1explain_creat(3) Library Functions Manual explain_creat(3)
2
6 explain_creat - explain creat(2) errors
7
9 #include <libexplain/creat.h>
10 const char *explain_creat(const char *pathname, int mode);
11 const char *explain_errno_creat(int errnum, const char *pathname, int
12 mode);
13 void explain_message_creat(char *message, int message_size, const char
14 *pathname, int mode);
15 void explain_message_errno_creat(char *message, int message_size, int
16 errnum, const char *pathname, int mode);
17
19 These functions may be used to obtain explanations for errors returned
20 by the creat(2) system call.
21 explain_creat
23 const char *explain_creat(const char *pathname, int mode);
24 The explain_creat function is used to obtain an explanation of an error
26 returned by the creat(2) system call. The least the message will con‐
27 tain is the value of strerror(errno), but usually it will do much bet‐
28 ter, 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 (creat(pathname, mode) < 0)
36 {
37 fprintf(stderr, "%s\n", explain_creat(pathname, mode));
38 exit(EXIT_FAILURE);
39 }
40 pathname
42 The original pathname, exactly as passed to the creat(2) system
43 call.
44 mode The original mode, exactly as passed to the creat(2) system
46 call.
47 Returns:
49 The message explaining the error. This message buffer is
50 shared by all libexplain functions which do not supply a buffer
51 in their argument list. This will be overwritten by the next
52 call to any libexplain function which shares this buffer,
53 including other threads.
54 Note: This function is not thread safe, because it shares a return buf‐
56 fer across all threads, and many other functions in this library.
57 explain_errno_creat
59 const char *explain_errno_creat(int errnum, const char *pathname, int
60 mode);
61 The explain_errno_creat function is used to obtain an explanation of an
63 error returned by the creat(2) system call. The least the message will
64 contain is the value of strerror(errnum), but usually it will do much
65 better, and indicate the underlying cause in more detail.
66 This function is intended to be used in a fashion similar to the fol‐
68 lowing example:
69 if (creat(pathname, mode) < 0)
70 {
71 int err = errno;
72 fprintf(stderr, "%s\n", explain_errno_creat(err, pathname, mode));
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 pathname
83 The original pathname, exactly as passed to the creat(2) system
84 call.
85 mode The original mode, exactly as passed to the creat(2) system
87 call.
88 Returns:
90 The message explaining the error. This message buffer is
91 shared by all libexplain functions which do not supply a buffer
92 in their argument list. This will be overwritten by the next
93 call to any libexplain function which shares this buffer,
94 including other threads.
95 Note: This function is not thread safe, because it shares a return buf‐
97 fer across all threads, and many other functions in this library.
98 explain_message_creat
100 void explain_message_creat(char *message, int message_size, const char
101 *pathname, int mode);
102 The explain_message_creat function may be used to obtain an explana‐
104 tion of an error returned by the creat(2) system call. The least the
105 message will contain is the value of strerror(errno), but usually it
106 will do much better, and indicate the underlying cause in more detail.
107 The errno global variable will be used to obtain the error value to be
109 decoded.
110 This function is intended to be used in a fashion similar to the fol‐
112 lowing example:
113 if (creat(pathname, mode) < 0)
114 {
115 char message[3000];
116 explain_message_creat(message, sizeof(message), pathname, mode);
117 fprintf(stderr, "%s\n", message);
118 exit(EXIT_FAILURE);
119 }
120 message The location in which to store the returned message. If a
122 suitable message return buffer is supplied, this function is
123 thread safe.
124 message_size
126 The size in bytes of the location in which to store the
127 returned message.
128 pathname
130 The original pathname, exactly as passed to the creat(2) system
131 call.
132 mode The original mode, exactly as passed to the creat(2) system
134 call.
135 explain_message_errno_creat
137 void explain_message_errno_creat(char *message, int message_size, int
138 errnum, const char *pathname, int mode);
139 The explain_message_errno_creat function may be used to obtain an
141 explanation of an error returned by the creat(2) system call. The
142 least the message will contain is the value of strerror(errnum), but
143 usually it will do much better, and indicate the underlying cause in
144 more detail.
145 This function is intended to be used in a fashion similar to the fol‐
147 lowing example:
148 if (creat(pathname, mode) < 0)
149 {
150 int err = errno;
151 char message[3000];
152 explain_message_errno_creat(message, sizeof(message), err, pathname,
153 mode);
154 fprintf(stderr, "%s\n", message);
155 exit(EXIT_FAILURE);
156 }
157 message The location in which to store the returned message. If a
159 suitable message return buffer is supplied, this function is
160 thread safe.
161 message_size
163 The size in bytes of the location in which to store the
164 returned message.
165 errnum The error value to be decoded, usually obtained from the errno
167 global variable just before this function is called. This is
168 necessary if you need to call any code between the system call
169 to be explained and this function, because many libc functions
170 will alter the value of errno.
171 pathname
173 The original pathname, exactly as passed to the creat(2) system
174 call.
175 mode The original mode, exactly as passed to the creat(2) system
177 call.
178
180 creat(2)
181 open and possibly create a file or device
182 explain_creat_or_die(3)
184 create and open a file and report errors
185
187 libexplain version 0.40
188 Copyright (C) 2008 Peter Miller
189 explain_creat(3)