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

6       explain_symlink - explain symlink(2) errors
7

SYNOPSIS

9       #include <libexplain/symlink.h>
10       const char *explain_symlink(const char *oldpath, const char *newpath);
11       const  char  *explain_errno_symlink(int  errnum,  const  char *oldpath,
12       const char *newpath);
13       void explain_message_symlink(char  *message,  int  message_size,  const
14       char *oldpath, const char *newpath);
15       void explain_message_errno_symlink(char *message, int message_size, int
16       errnum, const char *oldpath, const char *newpath);
17

DESCRIPTION

19       These functions may be  used  to  obtain  explanations  for  symlink(2)
20       errors.
21
22   explain_symlink
23       const char *explain_symlink(const char *oldpath, const char *newpath);
24
25       The  explain_symlink  function  is  used to obtain an explanation of an
26       error returned by the symlink(2) 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
30       The errno global variable will be used to obtain the error value to  be
31       decoded.
32
33       This  function  is intended to be used in a fashion similar to the fol‐
34       lowing example:
35              if (symlink(oldpath, rewpath) < 0)
36              {
37                  fprintf(stderr, '%s0, explain_symlink(oldpath, newpath));
38                  exit(EXIT_FAILURE);
39              }
40
41       oldpath The original oldpath, exactly as passed to the symlink(2)  sys‐
42               tem call.
43
44       newpath The  original newpath, exactly as passed to the symlink(2) sys‐
45               tem call.
46
47       Returns:
48               The message explaining  the  error.   This  message  buffer  is
49               shared by all libexplain functions which do not supply a buffer
50               in their argument list.  This will be overwritten by  the  next
51               call  to  any  libexplain  function  which  shares this buffer,
52               including other threads.
53
54       Note: This function is not thread safe, because it shares a return buf‐
55       fer across all threads, and many other functions in this library.
56
57   explain_errno_symlink
58       const  char  *explain_errno_symlink(int  errnum,  const  char *oldpath,
59       const char * newpath);
60
61       The explain_errno_symlink function is used to obtain an explanation  of
62       an error returned by the symlink(2) system call.  The least the message
63       will contain is the value of strerror(errnum), but usually it  will  do
64       much better, and indicate the underlying cause in more detail.
65
66       This  function  is intended to be used in a fashion similar to the fol‐
67       lowing example:
68              if (symlink(oldpath, newpath) < 0)
69              {
70                  int err = errno;
71                  fprintf(stderr, '%s0, explain_errno_symlink(err, oldpath,
72                      newpath));
73                  exit(EXIT_FAILURE);
74              }
75
76       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
82       oldpath The original oldpath, exactly as passed to the symlink(2)  sys‐
83               tem call.
84
85       newpath The  original newpath, exactly as passed to the symlink(2) sys‐
86               tem call.
87
88       Returns:
89               The message explaining  the  error.   This  message  buffer  is
90               shared by all libexplain functions which do not supply a buffer
91               in their argument list.  This will be overwritten by  the  next
92               call  to  any  libexplain  function  which  shares this buffer,
93               including other threads.
94
95       Note: This function is not thread safe, because it shares a return buf‐
96       fer across all threads, and many other functions in this library.
97
98   explain_message_symlink
99       void  explain_message_symlink(char  *message,  int  message_size, const
100       char *oldpath, const char *newpath);
101
102       The explain_message_symlink function is used to obtain  an  explanation
103       of an error returned by the symlink(2) system call.  The least the mes‐
104       sage will contain is the value of strerror(errno), but usually it  will
105       do much better, and indicate the underlying cause in more detail.
106
107       The  errno]fP global variable will be used to obtain the error value to
108       be decoded.
109
110       This function is intended to be used in a fashion similar to  the  fol‐
111       lowing example:
112              if (symlink(oldpath, newpath) < 0)
113              {
114                  char message[3000];
115                  explain_message_symlink(message, sizeof(message), oldpath,
116                      newpath);
117                  fprintf(stderr, '%s0, message);
118                  exit(EXIT_FAILURE);
119              }
120
121       message The location in which to store the returned message.  Because a
122               message return buffer  has  been  supplied,  this  function  is
123               thread safe.
124
125       message_size
126               The  size  in  bytes  of  the  location  in  which to store the
127               returned message.
128
129       oldpath The original oldpath, exactly as passed to the symlink(2)  sys‐
130               tem call.
131
132       newpath The  original newpath, exactly as passed to the symlink(2) sys‐
133               tem call.
134
135   explain_message_errno_symlink
136       void explain_message_errno_symlink(char *message, int message_size, int
137       errnum, const char *oldpath, const char *newpath);
138
139       The  explain_message_errno_symlink function is used to obtain an expla‐
140       nation of an error returned by the symlink(2) system call.   The  least
141       the  message will contain is the value of strerror(errnum), but usually
142       it will do much better, and  indicate  the  underlying  cause  in  more
143       detail.
144
145       This  function  is intended to be used in a fashion similar to the fol‐
146       lowing example:
147
148       if (symlink(oldpath, newpath) < 0)
149       {
150           int err = errno;
151           char message[3000];
152           explain_message_errno_symlink(message, sizeof(message), err,
153               oldpath, newpath);
154           fprintf(stderr, '%s0, message);
155           exit(EXIT_FAILURE);
156       }
157
158       message The location in which to store the returned message.  Because a
159               message  return  buffer  has  been  supplied,  this function is
160               thread 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       oldpath The  original oldpath, exactly as passed to the symlink(2) sys‐
173               tem call.
174
175       newpath The original newpath, exactly as passed to the symlink(2)  sys‐
176               tem call.
177
179       libexplain version 0.40
180       Copyright (C) 2008 Peter Miller
181

AUTHOR

183       Written by Peter Miller <pmiller@opensource.org.au>
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187                                                            explain_symlink(3)
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