explain_acl_set_fd(3)

NAME
explain_acl_set_fd - explain acl_set_fd(3) errors

SYNOPSIS
#include <libexplain/acl_set_fd.h>

const char *explain_acl_set_fd(int fildes, acl_t acl);
const char *explain_errno_acl_set_fd(int errnum, int fildes, acl_t acl);
void explain_message_acl_set_fd(char *message, int message_size, int fildes, acl_t acl);
void explain_message_errno_acl_set_fd(char *message, int message_size, int errnum, int fildes, acl_t acl);

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

  explain_acl_set_fd
const char *explain_acl_set_fd(int fildes, acl_t acl);

The explain_acl_set_fd function is used to obtain an explanation of an error returned by the acl_set_fd(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.

fildes
    The original fildes, exactly as passed to the acl_set_fd(3) system call.

acl The original acl, exactly as passed to the acl_set_fd(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.

Example: This function is intended to be used in a fashion similar to the following example:
    if (acl_set_fd(fildes, acl) < 0)
    {
    fprintf(stderr, "%s\n", explain_acl_set_fd(fildes, acl));
        exit(EXIT_FAILURE);
    }

The above code example is available pre-packaged as the explain_acl_set_fd_or_die(3) function.

  explain_errno_acl_set_fd
const char *explain_errno_acl_set_fd(int errnum, int fildes, acl_t acl);

The explain_errno_acl_set_fd function is used to obtain an explanation of an error returned by the acl_set_fd(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.

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 acl_set_fd(3) system call.

acl The original acl, exactly as passed to the acl_set_fd(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.

Example: This function is intended to be used in a fashion similar to the following example:
    if (acl_set_fd(fildes, acl) < 0)
    {
        int err = errno;
    fprintf(stderr, "%s\n", explain_errno_acl_set_fd(err, fildes, acl));
        exit(EXIT_FAILURE);
    }

The above code example is available pre-packaged as the explain_acl_set_fd_or_die(3) function.

  explain_message_acl_set_fd
void explain_message_acl_set_fd(char *message, int message_size, int fildes, acl_t acl);

The explain_message_acl_set_fd function is used to obtain an explanation of an error returned by the acl_set_fd(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.

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 acl_set_fd(3) system call.

acl The original acl, exactly as passed to the acl_set_fd(3) system call.

Example: This function is intended to be used in a fashion similar to the following example:
    if (acl_set_fd(fildes, acl) < 0)
    {
        char message[3000];
    explain_message_acl_set_fd(message, sizeof(message), fildes, acl);
        fprintf(stderr, "%s\n", message);
        exit(EXIT_FAILURE);
    }

The above code example is available pre-packaged as the explain_acl_set_fd_or_die(3) function.

  explain_message_errno_acl_set_fd
void explain_message_errno_acl_set_fd(char *message, int message_size, int errnum, int fildes, acl_t acl);

The explain_message_errno_acl_set_fd function is used to obtain an explanation of an error returned by the acl_set_fd(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.

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 acl_set_fd(3) system call.

acl The original acl, exactly as passed to the acl_set_fd(3) system call.

Example: This function is intended to be used in a fashion similar to the following example:
    if (acl_set_fd(fildes, acl) < 0)
    {
        int err = errno;
        char message[3000];
    explain_message_errno_acl_set_fd(message, sizeof(message), err, fildes, acl);
        fprintf(stderr, "%s\n", message);
        exit(EXIT_FAILURE);
    }

The above code example is available pre-packaged as the explain_acl_set_fd_or_die(3) function.

SEE ALSO

acl_set_fd(3)
    set an ACL by file descriptor

explain_acl_set_fd_or_die(3)
    set an ACL by file descriptor and report errors

COPYRIGHT
libexplain version
Copyright (C) 2013 Peter Miller