char *ERR_error_string(unsigned long e, char *buf);
void ERR_error_string_n(unsigned long e, char *buf, size_t len);
const char *ERR_lib_error_string(unsigned long e);
const char *ERR_func_error_string(unsigned long e);
const char *ERR_reason_error_string(unsigned long e);
DESCRIPTION
ERR_error_string() generates a human-readable string representing the
error code e, and places it at
buf. buf must be at least 120 bytes long. If
buf is NULL, the error string is placed in a static
buffer. ERR_error_string_n() is a variant of ERR_error_string() that
writes at most len characters
(including the terminating 0) and truncates the string if necessary.
For ERR_error_string_n(), buf may
not be NULL.
error code is an 8 digit
hexadecimal number, library name,
function name and reason string are ASCII text.
ERR_lib_error_string(), ERR_func_error_string() and
ERR_reason_error_string() return the library name, function name and
reason string respectively.
The OpenSSL error strings should be loaded by calling ERR_load_crypto_strings(3)
or, for SSL applications, SSL_load_error_strings(3)
first. If there is no text string registered for the given error
code, the error string will contain the numeric code.
ERR_print_errors(3)
can be used to print all error codes currently in the queue.
RETURN VALUES
ERR_error_string() returns a pointer to a static buffer containing
the string if buf== NULL, buf otherwise.
ERR_lib_error_string(), ERR_func_error_string() and
ERR_reason_error_string() return the strings, and NULL if none is registered for the error code.