explain_close(3)
NAME
explain_close - explain close(2) errors
SYNOPSIS
#include <libexplain/close.h> const char *explain_close(int fildes); const char *explain_errno_close(int errnum, int fildes); void explain_message_close(char *message, int message_size, int fildes); void explain_message_errno_close(char *message, int message_size, int errnum, int fildes);
DESCRIPTION
- These functions may be used to obtain explanations for errors returned
by the close(2) system call.
- explain_close
- const char *explain_close(int fildes);
- The explain_close function is used to obtain an explanation of an error returned by the close(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.
- This function is intended to be used in a fashion similar to the following example:
if (close(fildes) < 0)
{fprintf(stderr, "%s\n", explain_close(fildes));
exit(EXIT_FAILURE);} - fildes The original fildes, exactly as passed to the close(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.
- explain_errno_close
- const char *explain_errno_close(int errnum, int fildes);
- The explain_errno_close function is used to obtain an explanation of an error returned by the close(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.
- This function is intended to be used in a fashion similar to the following example:
if (close(fildes) < 0)
{int err = errno;
fprintf(stderr, "%s\n", explain_close(err, fildes));
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.
- fildes The original fildes, exactly as passed to the close(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.
- explain_message_close
- void explain_message_close(char *message, int message_size, int fildes);
- The explain_message_close function is used to obtain an explanation of an error returned by the close(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.
- This function is intended to be used in a fashion similar to the following example:
if (close(fildes) < 0)
{char message[3000];
explain_message_close(message, sizeof(message), fildes);
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.
- fildes The original fildes, exactly as passed to the close(2) system
- call.
- explain_message_errno_close
- void explain_message_errno_close(char *message, int message_size, int errnum, int fildes);
- The explain_message_errno_close function is used to obtain an explanation of an error returned by the close(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.
- This function is intended to be used in a fashion similar to the following example:
if (close(fildes) < 0)
{int err = errno;
char message[3000];
explain_message_errno_close(message, sizeof(message), err, fildes);
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.
- fildes The original fildes, exactly as passed to the close(2) system
- call.
SEE ALSO
close close a file descriptor
- explain_close_or_die
- close a file descriptor and report errors
COPYRIGHT
- libexplain version 0.37
Copyright (C) 2008 Peter Miller