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

6       explain_utime - explain utime(2) errors
7

SYNOPSIS

9       #include <libexplain/utime.h>
10       const  char  *explain_utime(const  char *pathname, const struct utimbuf
11       *times);
12       const char *explain_errno_utime(int errnum, const char *pathname, const
13       struct utimbuf *times);
14       void  explain_message_utime(char *message, int message_size, const char
15       *pathname, const struct utimbuf *times);
16       void explain_message_errno_utime(char *message, int  message_size,  int
17       errnum, const char *pathname, const struct utimbuf *times);
18

DESCRIPTION

20       These  functions may be used to obtain explanations for errors returned
21       by the utime(2) system call.
22
23   explain_utime
24       const char *explain_utime(const char *pathname,  const  struct  utimbuf
25       *times);
26
27       The explain_utime function is used to obtain an explanation of an error
28       returned by the utime(2) system call.  The least the message will  con‐
29       tain  is the value of strerror(errno), but usually it will do much bet‐
30       ter, 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       This  function  is intended to be used in a fashion similar to the fol‐
36       lowing example:
37              if (utime(pathname, times) < 0)
38              {
39                  fprintf(stderr, "%s\n", explain_utime(pathname, times));
40                  exit(EXIT_FAILURE);
41              }
42
43       pathname
44               The original pathname, exactly as passed to the utime(2) system
45               call.
46
47       times   The  original  times,  exactly as passed to the utime(2) system
48               call.
49
50       Returns:
51               The message explaining  the  error.   This  message  buffer  is
52               shared by all libexplain functions which do not supply a buffer
53               in their argument list.  This will be overwritten by  the  next
54               call  to  any  libexplain  function  which  shares this buffer,
55               including other threads.
56
57       Note: This function is not thread safe, because it shares a return buf‐
58       fer across all threads, and many other functions in this library.
59
60   explain_errno_utime
61       const char *explain_errno_utime(int errnum, const char *pathname, const
62       struct utimbuf *times);
63
64       The explain_errno_utime function is used to obtain an explanation of an
65       error returned by the utime(2) system call.  The least the message will
66       contain is the value of strerror(errnum), but usually it will  do  much
67       better, and indicate the underlying cause in more detail.
68
69       This  function  is intended to be used in a fashion similar to the fol‐
70       lowing example:
71              if (utime(pathname, times) < 0)
72              {
73                  int err = errno;
74                  fprintf(stderr, "%s\n", explain_errno_utime(err, pathname, times));
75                  exit(EXIT_FAILURE);
76              }
77
78       errnum  The error value to be decoded, usually obtained from the  errno
79               global  variable  just before this function is called.  This is
80               necessary if you need to call any code between the system  call
81               to  be explained and this function, because many libc functions
82               will alter the value of errno.
83
84       pathname
85               The original pathname, exactly as passed to the utime(2) system
86               call.
87
88       times   The  original  times,  exactly as passed to the utime(2) system
89               call.
90
91       Returns:
92               The message explaining  the  error.   This  message  buffer  is
93               shared by all libexplain functions which do not supply a buffer
94               in their argument list.  This will be overwritten by  the  next
95               call  to  any  libexplain  function  which  shares this buffer,
96               including other threads.
97
98       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
101   explain_message_utime
102       void  explain_message_utime(char *message, int message_size, const char
103       *pathname, const struct utimbuf *times);
104
105       The explain_message_utime function may be used to  obtain  an  explana‐
106       tion  of  an error returned by the utime(2) system call.  The least the
107       message will contain is the value of strerror(errno),  but  usually  it
108       will do much better, and indicate the underlying cause in more detail.
109
110       The  errno global variable will be used to obtain the error value to be
111       decoded.
112
113       This function is intended to be used in a fashion similar to  the  fol‐
114       lowing example:
115              if (utime(pathname, times) < 0)
116              {
117                  char message[3000];
118                  explain_message_utime(message, sizeof(message), pathname, times);
119                  fprintf(stderr, "%s\n", message);
120                  exit(EXIT_FAILURE);
121              }
122
123       message The  location  in  which  to  store the returned message.  If a
124               suitable message return buffer is supplied,  this  function  is
125               thread safe.
126
127       message_size
128               The  size  in  bytes  of  the  location  in  which to store the
129               returned message.
130
131       pathname
132               The original pathname, exactly as passed to the utime(2) system
133               call.
134
135       times   The  original  times,  exactly as passed to the utime(2) system
136               call.
137
138   explain_message_errno_utime
139       void explain_message_errno_utime(char *message, int  message_size,  int
140       errnum, const char *pathname, const struct utimbuf *times);
141
142       The  explain_message_errno_utime  function  may  be  used  to obtain an
143       explanation of an error returned by  the  utime(2)  system  call.   The
144       least  the  message  will contain is the value of strerror(errnum), but
145       usually it will do much better, and indicate the  underlying  cause  in
146       more detail.
147
148       This  function  is intended to be used in a fashion similar to the fol‐
149       lowing example:
150              if (utime(pathname, times) < 0)
151              {
152                  int err = errno;
153                  char message[3000];
154                  explain_message_errno_utime(message, sizeof(message), err,
155                      pathname, times);
156                  fprintf(stderr, "%s\n", message);
157                  exit(EXIT_FAILURE);
158              }
159
160       message The location in which to store  the  returned  message.   If  a
161               suitable  message  return  buffer is supplied, this function is
162               thread safe.
163
164       message_size
165               The size in bytes  of  the  location  in  which  to  store  the
166               returned message.
167
168       errnum  The  error value to be decoded, usually obtained from the errno
169               global variable just before this function is called.   This  is
170               necessary  if you need to call any code between the system call
171               to be explained and this function, because many libc  functions
172               will alter the value of errno.
173
174       pathname
175               The original pathname, exactly as passed to the utime(2) system
176               call.
177
178       times   The original times, exactly as passed to  the  utime(2)  system
179               call.
180

SEE ALSO

182       utime(2)
183               change file last access and modification times
184
185       explain_utime_or_die(3)
186               change  file  last  access  and  modification  times and report
187               errors
188
190       libexplain version 0.40
191       Copyright (C) 2008 Peter Miller
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193
194
195                                                              explain_utime(3)
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