#include <libexplain/ac/errno.h>
#include <libexplain/ac/stdio.h>
#include <libexplain/buffer/errno/ferror.h>
#include <libexplain/common_message_buffer.h>
#include <libexplain/ferror.h>

Functions
const char *	explain_ferror (FILE *fp)
const char *	explain_errno_ferror (int errnum, FILE *fp)
void	explain_message_ferror (char message, int message_size, FILE fp)
void	explain_message_errno_ferror (char message, int message_size, int errnum, FILE fp)

Function Documentation

const char* explain_errno_ferror	(	int	errnum,
		FILE *	fp
	)

The explain_errno_ferror function is used to obtain an explanation of an error returned by the ferror(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.

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

 if (ferror(fp) < 0)
 {
     int err = errno;
     fprintf(stderr, "%s\n", explain_errno_ferror(err, fp));
     exit(EXIT_FAILURE);
 }

It is essential that this function cal be placed as close as possible to the I/O code that has caused the problem, otherwise intervening code could have altered the errno global variable.

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

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.
fp	The original fp, exactly as passed to the ferror(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.

Definition at line 35 of file ferror.c.

const char* explain_ferror ( FILE * fp )

The explain_ferror function is used to obtain an explanation of an error returned by the ferror(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.

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

 if (ferror(fp) < 0)
 {
     fprintf(stderr, "%s\n", explain_ferror(fp));
     exit(EXIT_FAILURE);
 }

It is essential that this function cal be placed as close as possible to the I/O code that has caused the problem, otherwise intervening code could have altered the errno global variable.

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

Parameters:

fp	The original fp, exactly as passed to the ferror(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.

Definition at line 28 of file ferror.c.

void explain_message_errno_ferror	(	char *	message,
		int	message_size,
		int	errnum,
		FILE *	fp
	)

The explain_message_errno_ferror function is used to obtain an explanation of an error returned by the ferror(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.

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

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

It is essential that this function cal be placed as close as possible to the I/O code that has caused the problem, otherwise intervening code could have altered the errno global variable.

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

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.
fp	The original fp, exactly as passed to the ferror(3) system call.

Definition at line 62 of file ferror.c.

void explain_message_ferror	(	char *	message,
		int	message_size,
		FILE *	fp
	)

The explain_message_ferror function is used to obtain an explanation of an error returned by the ferror(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.

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

 if (ferror(fp) < 0)
 {
     char message[3000];
     explain_message_ferror(message, sizeof(message), fp);
     fprintf(stderr, "%s\n", message);
     exit(EXIT_FAILURE);
 }

It is essential that this function cal be placed as close as possible to the I/O code that has caused the problem, otherwise intervening code could have altered the errno global variable.

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

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.
fp	The original fp, exactly as passed to the ferror(3) system call.

Definition at line 49 of file ferror.c.

Functions

Function Documentation