ERR_GET_ERROR(3ossl)

💖 NAME 💖

ok so bestie, this is ERR_GET_ERROR(3ossl) and it's literally your whole toolkit for grabbing error codes and the lil data that comes attached to them 🫶

The squad is: ERR_get_error, ERR_peek_error, ERR_peek_last_error, ERR_get_error_line, ERR_peek_error_line, ERR_peek_last_error_line, ERR_peek_error_func, ERR_peek_last_error_func, ERR_peek_error_data, ERR_peek_last_error_data, ERR_get_error_all, ERR_peek_error_all, ERR_peek_last_error_all, ERR_get_error_line_data, ERR_peek_error_line_data, ERR_peek_last_error_line_data — and what they do is obtain error code and data. that's the whole vibe ✨

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🌸 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_peek_error_line(const char **file, int *line);
unsigned long ERR_peek_last_error_line(const char **file, int *line);

unsigned long ERR_peek_error_func(const char **func);
unsigned long ERR_peek_last_error_func(const char **func);

unsigned long ERR_peek_error_data(const char **data, int *flags);
unsigned long ERR_peek_last_error_data(const char **data, int *flags);

unsigned long ERR_get_error_all(const char **file, int *line,
                                const char **func,
                                const char **data, int *flags);
unsigned long ERR_peek_error_all(const char **file, int *line,
                                 const char **func,
                                 const char **data, int *flags);
unsigned long ERR_peek_last_error_all(const char **file, int *line,
                                      const char *func,
                                      const char **data, int *flags);

and now the part where we say goodbye 👋 the following functions have been deprecated since OpenSSL 3.0, and they can be hidden entirely by defining OPENSSL_API_COMPAT with a suitable version value — peep openssl_user_macros(7) for that:

unsigned long ERR_get_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);

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👑 DESCRIPTION 👑

ERR_get_error() returns the earliest error code from the thread's error queue and removes the entry. the way this one works is you can call it over and over again until there are literally no more error codes left to return 🔁

ERR_peek_error() returns the earliest error code from the thread's error queue without modifying it. look but don't touch energy 💅

ERR_peek_last_error() returns the latest error code from the thread's error queue without modifying it. it's giving "most recent drama, unread" 😌

See ERR_GET_LIB(3) for obtaining further specific information such as the reason of the error, and ERR_error_string(3) for human-readable error messages. go read those, iykyk.

ERR_get_error_all() is the same as ERR_get_error(), but on success it additionally stores the filename, line number and function where the error occurred in *file, *line and *func, and also extra text and flags in *data, *flags. If any of those parameters are NULL, it will not be changed. An unset filename is indicated as "", i.e. an empty string. An unset line number is indicated as 0. An unset function name is indicated as "", i.e. an empty string. 🎀

A pointer returned this way by these functions and the ones below is valid until the respective entry is overwritten in the error queue. so like, use it while it's hot 🔥

ERR_peek_error_line() and ERR_peek_last_error_line() are the same as ERR_peek_error() and ERR_peek_last_error(), but on success they additionally store the filename and line number where the error occurred in *file and *line, as far as they are not NULL. An unset filename is indicated as "", i.e., an empty string. An unset line number is indicated as 0.

ERR_peek_error_func() and ERR_peek_last_error_func() are the same as ERR_peek_error() and ERR_peek_last_error(), but on success they additionally store the name of the function where the error occurred in *func, unless it is NULL. An unset function name is indicated as "".

ERR_peek_error_data() and ERR_peek_last_error_data() are the same as ERR_peek_error() and ERR_peek_last_error(), but on success they additionally store additional data and flags associated with the error code in *data and *flags, as far as they are not NULL. Unset data is indicated as "". In this case the value given for the flag is irrelevant (and equals 0). *data contains a string if *flags&ERR_TXT_STRING is true. ✨

ERR_peek_error_all() and ERR_peek_last_error_all() are combinations of all of the above. it's the everything bagel 🥯

ERR_get_error_line(), ERR_get_error_line_data(), ERR_peek_error_line_data() and ERR_peek_last_error_line_data() are older variants of ERR_get_error_all(), ERR_peek_error_all() and ERR_peek_last_error_all(), and may give confusing results. They should no longer be used and are therefore deprecated. bestie, don't 💀

🚨 An application MUST NOT free the *data pointer (or any other pointers returned by these functions) with OPENSSL_free() as freeing is handled automatically by the error library. do NOT do it. the library got it, she's handling it, sit down 🫶

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🌈 RETURN VALUES 🌈

The error code, or 0 if there is no error in the queue. that's it, that's the tea 🍵

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🦋 SEE ALSO 🦋

• ERR_error_string(3)
• ERR_GET_LIB(3)

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⭐ HISTORY ⭐

ERR_peek_error_func(), ERR_peek_last_error_func(), ERR_peek_error_data(), ERR_peek_last_error_data(), ERR_peek_error_all() and ERR_peek_last_error_all() were added in OpenSSL 3.0. new girls on the block 💅

ERR_get_error_line(), ERR_get_error_line_data(), ERR_peek_error_line_data() and ERR_peek_last_error_line_data() became deprecated in OpenSSL 3.0. retired, respectfully 🎀

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💜 COPYRIGHT 💜

Copyright 2000-2022 The OpenSSL Project Authors. All Rights Reserved.

Licensed under the Apache License 2.0 (the "License"). You may not use this file except in compliance with the License. You can obtain a copy in the file LICENSE in the source distribution or at <https://www.openssl.org/source/license.html>.

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and that's a wrap, my love 💖 this page is from OpenSSL 3.5.9, dated 2026-09-29, and it lives under ERR_GET_ERROR(3ossl). go forth and check your error queue, queen 👑✨