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explain_getchar

explain_getchar

Section: C Library Functions (3)
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NAME

explain_getchar - explain getchar(3) errors  

SYNOPSIS

#include <libexplain/getchar.h>

const char *explain_getchar(void);
const char *explain_errno_getchar(int errnum, void);
void explain_message_getchar(char *message, int message_size);
void explain_message_errno_getchar(char *message, int message_size, int errnum);  

DESCRIPTION

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

explain_getchar

const char *explain_getchar(void);

The explain_getchar function is used to obtain an explanation of an error returned by the getchar(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:

int c = getchar();
if (c == EOF && ferror(stdin))
{
    fprintf(stderr, "%s\n", explain_getchar());
    exit(EXIT_FAILURE);
}
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.  

explain_errno_getchar

const char *explain_errno_getchar(int errnum);

The explain_errno_getchar function is used to obtain an explanation of an error returned by the getchar(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:

int c = getchar();
if (c == EOF && ferror(stdin))
{
    int err = errno;
    fprintf(stderr, "%s\n", explain_errno_getchar(err, ));
    exit(EXIT_FAILURE);
}
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.  

explain_message_getchar

void explain_message_getchar(char *message, int message_size);

The explain_message_getchar function may be used to obtain an explanation of an error returned by the getchar(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:

int c = getchar();
if (c == EOF && ferror(stdin))
{
    char message[3000];
    explain_message_getchar(message, sizeof(message), );
    fprintf(stderr, "%s\n", message);
    exit(EXIT_FAILURE);
}
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.
 

explain_message_errno_getchar

void explain_message_errno_getchar(char *message, int message_size, int errnum);

The explain_message_errno_getchar function may be used to obtain an explanation of an error returned by the getchar(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:

int c = getchar();
if (c == EOF && ferror(stdin))
{
    int err = errno;
    char message[3000];
    explain_message_errno_getchar(message, sizeof(message), err, );
    fprintf(stderr, "%s\n", message);
    exit(EXIT_FAILURE);
}
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.
 

SEE ALSO

getchar(3)
input of characters
explain_getchar_or_die(3)
input of characters and report errors
 

COPYRIGHT

libexplain version 0.37
Copyright (C) 2008 Peter Miller


 

Index

NAME
SYNOPSIS
DESCRIPTION
explain_getchar
explain_errno_getchar
explain_message_getchar
explain_message_errno_getchar
SEE ALSO
COPYRIGHT

This document was created by man2html, using the manual pages.
Time: 21:45:49 GMT, April 16, 2011