explain_usleep man page

explain_usleep — explain usleep(3) errors

Synopsis

#include <libexplain/usleep.h>

const char *explain_usleep(long long usec);
const char *explain_errno_usleep(int errnum, long long usec);
void explain_message_usleep(char *message, int message_size, long long usec);
void explain_message_errno_usleep(char *message, int message_size, int errnum, long long usec);

Description

These functions may be used to obtain explanations for errors returned by the usleep(3) system call.

explain_usleep

const char *explain_usleep(long long usec);

The explain_usleep function is used to obtain an explanation of an error returned by the usleep(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.

usec
The original usec, exactly as passed to the usleep(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:

if (usleep(usec) < 0)

{

fprintf(stderr, "%s\n", explain_usleep(usec));

    exit(EXIT_FAILURE);
}

The above code example is available pre-packaged as the explain_usleep_or_die(3) function.

explain_errno_usleep

const char *explain_errno_usleep(int errnum, long long usec);

The explain_errno_usleep function is used to obtain an explanation of an error returned by the usleep(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.
usec
The original usec, exactly as passed to the usleep(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:

if (usleep(usec) < 0)

{
    int err = errno;

fprintf(stderr, "%s\n", explain_errno_usleep(err, usec));

    exit(EXIT_FAILURE);
}

The above code example is available pre-packaged as the explain_usleep_or_die(3) function.

explain_message_usleep

void explain_message_usleep(char *message, int message_size, long long usec);

The explain_message_usleep function is used to obtain an explanation of an error returned by the usleep(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.
usec
The original usec, exactly as passed to the usleep(3) system call.

Example: This function is intended to be used in a fashion similar to the following example:

if (usleep(usec) < 0)

{
    char message[3000];

explain_message_usleep(message, sizeof(message), usec);

    fprintf(stderr, "%s\n", message);
    exit(EXIT_FAILURE);
}

The above code example is available pre-packaged as the explain_usleep_or_die(3) function.

explain_message_errno_usleep

void explain_message_errno_usleep(char *message, int message_size, int errnum, long long usec);

The explain_message_errno_usleep function is used to obtain an explanation of an error returned by the usleep(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.
usec
The original usec, exactly as passed to the usleep(3) system call.

Example: This function is intended to be used in a fashion similar to the following example:

if (usleep(usec) < 0)

{
    int err = errno;
    char message[3000];

explain_message_errno_usleep(message, sizeof(message), err, usec);

    fprintf(stderr, "%s\n", message);
    exit(EXIT_FAILURE);
}

The above code example is available pre-packaged as the explain_usleep_or_die(3) function.

See Also

usleep(3)
suspend execution for microsecond intervals
explain_usleep_or_die(3)
suspend execution for microsecond intervals and report errors

Referenced By

explain(3), explain_usleep_or_die(3).