Provided by: libexplain-dev_1.4.D001-7_amd64 
NAME
explain_sleep - explain sleep(3) errors
SYNOPSIS
#include <libexplain/sleep.h>
const char *explain_sleep(unsigned int seconds);
const char *explain_errno_sleep(int errnum, unsigned int seconds);
void explain_message_sleep(char *message, int message_size, unsigned int seconds);
void explain_message_errno_sleep(char *message, int message_size, int errnum, unsigned int seconds);
DESCRIPTION
These functions may be used to obtain explanations for errors returned by the sleep(3) system call.
explain_sleep
const char *explain_sleep(unsigned int seconds);
The explain_sleep function is used to obtain an explanation of an error returned by the sleep(3) 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.
seconds The original seconds, exactly as passed to the sleep(3) 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.
Example: This function is intended to be used in a fashion similar to the following example:
unsigned int result = sleep(seconds);
if (result < 0)
{
fprintf(stderr, "%s\n", explain_sleep(seconds));
exit(EXIT_FAILURE);
}
The above code example is available pre-packaged as the explain_sleep_or_die(3) function.
explain_errno_sleep
const char *explain_errno_sleep(int errnum, unsigned int seconds);
The explain_errno_sleep function is used to obtain an explanation of an error returned by the sleep(3)
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.
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.
seconds The original seconds, exactly as passed to the sleep(3) 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.
Example: This function is intended to be used in a fashion similar to the following example:
unsigned int result = sleep(seconds);
if (result < 0)
{
int err = errno;
fprintf(stderr, "%s\n", explain_errno_sleep(err, seconds));
exit(EXIT_FAILURE);
}
The above code example is available pre-packaged as the explain_sleep_or_die(3) function.
explain_message_sleep
void explain_message_sleep(char *message, int message_size, unsigned int seconds);
The explain_message_sleep function is used to obtain an explanation of an error returned by the sleep(3)
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.
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.
seconds The original seconds, exactly as passed to the sleep(3) system call.
Example: This function is intended to be used in a fashion similar to the following example:
unsigned int result = sleep(seconds);
if (result < 0)
{
char message[3000];
explain_message_sleep(message, sizeof(message), seconds);
fprintf(stderr, "%s\n", message);
exit(EXIT_FAILURE);
}
The above code example is available pre-packaged as the explain_sleep_or_die(3) function.
explain_message_errno_sleep
void explain_message_errno_sleep(char *message, int message_size, int errnum, unsigned int seconds);
The explain_message_errno_sleep function is used to obtain an explanation of an error returned by the
sleep(3) 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.
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.
seconds The original seconds, exactly as passed to the sleep(3) system call.
Example: This function is intended to be used in a fashion similar to the following example:
unsigned int result = sleep(seconds);
if (result < 0)
{
int err = errno;
char message[3000];
explain_message_errno_sleep(message, sizeof(message), err, seconds);
fprintf(stderr, "%s\n", message);
exit(EXIT_FAILURE);
}
The above code example is available pre-packaged as the explain_sleep_or_die(3) function.
SEE ALSO
sleep(3)
Sleep for the specified number of seconds
explain_sleep_or_die(3)
Sleep for the specified number of seconds and report errors
COPYRIGHT
libexplain version 1.4
Copyright (C) 2013 Peter Miller
explain_sleep(3)