1=pod
2
3=head1 NAME
4
5ERR_error_string, ERR_error_string_n, ERR_lib_error_string,
6ERR_func_error_string, ERR_reason_error_string - obtain human-readable
7error message
8
9=head1 SYNOPSIS
10
11 #include <openssl/err.h>
12
13 char *ERR_error_string(unsigned long e, char *buf);
14 void ERR_error_string_n(unsigned long e, char *buf, size_t len);
15
16 const char *ERR_lib_error_string(unsigned long e);
17 const char *ERR_func_error_string(unsigned long e);
18 const char *ERR_reason_error_string(unsigned long e);
19
20=head1 DESCRIPTION
21
22ERR_error_string() generates a human-readable string representing the
23error code I<e>, and places it at I<buf>. I<buf> must be at least 256
24bytes long. If I<buf> is B<NULL>, the error string is placed in a
25static buffer.
26Note that this function is not thread-safe and does no checks on the size
27of the buffer; use ERR_error_string_n() instead.
28
29ERR_error_string_n() is a variant of ERR_error_string() that writes
30at most I<len> characters (including the terminating 0)
31and truncates the string if necessary.
32For ERR_error_string_n(), I<buf> may not be B<NULL>.
33
34The string will have the following format:
35
36 error:[error code]:[library name]:[function name]:[reason string]
37
38I<error code> is an 8 digit hexadecimal number, I<library name>,
39I<function name> and I<reason string> are ASCII text.
40
41ERR_lib_error_string(), ERR_func_error_string() and
42ERR_reason_error_string() return the library name, function
43name and reason string respectively.
44
45If there is no text string registered for the given error code,
46the error string will contain the numeric code.
47
48L<ERR_print_errors(3)> can be used to print
49all error codes currently in the queue.
50
51=head1 RETURN VALUES
52
53ERR_error_string() returns a pointer to a static buffer containing the
54string if I<buf> B<== NULL>, I<buf> otherwise.
55
56ERR_lib_error_string(), ERR_func_error_string() and
57ERR_reason_error_string() return the strings, and B<NULL> if
58none is registered for the error code.
59
60=head1 SEE ALSO
61
62L<ERR_get_error(3)>,
63L<ERR_print_errors(3)>
64
65=head1 COPYRIGHT
66
67Copyright 2000-2017 The OpenSSL Project Authors. All Rights Reserved.
68
69Licensed under the OpenSSL license (the "License").  You may not use
70this file except in compliance with the License.  You can obtain a copy
71in the file LICENSE in the source distribution or at
72L<https://www.openssl.org/source/license.html>.
73
74=cut
75