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

6       explain_tcflush - explain tcflush(3) errors
7

SYNOPSIS

9       #include <libexplain/tcflush.h>
10       const char *explain_tcflush(int fildes, int selector);
11       const char *explain_errno_tcflush(int errnum, int fildes, int selec‐
12       tor);
13       void explain_message_tcflush(char *message, int message_size, int
14       fildes, int selector);
15       void explain_message_errno_tcflush(char *message, int message_size, int
16       errnum, int fildes, int selector);
17

DESCRIPTION

19       These functions may be used to obtain explanations for errors  returned
20       by the tcflush(3) system call.
21
22   explain_tcflush
23       const char *explain_tcflush(int fildes, int selector);
24
25       The  explain_tcflush  function  is  used to obtain an explanation of an
26       error returned by the tcflush(3) 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       fildes  The original fildes, exactly as passed to the tcflush(3) system
34               call.
35
36       selector
37               The original selector, exactly as passed to the tcflush(3) sys‐
38               tem call.
39
40       Returns:
41               The message explaining the error. This message buffer is shared
42               by all libexplain functions which do not  supply  a  buffer  in
43               their argument list.  This will be overwritten by the next call
44               to any libexplain function which shares this buffer,  including
45               other threads.
46
47       Note: This function is not thread safe, because it shares a return buf‐
48       fer across all threads, and many other functions in this library.
49
50       Example: This function is intended to be used in a fashion  similar  to
51       the following example:
52              if (tcflush(fildes, selector) < 0)
53              {
54                  fprintf(stderr, "%s\n", explain_tcflush(fildes, selector));
55                  exit(EXIT_FAILURE);
56              }
57
58       The   above   code   example   is   available   pre‐packaged   as   the
59       explain_tcflush_or_die(3) function.
60
61   explain_errno_tcflush
62       const char *explain_errno_tcflush(int errnum, int fildes, int selec‐
63       tor);
64
65       The  explain_errno_tcflush function is used to obtain an explanation of
66       an error returned by the tcflush(3) system call. The least the  message
67       will  contain  is  the value of strerror(errno), but usually it will do
68       much better, and indicate the underlying cause in more detail.
69
70       errnum  The error value to be decoded, usually obtained from the  errno
71               global  variable  just  before this function is called. This is
72               necessary if you need to call any code between the system  call
73               to  be explained and this function, because many libc functions
74               will alter the value of errno.
75
76       fildes  The original fildes, exactly as passed to the tcflush(3) system
77               call.
78
79       selector
80               The original selector, exactly as passed to the tcflush(3) sys‐
81               tem call.
82
83       Returns:
84               The message explaining the error. This message buffer is shared
85               by  all  libexplain  functions  which do not supply a buffer in
86               their argument list.  This will be overwritten by the next call
87               to  any libexplain function which shares this buffer, including
88               other threads.
89
90       Note: This function is not thread safe, because it shares a return buf‐
91       fer across all threads, and many other functions in this library.
92
93       Example:  This  function is intended to be used in a fashion similar to
94       the following example:
95              if (tcflush(fildes, selector) < 0)
96              {
97                  int err = errno;
98                  fprintf(stderr, "%s\n", explain_errno_tcflush(err, fildes,
99                  selector));
100                  exit(EXIT_FAILURE);
101              }
102
103       The   above   code   example   is   available   pre‐packaged   as   the
104       explain_tcflush_or_die(3) function.
105
106   explain_message_tcflush
107       void explain_message_tcflush(char *message, int message_size, int
108       fildes, int selector);
109
110       The  explain_message_tcflush  function is used to obtain an explanation
111       of an error returned by the tcflush(3) system call. The least the  mes‐
112       sage  will contain is the value of strerror(errno), but usually it will
113       do much better, and indicate the underlying cause in more detail.
114
115       The errno global variable will be used to obtain the error value to  be
116       decoded.
117
118       message The location in which to store the returned message. If a suit‐
119               able message return buffer is supplied, this function is thread
120               safe.
121
122       message_size
123               The  size  in  bytes  of  the  location  in  which to store the
124               returned message.
125
126       fildes  The original fildes, exactly as passed to the tcflush(3) system
127               call.
128
129       selector
130               The original selector, exactly as passed to the tcflush(3) sys‐
131               tem call.
132
133       Example: This function is intended to be used in a fashion  similar  to
134       the following example:
135              if (tcflush(fildes, selector) < 0)
136              {
137                  char message[3000];
138                  explain_message_tcflush(message, sizeof(message), fildes,
139                  selector);
140                  fprintf(stderr, "%s\n", message);
141                  exit(EXIT_FAILURE);
142              }
143
144       The   above   code   example   is   available   pre‐packaged   as   the
145       explain_tcflush_or_die(3) function.
146
147   explain_message_errno_tcflush
148       void explain_message_errno_tcflush(char *message, int message_size, int
149       errnum, int fildes, int selector);
150
151       The explain_message_errno_tcflush function is used to obtain an  expla‐
152       nation  of  an  error returned by the tcflush(3) system call. The least
153       the message will contain is the value of strerror(errno),  but  usually
154       it  will  do  much  better,  and  indicate the underlying cause in more
155       detail.
156
157       message The location in which to store the returned message. If a suit‐
158               able message return buffer is supplied, this function is thread
159               safe.
160
161       message_size
162               The size in bytes  of  the  location  in  which  to  store  the
163               returned message.
164
165       errnum  The  error value to be decoded, usually obtained from the errno
166               global variable just before this function is  called.  This  is
167               necessary  if you need to call any code between the system call
168               to be explained and this function, because many libc  functions
169               will alter the value of errno.
170
171       fildes  The original fildes, exactly as passed to the tcflush(3) system
172               call.
173
174       selector
175               The original selector, exactly as passed to the tcflush(3) sys‐
176               tem call.
177
178       Example:  This  function is intended to be used in a fashion similar to
179       the following example:
180              if (tcflush(fildes, selector) < 0)
181              {
182                  int err = errno;
183                  char message[3000];
184                  explain_message_errno_tcflush(message, sizeof(message), err,
185                  fildes, selector);
186                  fprintf(stderr, "%s\n", message);
187                  exit(EXIT_FAILURE);
188              }
189
190       The   above   code   example   is   available   pre‐packaged   as   the
191       explain_tcflush_or_die(3) function.
192

SEE ALSO

194       tcflush(3)
195               discard terminal data
196
197       explain_tcflush_or_die(3)
198               discard terminal data and report errors
199
201       libexplain version 1.4
202       Copyright (C) 2009 Peter Miller
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206                                                            explain_tcflush(3)
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