1explain_utimes(3)          Library Functions Manual          explain_utimes(3)
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NAME

6       explain_utimes - explain utimes(2) errors
7

SYNOPSIS

9       #include <libexplain/utimes.h>
10       const char *explain_utimes(const char *pathname, const struct timeval
11       *data);
12       const char *explain_errno_utimes(int errnum, const char *pathname,
13       const struct timeval *data);
14       void explain_message_utimes(char *message, int message_size, const char
15       *pathname, const struct timeval *data);
16       void explain_message_errno_utimes(char *message, int message_size, int
17       errnum, const char *pathname, const struct timeval *data);
18

DESCRIPTION

20       These  functions may be used to obtain explanations for errors returned
21       by the utimes(2) system call.
22
23   explain_utimes
24       const char *explain_utimes(const char *pathname, const struct timeval
25       *data);
26
27       The  explain_utimes  function  is  used  to obtain an explanation of an
28       error returned by the utimes(2) system call. The least the message will
29       contain  is  the  value of strerror(errno), but usually it will do much
30       better, and indicate the underlying cause in more detail.
31
32       The errno global variable will be used to obtain the error value to  be
33       decoded.
34
35       pathname
36               The  original pathname, exactly as passed to the utimes(2) sys‐
37               tem call.
38
39       data    The original data, exactly as passed to  the  utimes(2)  system
40               call.
41
42       Returns:
43               The message explaining the error. This message buffer is shared
44               by all libexplain functions which do not  supply  a  buffer  in
45               their argument list.  This will be overwritten by the next call
46               to any libexplain function which shares this buffer,  including
47               other threads.
48
49       Note: This function is not thread safe, because it shares a return buf‐
50       fer across all threads, and many other functions in this library.
51
52       Example: This function is intended to be used in a fashion  similar  to
53       the following example:
54              if (utimes(pathname, data) < 0)
55              {
56                  fprintf(stderr, "%s\n", explain_utimes(pathname, data));
57                  exit(EXIT_FAILURE);
58              }
59
60       The   above   code   example   is   available   pre‐packaged   as   the
61       explain_utimes_or_die(3) function.
62
63   explain_errno_utimes
64       const char *explain_errno_utimes(int errnum, const char *pathname,
65       const struct timeval *data);
66
67       The  explain_errno_utimes  function is used to obtain an explanation of
68       an error returned by the utimes(2) system call. The least  the  message
69       will  contain  is  the value of strerror(errno), but usually it will do
70       much better, and indicate the underlying cause in more detail.
71
72       errnum  The error value to be decoded, usually obtained from the  errno
73               global  variable  just  before this function is called. This is
74               necessary if you need to call any code between the system  call
75               to  be explained and this function, because many libc functions
76               will alter the value of errno.
77
78       pathname
79               The original pathname, exactly as passed to the utimes(2)  sys‐
80               tem call.
81
82       data    The  original  data,  exactly as passed to the utimes(2) system
83               call.
84
85       Returns:
86               The message explaining the error. This message buffer is shared
87               by  all  libexplain  functions  which do not supply a buffer in
88               their argument list.  This will be overwritten by the next call
89               to  any libexplain function which shares this buffer, including
90               other threads.
91
92       Note: This function is not thread safe, because it shares a return buf‐
93       fer across all threads, and many other functions in this library.
94
95       Example:  This  function is intended to be used in a fashion similar to
96       the following example:
97              if (utimes(pathname, data) < 0)
98              {
99                  int err = errno;
100                  fprintf(stderr, "%s\n", explain_errno_utimes(err, pathname,
101                  data));
102                  exit(EXIT_FAILURE);
103              }
104
105       The   above   code   example   is   available   pre‐packaged   as   the
106       explain_utimes_or_die(3) function.
107
108   explain_message_utimes
109       void explain_message_utimes(char *message, int message_size, const char
110       *pathname, const struct timeval *data);
111
112       The explain_message_utimes function is used to obtain an explanation of
113       an error returned by the utimes(2) system call. The least  the  message
114       will  contain  is  the value of strerror(errno), but usually it will do
115       much better, and indicate the underlying cause in more detail.
116
117       The errno global variable will be used to obtain the error value to  be
118       decoded.
119
120       message The location in which to store the returned message. If a suit‐
121               able message return buffer is supplied, this function is thread
122               safe.
123
124       message_size
125               The  size  in  bytes  of  the  location  in  which to store the
126               returned message.
127
128       pathname
129               The original pathname, exactly as passed to the utimes(2)  sys‐
130               tem call.
131
132       data    The  original  data,  exactly as passed to the utimes(2) system
133               call.
134
135       Example: This function is intended to be used in a fashion  similar  to
136       the following example:
137              if (utimes(pathname, data) < 0)
138              {
139                  char message[3000];
140                  explain_message_utimes(message, sizeof(message), pathname,
141                  data);
142                  fprintf(stderr, "%s\n", message);
143                  exit(EXIT_FAILURE);
144              }
145
146       The   above   code   example   is   available   pre‐packaged   as   the
147       explain_utimes_or_die(3) function.
148
149   explain_message_errno_utimes
150       void explain_message_errno_utimes(char *message, int message_size, int
151       errnum, const char *pathname, const struct timeval *data);
152
153       The explain_message_errno_utimes function is used to obtain an explana‐
154       tion  of  an error returned by the utimes(2) system call. The least the
155       message will contain is the value of strerror(errno),  but  usually  it
156       will do much better, and indicate the underlying cause in more detail.
157
158       message The location in which to store the returned message. If a suit‐
159               able message return buffer is supplied, this function is thread
160               safe.
161
162       message_size
163               The  size  in  bytes  of  the  location  in  which to store the
164               returned message.
165
166       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
172       pathname
173               The original pathname, exactly as passed to the utimes(2)  sys‐
174               tem call.
175
176       data    The  original  data,  exactly as passed to the utimes(2) system
177               call.
178
179       Example: This function is intended to be used in a fashion  similar  to
180       the following example:
181              if (utimes(pathname, data) < 0)
182              {
183                  int err = errno;
184                  char message[3000];
185                  explain_message_errno_utimes(message, sizeof(message), err,
186                  pathname, data);
187                  fprintf(stderr, "%s\n", message);
188                  exit(EXIT_FAILURE);
189              }
190
191       The   above   code   example   is   available   pre‐packaged   as   the
192       explain_utimes_or_die(3) function.
193

SEE ALSO

195       utimes(2)
196               change file last access and modification times
197
198       explain_utimes_or_die(3)
199               change  file  last  access  and  modification  times and report
200               errors
201
203       libexplain version 0.40
204       Copyright (C) 2010 Peter Miller
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207
208                                                             explain_utimes(3)
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