Provided by: libexplain-dev_1.4.D001-7_amd64 
NAME
explain_wait3 - explain wait3(2) errors
SYNOPSIS
#include <libexplain/wait3.h>
const char *explain_wait3(int *status, int options, struct rusage *rusage);
const char *explain_errno_wait3(int errnum, int *status, int options, struct rusage *rusage);
void explain_message_wait3(char *message, int message_size, int *status, int options, struct rusage
*rusage);
void explain_message_errno_wait3(char *message, int message_size, int errnum, int *status, int options,
struct rusage *rusage);
DESCRIPTION
These functions may be used to obtain explanations for errors returned by the wait3(2) system call.
explain_wait3
const char *explain_wait3(int *status, int options, struct rusage *rusage);
The explain_wait3 function is used to obtain an explanation of an error returned by the wait3(2) system
call. The least the message will contain is the value of strerror(errno), but usually it will do much
better, and indicate the underlying cause in more detail.
The errno global variable will be used to obtain the error value to be decoded.
This function is intended to be used in a fashion similar to the following example:
int pid = wait3(status, options, rusage);
if (pid < 0)
{
fprintf(stderr, "%s\n", explain_wait3(status, options, rusage));
exit(EXIT_FAILURE);
}
status The original status, exactly as passed to the wait3(2) system call.
options The original options, exactly as passed to the wait3(2) system call.
rusage The original rusage, exactly as passed to the wait3(2) system call.
Returns:
The message explaining the error. This message buffer is shared by all libexplain functions
which do not supply a buffer in their argument list. This will be overwritten by the next call
to any libexplain function which shares this buffer, including other threads.
Note: This function is not thread safe, because it shares a return buffer across all threads, and many
other functions in this library.
explain_errno_wait3
const char *explain_errno_wait3(int errnum, int *status, int options, struct rusage *rusage);
The explain_errno_wait3 function is used to obtain an explanation of an error returned by the wait3(2)
system call. The least the message will contain is the value of strerror(errnum), but usually it will do
much better, and indicate the underlying cause in more detail.
This function is intended to be used in a fashion similar to the following example:
int pid = wait3(status, options, rusage);
if (pid < 0)
{
int err = errno;
fprintf(stderr, "%s\n", explain_errno_wait3(err, status, options,
rusage));
exit(EXIT_FAILURE);
}
errnum The error value to be decoded, usually obtained from the errno global variable just before this
function is called. This is necessary if you need to call any code between the system call to be
explained and this function, because many libc functions will alter the value of errno.
status The original status, exactly as passed to the wait3(2) system call.
options The original options, exactly as passed to the wait3(2) system call.
rusage The original rusage, exactly as passed to the wait3(2) system call.
Returns:
The message explaining the error. This message buffer is shared by all libexplain functions
which do not supply a buffer in their argument list. This will be overwritten by the next call
to any libexplain function which shares this buffer, including other threads.
Note: This function is not thread safe, because it shares a return buffer across all threads, and many
other functions in this library.
explain_message_wait3
void explain_message_wait3(char *message, int message_size, int *status, int options, struct rusage
*rusage);
The explain_message_wait3 function may be used to obtain an explanation of an error returned by the
wait3(2) system call. The least the message will contain is the value of strerror(errno), but usually it
will do much better, and indicate the underlying cause in more detail.
The errno global variable will be used to obtain the error value to be decoded.
This function is intended to be used in a fashion similar to the following example:
int pid = wait3(status, options, rusage);
if (pid < 0)
{
char message[3000];
explain_message_wait3(message, sizeof(message),
status, options, rusage);
fprintf(stderr, "%s\n", message);
exit(EXIT_FAILURE);
}
message The location in which to store the returned message. If a suitable message return buffer is
supplied, this function is thread safe.
message_size
The size in bytes of the location in which to store the returned message.
status The original status, exactly as passed to the wait3(2) system call.
options The original options, exactly as passed to the wait3(2) system call.
rusage The original rusage, exactly as passed to the wait3(2) system call.
explain_message_errno_wait3
void explain_message_errno_wait3(char *message, int message_size, int errnum, int *status, int options,
struct rusage *rusage);
The explain_message_errno_wait3 function may be used to obtain an explanation of an error returned by the
wait3(2) system call. The least the message will contain is the value of strerror(errnum), but usually
it will do much better, and indicate the underlying cause in more detail.
This function is intended to be used in a fashion similar to the following example:
int pid = wait3(status, options, rusage);
if (pid < 0)
{
int err = errno;
char message[3000];
explain_message_errno_wait3(message, sizeof(message), err,
status, options, rusage);
fprintf(stderr, "%s\n", message);
exit(EXIT_FAILURE);
}
message The location in which to store the returned message. If a suitable message return buffer is
supplied, this function is thread safe.
message_size
The size in bytes of the location in which to store the returned message.
errnum The error value to be decoded, usually obtained from the errno global variable just before this
function is called. This is necessary if you need to call any code between the system call to be
explained and this function, because many libc functions will alter the value of errno.
status The original status, exactly as passed to the wait3(2) system call.
options The original options, exactly as passed to the wait3(2) system call.
rusage The original rusage, exactly as passed to the wait3(2) system call.
SEE ALSO
wait3(2)
wait for process to change state
explain_wait3_or_die(3)
wait for process to change state and report errors
COPYRIGHT
libexplain version 1.4
Copyright (C) 2008 Peter Miller
explain_wait3(3)