ERR_PRINT_ERRORS(3ossl)

💖 ERR_PRINT_ERRORS 💖

okay bestie, gather round, because today we're talking about the OpenSSL error-printing girlies. this is ERR_PRINT_ERRORS(3ossl) from the OpenSSL manual, and it's literally just "how do i get the errors OUT of the queue and onto my screen" — and honestly? iconic. 🌸

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✨ NAME ✨

ERR_print_errors, ERR_print_errors_fp, ERR_print_errors_cb — print error messages. that's it. that's the whole job. no cap. 💅

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🎀 SYNOPSIS 🎀

#include <openssl/err.h>

void ERR_print_errors(BIO *bp);
void ERR_print_errors_fp(FILE *fp);
void ERR_print_errors_cb(int (*cb)(const char *str, size_t len, void *u),
                         void *u);

look at her. three little functions. all void. all serving. 👑

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🦋 DESCRIPTION 🦋

so here's the tea, bestie. 🫖

• ERR_print_errors() — this one's the convenience function, the "i don't have time to be fancy" queen. she prints the error strings for all the errors that OpenSSL has recorded over to bp, and in doing so she empties the error queue. gone. cleared. she ate and left no crumbs. 💀
• ERR_print_errors_fp() — same energy, same everything, except the output goes to a FILE instead. that's the only glow-up. ✨
• ERR_print_errors_cb() — same again, except instead of dumping to a stream she calls the callback function, cb, once for each error line. she passes the string, the length, and the userdata u as the callback parameters. very "i'll let you handle the vibes" of her. 🧚

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🌈 the format, and yes it's specific 🌈

the error strings will have the following format:

[pid]:error:[error code]:[library name]:[function name]:[reason string]:[filename]:[line]:[optional text message]

let's break it down, because the details matter:

• error code is an 8 digit hexadecimal number. eight. digits. hexadecimal. write that down. 📝
• library name, function name and reason string are ASCII text — and so is optional text message, if one was set for the respective error code. so like, only sometimes does that last one show up. it's giving "optional but make it mysterious". 🙈

and here's the important bit, no skipping: if there is no text string registered for the given error code, the error string will contain the numeric code instead. so you're never left with nothing. she always shows up. 💜

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⭐ RETURN VALUES ⭐

• ERR_print_errors() and ERR_print_errors_fp() return no values.

that's right. nothing. void. they simply do the thing and walk away. main character energy fr fr. 💅✨

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🔥 SEE ALSO 🔥

• ERR_error_string(3)
• ERR_get_error(3)

go read those next, bestie, they're the sister pages and they also slay. 👑

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👑 COPYRIGHT 👑

Copyright 2000-2020 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 the page!! 🎀 this was ERR_PRINT_ERRORS(3ossl) from OpenSSL 3.5.9, dated 2026-09-29 — go forth and empty those error queues, gorgeous. mwah. 💖🦋🌸