libexplain/statfs.h File Reference

explain statfs(2) errors More...

#include <libexplain/gcc_attributes.h>

Go to the source code of this file.

Functions
void	explain_statfs_or_die (const char *pathname, struct statfs *data)
int	explain_statfs_on_error (const char *pathname, struct statfs *data) LIBEXPLAIN_WARN_UNUSED_RESULT
const char *	explain_statfs (const char *pathname, struct statfs *data) LIBEXPLAIN_WARN_UNUSED_RESULT
const char *	explain_errno_statfs (int errnum, const char *pathname, struct statfs *data) LIBEXPLAIN_WARN_UNUSED_RESULT
void	explain_message_statfs (char *message, int message_size, const char *pathname, struct statfs *data)
void	explain_message_errno_statfs (char *message, int message_size, int errnum, const char *pathname, struct statfs *data)

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Detailed Description

explain statfs(2) errors

These functions may be used to obtain explanations for errors returned by the statfs(2) system call.

Definition in file statfs.h.

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Function Documentation

const char* explain_errno_statfs	(	int	errnum,
		const char *	pathname,
		struct statfs *	data
	)

The explain_errno_statfs function is used to obtain an explanation of an error returned by the statfs(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.

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.
pathname	The original pathname, exactly as passed to the statfs(2) system call.
data	The original data, exactly as passed to the statfs(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.

Example:

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

 if (statfs(pathname, data) < 0)
 {
     int err = errno;
     fprintf(stderr, "%s\n", explain_errno_statfs(err, pathname, data));
     exit(EXIT_FAILURE);
 }

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

Note:

The statfs system call is obsolete, it would be better to use the statvfs system call instead.

void explain_message_errno_statfs	(	char *	message,
		int	message_size,
		int	errnum,
		const char *	pathname,
		struct statfs *	data
	)

The explain_message_errno_statfs function is used to obtain an explanation of an error returned by the statfs(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.

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.
pathname	The original pathname, exactly as passed to the statfs(2) system call.
data	The original data, exactly as passed to the statfs(2) system call.

Example:

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

 if (statfs(pathname, data) < 0)
 {
     int err = errno;
     char message[3000];
     explain_message_errno_statfs(message, sizeof(message), err, pathname,
         data);
     fprintf(stderr, "%s\n", message);
     exit(EXIT_FAILURE);
 }

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

Note:

The statfs system call is obsolete, it would be better to use the statvfs system call instead.

void explain_message_statfs	(	char *	message,
		int	message_size,
		const char *	pathname,
		struct statfs *	data
	)

The explain_message_statfs function is used to obtain an explanation of an error returned by the statfs(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.

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.
pathname	The original pathname, exactly as passed to the statfs(2) system call.
data	The original data, exactly as passed to the statfs(2) system call.

Example:

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

 if (statfs(pathname, data) < 0)
 {
     char message[3000];
     explain_message_statfs(message, sizeof(message), pathname, data);
     fprintf(stderr, "%s\n", message);
     exit(EXIT_FAILURE);
 }

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

Note:

The statfs system call is obsolete, it would be better to use the statvfs system call instead.

const char* explain_statfs	(	const char *	pathname,
		struct statfs *	data
	)

The explain_statfs function is used to obtain an explanation of an error returned by the statfs(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.

Parameters:

pathname	The original pathname, exactly as passed to the statfs(2) system call.
data	The original data, exactly as passed to the statfs(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.

Example:

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

 if (statfs(pathname, data) < 0)
 {
     fprintf(stderr, "%s\n", explain_statfs(pathname, data));
     exit(EXIT_FAILURE);
 }

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

Note:

The statfs system call is obsolete, it would be better to use the statvfs system call instead.

int explain_statfs_on_error	(	const char *	pathname,
		struct statfs *	data
	)

The explain_statfs_on_error function is used to call the statfs(2) system call. On failure an explanation will be printed to stderr, obtained from the explain_statfs(3) function.

Parameters:

pathname	The pathname, exactly as to be passed to the statfs(2) system call.
data	The data, exactly as to be passed to the statfs(2) system call.

Returns:

The value returned by the wrapped statfs(2) system call.

Example:

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

 if (explain_statfs_on_error(pathname, data) < 0)
 {
     ...cope with error
     ...no need to print error message
 }

Note:

The statfs system call is obsolete, it would be better to use the statvfs system call instead, possibly via the explain_statvfs_on_error function.

void explain_statfs_or_die	(	const char *	pathname,
		struct statfs *	data
	)

The explain_statfs_or_die function is used to call the statfs(2) system call. On failure an explanation will be printed to stderr, obtained from the explain_statfs(3) function, and then the process terminates by calling exit(EXIT_FAILURE).

Parameters:

pathname	The pathname, exactly as to be passed to the statfs(2) system call.
data	The data, exactly as to be passed to the statfs(2) system call.

Returns:

This function only returns on success, see statfs(2) for more information. On failure, prints an explanation and exits, it does not return.

Example:

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

 explain_statfs_or_die(pathname, data);

Note:

The statfs system call is obsolete, it would be better to use the statvfs system call instead, possibly via the explain_statvfs_or_die function.