explain_acl_set_file(3)

NAME
explain_acl_set_file - explain acl_set_file(3) errors

SYNOPSIS
#include <libexplain/acl_set_file.h>

const char *explain_acl_set_file(const char *pathname, acl_type_t type, acl_t acl);
const char *explain_errno_acl_set_file(int errnum, const char *pathname, acl_type_t type, acl_t acl);
void explain_message_acl_set_file(char *message, int message_size, const char *pathname, acl_type_t type, acl_t acl);
void explain_message_errno_acl_set_file(char *message, int message_size, int errnum, const char *pathname, acl_type_t type, acl_t acl);

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

  explain_acl_set_file
const char *explain_acl_set_file(const char *pathname, acl_type_t type, acl_t acl);

The explain_acl_set_file function is used to obtain an explanation of an error returned by the acl_set_file(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.

pathname
    The original pathname, exactly as passed to the acl_set_file(3) system call.

type
    The original type, exactly as passed to the acl_set_file(3) system call.

acl The original acl, exactly as passed to the acl_set_file(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_file(pathname, type, acl) < 0)
    {
    fprintf(stderr, "%s\n", explain_acl_set_file(pathname, type, acl));
        exit(EXIT_FAILURE);
    }

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

  explain_errno_acl_set_file
const char *explain_errno_acl_set_file(int errnum, const char *pathname, acl_type_t type, acl_t acl);

The explain_errno_acl_set_file function is used to obtain an explanation of an error returned by the acl_set_file(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.

pathname
    The original pathname, exactly as passed to the acl_set_file(3) system call.

type
    The original type, exactly as passed to the acl_set_file(3) system call.

acl The original acl, exactly as passed to the acl_set_file(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_file(pathname, type, acl) < 0)
    {
        int err = errno;
    fprintf(stderr, "%s\n", explain_errno_acl_set_file(err, pathname, type, acl));
        exit(EXIT_FAILURE);
    }

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

  explain_message_acl_set_file
void explain_message_acl_set_file(char *message, int message_size, const char *pathname, acl_type_t type, acl_t acl);

The explain_message_acl_set_file function is used to obtain an explanation of an error returned by the acl_set_file(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.

pathname
    The original pathname, exactly as passed to the acl_set_file(3) system call.

type
    The original type, exactly as passed to the acl_set_file(3) system call.

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

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

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

  explain_message_errno_acl_set_file
void explain_message_errno_acl_set_file(char *message, int message_size, int errnum, const char *pathname, acl_type_t type, acl_t acl);

The explain_message_errno_acl_set_file function is used to obtain an explanation of an error returned by the acl_set_file(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.

pathname
    The original pathname, exactly as passed to the acl_set_file(3) system call.

type
    The original type, exactly as passed to the acl_set_file(3) system call.

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

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

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

SEE ALSO

acl_set_file(3)
    set an ACL by filename

explain_acl_set_file_or_die(3)
    set an ACL by filename and report errors

COPYRIGHT
libexplain version
Copyright (C) 2013 Peter Miller