1explain_strtold(3) Library Functions Manual explain_strtold(3)
2
6 explain_strtold - explain strtold(3) errors
7
9 #include <libexplain/strtold.h>
10 const char *explain_strtold(const char *nptr, char **endptr);
11 const char *explain_errno_strtold(int errnum, const char *nptr, char
12 **endptr);
13 void explain_message_strtold(char *message, int message_size, const
14 char *nptr, char **endptr);
15 void explain_message_errno_strtold(char *message, int message_size, int
16 errnum, const char *nptr, char **endptr);
17
19 These functions may be used to obtain explanations for errors returned
20 by the strtold(3) system call.
21 explain_strtold
23 const char *explain_strtold(const char *nptr, char **endptr);
24 The explain_strtold function is used to obtain an explanation of an
26 error returned by the strtold(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 nptr The original nptr, exactly as passed to the strtold(3) system
34 call.
35 endptr The original endptr, exactly as passed to the strtold(3) system
37 call.
38 Returns:
40 The message explaining the error. This message buffer is shared
41 by all libexplain functions which do not supply a buffer in
42 their argument list. This will be overwritten by the next call
43 to any libexplain function which shares this buffer, including
44 other threads.
45 Note: This function is not thread safe, because it shares a return buf‐
47 fer across all threads, and many other functions in this library.
48 Example: This function is intended to be used in a fashion similar to
50 the following example:
51 long double result = strtold(nptr, endptr);
52 if (result < 0)
53 {
54 fprintf(stderr, "%s\n", explain_strtold(nptr, endptr));
55 exit(EXIT_FAILURE);
56 }
57 The above code example is available pre‐packaged as the explain_str‐
59 told_or_die(3) function.
60 explain_errno_strtold
62 const char *explain_errno_strtold(int errnum, const char *nptr, char
63 **endptr);
64 The explain_errno_strtold function is used to obtain an explanation of
66 an error returned by the strtold(3) system call. The least the message
67 will contain is the value of strerror(errno), but usually it will do
68 much better, and indicate the underlying cause in more detail.
69 errnum The error value to be decoded, usually obtained from the errno
71 global variable just before this function is called. This is
72 necessary if you need to call any code between the system call
73 to be explained and this function, because many libc functions
74 will alter the value of errno.
75 nptr The original nptr, exactly as passed to the strtold(3) system
77 call.
78 endptr The original endptr, exactly as passed to the strtold(3) system
80 call.
81 Returns:
83 The message explaining the error. This message buffer is shared
84 by all libexplain functions which do not supply a buffer in
85 their argument list. This will be overwritten by the next call
86 to any libexplain function which shares this buffer, including
87 other threads.
88 Note: This function is not thread safe, because it shares a return buf‐
90 fer across all threads, and many other functions in this library.
91 Example: This function is intended to be used in a fashion similar to
93 the following example:
94 long double result = strtold(nptr, endptr);
95 if (result < 0)
96 {
97 int err = errno;
98 fprintf(stderr, "%s\n", explain_errno_strtold(err, nptr,
99 endptr));
100 exit(EXIT_FAILURE);
101 }
102 The above code example is available pre‐packaged as the explain_str‐
104 told_or_die(3) function.
105 explain_message_strtold
107 void explain_message_strtold(char *message, int message_size, const
108 char *nptr, char **endptr);
109 The explain_message_strtold function is used to obtain an explanation
111 of an error returned by the strtold(3) system call. The least the mes‐
112 sage will contain is the value of strerror(errno), but usually it will
113 do much better, and indicate the underlying cause in more detail.
114 The errno global variable will be used to obtain the error value to be
116 decoded.
117 message The location in which to store the returned message. If a suit‐
119 able message return buffer is supplied, this function is thread
120 safe.
121 message_size
123 The size in bytes of the location in which to store the
124 returned message.
125 nptr The original nptr, exactly as passed to the strtold(3) system
127 call.
128 endptr The original endptr, exactly as passed to the strtold(3) system
130 call.
131 Example: This function is intended to be used in a fashion similar to
133 the following example:
134 long double result = strtold(nptr, endptr);
135 if (result < 0)
136 {
137 char message[3000];
138 explain_message_strtold(message, sizeof(message), nptr,
139 endptr);
140 fprintf(stderr, "%s\n", message);
141 exit(EXIT_FAILURE);
142 }
143 The above code example is available pre‐packaged as the explain_str‐
145 told_or_die(3) function.
146 explain_message_errno_strtold
148 void explain_message_errno_strtold(char *message, int message_size, int
149 errnum, const char *nptr, char **endptr);
150 The explain_message_errno_strtold function is used to obtain an expla‐
152 nation of an error returned by the strtold(3) system call. The least
153 the message will contain is the value of strerror(errno), but usually
154 it will do much better, and indicate the underlying cause in more
155 detail.
156 message The location in which to store the returned message. If a suit‐
158 able message return buffer is supplied, this function is thread
159 safe.
160 message_size
162 The size in bytes of the location in which to store the
163 returned message.
164 errnum The error value to be decoded, usually obtained from the errno
166 global variable just before this function is called. This is
167 necessary if you need to call any code between the system call
168 to be explained and this function, because many libc functions
169 will alter the value of errno.
170 nptr The original nptr, exactly as passed to the strtold(3) system
172 call.
173 endptr The original endptr, exactly as passed to the strtold(3) system
175 call.
176 Example: This function is intended to be used in a fashion similar to
178 the following example:
179 long double result = strtold(nptr, endptr);
180 if (result < 0)
181 {
182 int err = errno;
183 char message[3000];
184 explain_message_errno_strtold(message, sizeof(message), err,
185 nptr, endptr);
186 fprintf(stderr, "%s\n", message);
187 exit(EXIT_FAILURE);
188 }
189 The above code example is available pre‐packaged as the explain_str‐
191 told_or_die(3) function.
192
194 strtold(3)
195 convert ASCII string to floating‐point number
196 explain_strtold_or_die(3)
198 convert ASCII string to floating‐point number and report errors
199
201 libexplain version 0.40
202 Copyright (C) 2009 Peter Miller
203 explain_strtold(3)