NAME
ERR_get_error, ERR_peek_error, ERR_peek_last_error, ERR_get_error_line, ERR_peek_error_line, ERR_peek_last_error_line, ERR_get_error_line_data, ERR_peek_error_line_data, ERR_peek_last_error_line_data — obtain error code and data 
Synopsis
#include <openssl/err.h> 
unsigned
long ERR_get_error(void); 
unsigned long ERR_peek_error(void); 
unsigned
long ERR_peek_last_error(void); 
unsigned long ERR_get_error_line(const
char **file, int *line); 
unsigned long ERR_peek_error_line(const
char **file, int *line); 
unsigned long ERR_peek_last_error_line(const
char **file, int *line); 
unsigned long ERR_get_error_line_data(const
char **file, int *line, const char **data, int *flags); 
unsigned
long ERR_peek_error_line_data(const char **file, int *line, const
char **data, int *flags); 
unsigned long ERR_peek_last_error_line_data(const
char **file, int *line, const char **data, int *flags);
DESCRIPTION
ERR_get_error() returns the earliest error code from the thread's
error queue and removes the entry. This function can be called repeatedly
until there are no more error codes to return. 
ERR_peek_error() returns the earliest error code from the
thread's error queue without modifying it. 
ERR_peek_last_error() returns the latest error code from the
thread's error queue without modifying it. 
See ERR_GET_LIB(3) for obtaining information
about location and reason of the error, and ERR_error_string(3) for
human-readable error messages. 
ERR_get_error_line(), ERR_peek_error_line() and ERR_peek_last_error_line()
are the same as the above, but they additionally store the file
name and line number where the error occurred in *file and
*line, unless these are NULL. 
ERR_get_error_line_data(), ERR_peek_error_line_data() and
ERR_get_last_error_line_data() store additional data and flags associated
with the error code in *data and *flags,
unless these are NULL. *data contains
a string if *flags&ERR_TXT_STRING.
If it has been allocated by OPENSSL_malloc(), *flags&ERR_TXT_MALLOCED is
true. 
RETURN VALUES
The error code, or 0 if there is no error in the queue. 
SEE ALSO
err(3), ERR_error_string(3), ERR_GET_LIB(3) 
HISTORY
ERR_get_error(), ERR_peek_error(), ERR_get_error_line() and
ERR_peek_error_line() are available in all versions of SSLeay and
OpenSSL. ERR_get_error_line_data() and ERR_peek_error_line_data()
were added in SSLeay 0.9.0. ERR_peek_last_error(), ERR_peek_last_error_line()
and ERR_peek_last_error_line_data() were added in OpenSSL 0.9.7.