged as the explain_tmp‐
121 file_or_die(3) function.
122 explain_message_errno_tmpfile
124 void explain_message_errno_tmpfile(char *message, int message_size, int
125 errnum, void);
126 The explain_message_errno_tmpfile function is used to obtain an expla‐
128 nation of an error returned by the tmpfile(3) system call. The least
129 the message will contain is the value of strerror(errno), but usually
130 it will do much better, and indicate the underlying cause in more
131 detail.
132 message The location in which to store the returned message. If a suit‐
134 able message return buffer is supplied, this function is thread
135 safe.
136 message_size
138 The size in bytes of the location in which to store the
139 returned message.
140 errnum The error value to be decoded, usually obtained from the errno
142 global variable just before this function is called. This is
143 necessary if you need to call any code between the system call
144 to be explained and this function, because many libc functions
145 will alter the value of errno.
146 Example: This function is intended to be used in a fashion similar to
148 the following example:
149 FILE *result = tmpfile();
150 if (!result)
151 {
152 int err = errno;
153 char message[3000];
154 explain_message_errno_tmpfile(message, sizeof(message), err,
155 );
156 fprintf(stderr, "%s\n", message);
157 exit(EXIT_FAILURE);
158 }
159 The above code example is available pre‐packaged as the explain_tmp‐
161 file_or_die(3) function.
162
164 tmpfile(3)
165 create a temporary file
166 explain_tmpfile_or_die(3)
168 create a temporary file and report errors
169
171 libexplain version 1.4
172 Copyright (C) 2009 Peter Miller
173 explain_tmpfile(3)