1explain_strtoull(3) Library Functions Manual explain_strtoull(3)
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6 explain_strtoull - explain strtoull(3) errors
7
9 #include <libexplain/strtoull.h>
10 const char *explain_strtoull(const char *nptr, char **endptr, int
11 base);
12 const char *explain_errno_strtoull(int errnum, const char *nptr, char
13 **endptr, int base);
14 void explain_message_strtoull(char *message, int message_size, const
15 char *nptr, char **endptr, int base);
16 void explain_message_errno_strtoull(char *message, int message_size,
17 int errnum, const char *nptr, char **endptr, int base);
18
20 These functions may be used to obtain explanations for errors returned
21 by the strtoull(3) system call.
22 explain_strtoull
24 const char *explain_strtoull(const char *nptr, char **endptr, int
25 base);
26 The explain_strtoull function is used to obtain an explanation of an
28 error returned by the strtoull(3) system call. The least the message
29 will contain is the value of strerror(errno), but usually it will do
30 much better, 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 nptr The original nptr, exactly as passed to the strtoull(3) system
36 call.
37 endptr The original endptr, exactly as passed to the strtoull(3) sys‐
39 tem call.
40 base The original base, exactly as passed to the strtoull(3) system
42 call.
43 Returns:
45 The message explaining the error. This message buffer is shared
46 by all libexplain functions which do not supply a buffer in
47 their argument list. This will be overwritten by the next call
48 to any libexplain function which shares this buffer, including
49 other threads.
50 Note: This function is not thread safe, because it shares a return buf‐
52 fer across all threads, and many other functions in this library.
53 Example: This function is intended to be used in a fashion similar to
55 the following example:
56 unsigned long long result = strtoull(nptr, endptr, base);
57 if (result < 0)
58 {
59 fprintf(stderr, "%s\n", explain_strtoull(nptr, endptr,
60 base));
61 exit(EXIT_FAILURE);
62 }
63 The above code example is available pre‐packaged as the explain_str‐
65 toull_or_die(3) function.
66 explain_errno_strtoull
68 const char *explain_errno_strtoull(int errnum, const char *nptr, char
69 **endptr, int base);
70 The explain_errno_strtoull function is used to obtain an explanation of
72 an error returned by the strtoull(3) system call. The least the mes‐
73 sage will contain is the value of strerror(errno), but usually it will
74 do much better, and indicate the underlying cause in more detail.
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 nptr The original nptr, exactly as passed to the strtoull(3) system
83 call.
84 endptr The original endptr, exactly as passed to the strtoull(3) sys‐
86 tem call.
87 base The original base, exactly as passed to the strtoull(3) system
89 call.
90 Returns:
92 The message explaining the error. This message buffer is shared
93 by all libexplain functions which do not supply a buffer in
94 their argument list. This will be overwritten by the next call
95 to any libexplain function which shares this buffer, including
96 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 Example: This function is intended to be used in a fashion similar to
102 the following example:
103 unsigned long long result = strtoull(nptr, endptr, base);
104 if (result < 0)
105 {
106 int err = errno;
107 fprintf(stderr, "%s\n", explain_errno_strtoull(err, nptr,
108 endptr, base));
109 exit(EXIT_FAILURE);
110 }
111 The above code example is available pre‐packaged as the explain_str‐
113 toull_or_die(3) function.
114 explain_message_strtoull
116 void explain_message_strtoull(char *message, int message_size, const
117 char *nptr, char **endptr, int base);
118 The explain_message_strtoull function is used to obtain an explanation
120 of an error returned by the strtoull(3) system call. The least the
121 message will contain is the value of strerror(errno), but usually it
122 will do much better, and indicate the underlying cause in more detail.
123 The errno global variable will be used to obtain the error value to be
125 decoded.
126 message The location in which to store the returned message. If a suit‐
128 able message return buffer is supplied, this function is thread
129 safe.
130 message_size
132 The size in bytes of the location in which to store the
133 returned message.
134 nptr The original nptr, exactly as passed to the strtoull(3) system
136 call.
137 endptr The original endptr, exactly as passed to the strtoull(3) sys‐
139 tem call.
140 base The original base, exactly as passed to the strtoull(3) system
142 call.
143 Example: This function is intended to be used in a fashion similar to
145 the following example:
146 unsigned long long result = strtoull(nptr, endptr, base);
147 if (result < 0)
148 {
149 char message[3000];
150 explain_message_strtoull(message, sizeof(message), nptr,
151 endptr, base);
152 fprintf(stderr, "%s\n", message);
153 exit(EXIT_FAILURE);
154 }
155 The above code example is available pre‐packaged as the explain_str‐
157 toull_or_die(3) function.
158 explain_message_errno_strtoull
160 void explain_message_errno_strtoull(char *message, int message_size,
161 int errnum, const char *nptr, char **endptr, int base);
162 The explain_message_errno_strtoull function is used to obtain an expla‐
164 nation of an error returned by the strtoull(3) system call. The least
165 the message will contain is the value of strerror(errno), but usually
166 it will do much better, and indicate the underlying cause in more
167 detail.
168 message The location in which to store the returned message. If a suit‐
170 able message return buffer is supplied, this function is thread
171 safe.
172 message_size
174 The size in bytes of the location in which to store the
175 returned message.
176 errnum The error value to be decoded, usually obtained from the errno
178 global variable just before this function is called. This is
179 necessary if you need to call any code between the system call
180 to be explained and this function, because many libc functions
181 will alter the value of errno.
182 nptr The original nptr, exactly as passed to the strtoull(3) system
184 call.
185 endptr The original endptr, exactly as passed to the strtoull(3) sys‐
187 tem call.
188 base The original base, exactly as passed to the strtoull(3) system
190 call.
191 Example: This function is intended to be used in a fashion similar to
193 the following example:
194 unsigned long long result = strtoull(nptr, endptr, base);
195 if (result < 0)
196 {
197 int err = errno;
198 char message[3000];
199 explain_message_errno_strtoull(message, sizeof(message),
200 err, nptr, endptr, base);
201 fprintf(stderr, "%s\n", message);
202 exit(EXIT_FAILURE);
203 }
204 The above code example is available pre‐packaged as the explain_str‐
206 toull_or_die(3) function.
207
209 strtoull(3)
210 convert a string to an unsigned long integer
211 explain_strtoull_or_die(3)
213 convert a string to an unsigned long integer and report errors
214
216 libexplain version 1.4
217 Copyright (C) 2009 Peter Miller
218 explain_strtoull(3)