libexplain/gethostid.c File Reference

#include <libexplain/ac/errno.h>
#include <libexplain/ac/unistd.h>
#include <libexplain/buffer/errno/gethostid.h>
#include <libexplain/common_message_buffer.h>
#include <libexplain/gethostid.h>

Go to the source code of this file.

Functions
const char *	explain_gethostid (void)
const char *	explain_errno_gethostid (int errnum)
void	explain_message_gethostid (char *message, int message_size)
void	explain_message_errno_gethostid (char *message, int message_size, int errnum)

---

Function Documentation

const char* explain_errno_gethostid

(

int

errnum

)

The explain_errno_gethostid function is used to obtain an explanation of an error returned by the gethostid(3) 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.

Parameters:

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.

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:

 errno = 0;
 long result = gethostid();
 if (result < 0 || errno != 0)
 {
     int err = errno;
     explain_output_error_and_die("%s", explain_errno_gethostid(err, ));
 }

The above code example is available pre-packaged as the explain_gethostid_or_die function.

Definition at line 35 of file gethostid.c.

const char* explain_gethostid

(

void

)

The explain_gethostid function is used to obtain an explanation of an error returned by the gethostid(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.

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:

 errno = 0;
 long result = gethostid();
 if (result < 0 || errno != 0)
 {
     explain_output_error_and_die("%s\n", explain_gethostid());
 }

The above code example is available pre\-packaged as the explain_gethostid_or_die function.

Definition at line 28 of file gethostid.c.

void explain_message_errno_gethostid	(	char *	message,
		int	message_size,
		int	errnum
	)

The explain_message_errno_gethostid function is used to obtain an explanation of an error returned by the gethostid(3) 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.

Parameters:

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.

Example:

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

 errno = 0;
 long result = gethostid();
 if (result < 0 || errno != 0)
 {
     int err = errno;
     char message[3000];
     explain_message_errno_gethostid(message, sizeof(message), err, );
     explain_output_error_and_die("%s", message);
 }

The above code example is available pre-packaged as the explain_gethostid_or_die function.

Definition at line 51 of file gethostid.c.

void explain_message_gethostid	(	char *	message,
		int	message_size
	)

The explain_message_gethostid function is used to obtain an explanation of an error returned by the gethostid(3) 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.

The errno global variable will be used to obtain the error value to be decoded.

Parameters:

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.

Example:

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

 errno = 0;
 long result = gethostid();
 if (result < 0 || errno != 0)
 {
     char message[3000];
     explain_message_gethostid(message, sizeof(message), );
     explain_output_error_and_die("%s", message);  * }

The above code example is available pre-packaged as the explain_gethostid_or_die function.

Definition at line 44 of file gethostid.c.