1explain_kill(3) Library Functions Manual explain_kill(3)
2
6 explain_kill - explain kill(2) errors
7
9 #include <libexplain/kill.h>
10 const char *explain_kill(pid_t pid, int sig);
11 const char *explain_errno_kill(int errnum, pid_t pid, int sig);
12 void explain_message_kill(char *message, int message_size, pid_t pid,
13 int sig);
14 void explain_message_errno_kill(char *message, int message_size, int
15 errnum, pid_t pid, int sig);
16
18 These functions may be used to obtain explanations for errors returned
19 by the kill(2) system call.
20 explain_kill
22 const char *explain_kill(pid_t pid, int sig);
23 The explain_kill function is used to obtain an explanation of an error
25 returned by the kill(2) system call. The least the message will contain
26 is the value of strerror(errno), but usually it will do much better,
27 and indicate the underlying cause in more detail.
28 The errno global variable will be used to obtain the error value to be
30 decoded.
31 pid The original pid, exactly as passed to the kill(2) system call.
33 sig The original sig, exactly as passed to the kill(2) system call.
35 Returns:
37 The message explaining the error. This message buffer is shared
38 by all libexplain functions which do not supply a buffer in
39 their argument list. This will be overwritten by the next call
40 to any libexplain function which shares this buffer, including
41 other threads.
42 Note: This function is not thread safe, because it shares a return buf‐
44 fer across all threads, and many other functions in this library.
45 Example: This function is intended to be used in a fashion similar to
47 the following example:
48 if (kill(pid, sig) < 0)
49 {
50 fprintf(stderr, "%s\n", explain_kill(pid, sig));
51 exit(EXIT_FAILURE);
52 }
53 The above code example is available pre‐packaged as the
55 explain_kill_or_die(3) function.
56 explain_errno_kill
58 const char *explain_errno_kill(int errnum, pid_t pid, int sig);
59 The explain_errno_kill function is used to obtain an explanation of an
61 error returned by the kill(2) system call. The least the message will
62 contain is the value of strerror(errno), but usually it will do much
63 better, and indicate the underlying cause in more detail.
64 errnum The error value to be decoded, usually obtained from the errno
66 global variable just before this function is called. This is
67 necessary if you need to call any code between the system call
68 to be explained and this function, because many libc functions
69 will alter the value of errno.
70 pid The original pid, exactly as passed to the kill(2) system call.
72 sig The original sig, exactly as passed to the kill(2) system call.
74 Returns:
76 The message explaining the error. This message buffer is shared
77 by all libexplain functions which do not supply a buffer in
78 their argument list. This will be overwritten by the next call
79 to any libexplain function which shares this buffer, including
80 other threads.
81 Note: This function is not thread safe, because it shares a return buf‐
83 fer across all threads, and many other functions in this library.
84 Example: This function is intended to be used in a fashion similar to
86 the following example:
87 if (kill(pid, sig) < 0)
88 {
89 int err = errno;
90 fprintf(stderr, "%s\n", explain_errno_kill(err, pid, sig));
91 exit(EXIT_FAILURE);
92 }
93 The above code example is available pre‐packaged as the
95 explain_kill_or_die(3) function.
96 explain_message_kill
98 void explain_message_kill(char *message, int message_size, pid_t pid,
99 int sig);
100 The explain_message_kill function is used to obtain an explanation of
102 an error returned by the kill(2) system call. The least the message
103 will contain is the value of strerror(errno), but usually it will do
104 much better, and indicate the underlying cause in more detail.
105 The errno global variable will be used to obtain the error value to be
107 decoded.
108 message The location in which to store the returned message. If a suit‐
110 able message return buffer is supplied, this function is thread
111 safe.
112 message_size
114 The size in bytes of the location in which to store the
115 returned message.
116 pid The original pid, exactly as passed to the kill(2) system call.
118 sig The original sig, exactly as passed to the kill(2) system call.
120 Example: This function is intended to be used in a fashion similar to
122 the following example:
123 if (kill(pid, sig) < 0)
124 {
125 char message[3000];
126 explain_message_kill(message, sizeof(message), pid, sig);
127 fprintf(stderr, "%s\n", message);
128 exit(EXIT_FAILURE);
129 }
130 The above code example is available pre‐packaged as the
132 explain_kill_or_die(3) function.
133 explain_message_errno_kill
135 void explain_message_errno_kill(char *message, int message_size, int
136 errnum, pid_t pid, int sig);
137 The explain_message_errno_kill function is used to obtain an explana‐
139 tion of an error returned by the kill(2) system call. The least the
140 message will contain is the value of strerror(errno), but usually it
141 will do much better, and indicate the underlying cause in more detail.
142 message The location in which to store the returned message. If a suit‐
144 able message return buffer is supplied, this function is thread
145 safe.
146 message_size
148 The size in bytes of the location in which to store the
149 returned message.
150 errnum The error value to be decoded, usually obtained from the errno
152 global variable just before this function is called. This is
153 necessary if you need to call any code between the system call
154 to be explained and this function, because many libc functions
155 will alter the value of errno.
156 pid The original pid, exactly as passed to the kill(2) system call.
158 sig The original sig, exactly as passed to the kill(2) system call.
160 Example: This function is intended to be used in a fashion similar to
162 the following example:
163 if (kill(pid, sig) < 0)
164 {
165 int err = errno;
166 char message[3000];
167 explain_message_errno_kill(message, sizeof(message), err,
168 pid, sig);
169 fprintf(stderr, "%s\n", message);
170 exit(EXIT_FAILURE);
171 }
172 The above code example is available pre‐packaged as the
174 explain_kill_or_die(3) function.
175
177 kill(2) send signal to a process
178 explain_kill_or_die(3)
180 send signal to a process and report errors
181
183 libexplain version 1.4
184 Copyright (C) 2009 Peter Miller
185 explain_kill(3)