explain_acl_from_text - explain
acl_from_text(3) errors
#include <libexplain/acl_from_text.h>
const char *explain_acl_from_text(const char *text);
const char *explain_errno_acl_from_text(int errnum, const char *text);
void explain_message_acl_from_text(char *message, int message_size, const char
*text);
void explain_message_errno_acl_from_text(char *message, int message_size, int
errnum, const char *text);
These functions may be used to obtain explanations for errors returned by the
acl_from_text(3) system call.
const char *explain_acl_from_text(const char *text);
The
explain_acl_from_text function is used to obtain an explanation of an
error returned by the
acl_from_text(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.
- text
- The original text, exactly as passed to the acl_from_text(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:
acl_t result = acl_from_text(text);
if (result < 0)
{
fprintf(stderr, "%s\n", explain_acl_from_text(text));
exit(EXIT_FAILURE);
}
The above code example is available pre-packaged as the
explain_acl_from_text_or_die(3) function.
const char *explain_errno_acl_from_text(int errnum, const char *text);
The
explain_errno_acl_from_text function is used to obtain an explanation
of an error returned by the
acl_from_text(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.
- text
- The original text, exactly as passed to the acl_from_text(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:
acl_t result = acl_from_text(text);
if (result < 0)
{
int err = errno;
fprintf(stderr, "%s\n", explain_errno_acl_from_text(err, text));
exit(EXIT_FAILURE);
}
The above code example is available pre-packaged as the
explain_acl_from_text_or_die(3) function.
void explain_message_acl_from_text(char *message, int message_size, const char
*text);
The
explain_message_acl_from_text function is used to obtain an
explanation of an error returned by the
acl_from_text(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.
- text
- The original text, exactly as passed to the acl_from_text(3) system
call.
Example: This function is intended to be used in a fashion similar to the
following example:
acl_t result = acl_from_text(text);
if (result < 0)
{
char message[3000];
explain_message_acl_from_text(message, sizeof(message), text);
fprintf(stderr, "%s\n", message);
exit(EXIT_FAILURE);
}
The above code example is available pre-packaged as the
explain_acl_from_text_or_die(3) function.
void explain_message_errno_acl_from_text(char *message, int message_size, int
errnum, const char *text);
The
explain_message_errno_acl_from_text function is used to obtain an
explanation of an error returned by the
acl_from_text(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.
- text
- The original text, exactly as passed to the acl_from_text(3) system
call.
Example: This function is intended to be used in a fashion similar to the
following example:
acl_t result = acl_from_text(text);
if (result < 0)
{
int err = errno;
char message[3000];
explain_message_errno_acl_from_text(message, sizeof(message), err, text);
fprintf(stderr, "%s\n", message);
exit(EXIT_FAILURE);
}
The above code example is available pre-packaged as the
explain_acl_from_text_or_die(3) function.
- acl_from_text(3)
- create an ACL from text
- explain_acl_from_text_or_die(3)
- create an ACL from text and report errors
libexplain version 1.3
Copyright (C) 2013 Peter Miller