explain_strcoll(3) explain strcoll(3) errors

SYNOPSIS

#include <libexplain/strcoll.h>

const char *explain_strcoll(const char *s1, const char *s2);
const char *explain_errno_strcoll(int errnum, const char *s1, const char *s2);
void explain_message_strcoll(char *message, int message_size, const char *s1, const char *s2);
void explain_message_errno_strcoll(char *message, int message_size, int errnum, const char *s1, const char *s2);

DESCRIPTION

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

explain_strcoll

const char *explain_strcoll(const char *s1, const char *s2);

The explain_strcoll function is used to obtain an explanation of an error returned by the strcoll(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.

s1
The original s1, exactly as passed to the strcoll(3) system call.
s2
The original s2, exactly as passed to the strcoll(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:

errno = 0; int result = strcoll(s1, s2);
if (result < 0 && errno != 0)
{
fprintf(stderr, "%s\n", explain_strcoll(s1, s2));
    exit(EXIT_FAILURE);
}

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

explain_errno_strcoll

const char *explain_errno_strcoll(int errnum, const char *s1, const char *s2);

The explain_errno_strcoll function is used to obtain an explanation of an error returned by the strcoll(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.
s1
The original s1, exactly as passed to the strcoll(3) system call.
s2
The original s2, exactly as passed to the strcoll(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:

errno = 0; int result = strcoll(s1, s2);
if (result < 0 && errno != 0)
{
    int err = errno;
fprintf(stderr, "%s\n", explain_errno_strcoll(err, s1, s2));
    exit(EXIT_FAILURE);
}

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

explain_message_strcoll

void explain_message_strcoll(char *message, int message_size, const char *s1, const char *s2);

The explain_message_strcoll function is used to obtain an explanation of an error returned by the strcoll(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.
s1
The original s1, exactly as passed to the strcoll(3) system call.
s2
The original s2, exactly as passed to the strcoll(3) system call.

Example: This function is intended to be used in a fashion similar to the following example:

errno = 0; int result = strcoll(s1, s2);
if (result < 0 && errno != 0)
{
    char message[3000];
explain_message_strcoll(message, sizeof(message), s1, s2);
    fprintf(stderr, "%s\n", message);
    exit(EXIT_FAILURE);
}

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

explain_message_errno_strcoll

void explain_message_errno_strcoll(char *message, int message_size, int errnum, const char *s1, const char *s2);

The explain_message_errno_strcoll function is used to obtain an explanation of an error returned by the strcoll(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.
s1
The original s1, exactly as passed to the strcoll(3) system call.
s2
The original s2, exactly as passed to the strcoll(3) system call.

Example: This function is intended to be used in a fashion similar to the following example:

errno = 0; int result = strcoll(s1, s2);
if (result < 0 && errno != 0)
{
    int err = errno;
    char message[3000];
explain_message_errno_strcoll(message, sizeof(message), err, s1, s2);
    fprintf(stderr, "%s\n", message);
    exit(EXIT_FAILURE);
}

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

COPYRIGHT

libexplain version 1.4
Copyright (C) 2013 Peter Miller