libressl-ERR_error_string3
Obtain human-readable openssl error messages
Usage
Crypto Library
(libcrypto,
-lcrypto)
char *
void
const char
*
const char
*
const char
*
Overview
ERR_error_string() generates a human-readable string representing the error code e and places it in buf. buf must be at least 256 bytes long. If buf is NULL, the error string is placed in a static buffer. Note that this function is not thread-safe and does no checks on the size of the buffer; use ERR_error_string_n() instead.
ERR_error_string_n() is a variant of ERR_error_string() that writes at most len characters (including the terminating NUL) and truncates the string if necessary. For ERR_error_string_n(), buf may not be NULL.
The string will have the following format:
error:[error code]:[library name]:[function name]:[reason string]
The error code is an 8-digit hexadecimal number. The library name, the function name, and the reason string are ASCII text.
ERR_lib_error_string(), ERR_func_error_string(), and ERR_reason_error_string() return the library name, the function name, and the 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 is NULL, or buf otherwise.
ERR_lib_error_string(), ERR_func_error_string(), and ERR_reason_error_string() return the strings, or NULL if none is registered for the error code.