ERR_GET_ERROR(3SSL)

📦
version 4.0.3 · 13 versions
, in ubuntu stonking

💖 NAME 💖

okay so bestie, meet the whole squad: 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, and ERR_peek_last_error_line_data.

Their whole job? obtain error code and data ✨ yep that's it, that's the function family. And this page is the ERR_GET_ERROR(3SSL) manual from OpenSSL, so you're in the right place, don't stress 🫶

🎀 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);
⚠️ okay heads up, the following ones are deprecated since OpenSSL 3.0 and can be hidden entirely by defining OPENSSL_API_COMPAT with a suitable version value — peep openssl_user_macros(7) for the tea:
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);

🦋 DESCRIPTION 🦋

So the thread's error queue is like… a little group chat of everything that went wrong, and these functions are how you read it. Here's the vibe check on each:

  • ERR_get_error() — returns the earliest error code from the thread's error queue and removes the entry. So it's giving "read and delete" 💅 you can call it over and over until there are literally no more error codes to return.
  • ERR_peek_error() — returns the earliest error code from the thread's error queue without modifying it. Just a lil peek, no take-backs 🥺
  • ERR_peek_last_error() — returns the latest error code from the thread's error queue without modifying it. The newest drama, untouched.
  • Need the actual why? Run, don't walk, to 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 🫶
  • ERR_get_error_all() — 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.
🫧 important: a pointer returned this way by these functions and the ones below is valid until the respective entry is overwritten in the error queue. That's the main character's lifespan, bestie, don't hold onto it forever.
  • ERR_peek_error_line() and ERR_peek_last_error_line() — 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() — 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() — 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() — they're literally combinations of all of the above. The full deluxe bundle ✨
  • ERR_get_error_line(), ERR_get_error_line_data(), ERR_peek_error_line_data() and ERR_peek_last_error_line_data() — these are older variants of ERR_get_error_all(), ERR_peek_error_all() and ERR_peek_last_error_all(), and ngl, they may give confusing results 😭 They should no longer be used and are therefore deprecated. It's giving legacy, it's giving red flag, we don't use her anymore, periodt.
🛑 THE BIG ONE: 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, I am begging you, do NOT free it yourself. The library has it, she's got it handled 💖

🌸 RETURN VALUES 🌸

The error code, or 0 if there is no error in the queue. That's it, that's the answer. 0 = queue is empty, no thoughts, head empty, nothing to report 🕳️

💜 SEE ALSO 💜

⭐ 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 — glow up era 🎀
  • 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. They had a good run, lowkey 💀

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>.

okay bestie that's the whole page, you ate it up 💅 this was ERR_GET_ERROR(3SSL), straight from OpenSSL, version 4.0.3, dated 2026-09-29. go forth and read your error queue like the icon you are 🦋✨

📦 where this page comes from