ERR_set_mark, ERR_clear_last_mark, ERR_pop_to_mark, ERR_count_to_mark, ERR_pop - set mark, clear mark,

       Copyright 2003-2024 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>.

3.5.0                                              2025-06-04                                 ERR_SET_MARK(3SSL)

ERR_set_mark() sets a mark on the current topmost error record if there is one.

       ERR_pop_to_mark() will pop the top of the error stack until a mark is found.  The mark is then removed.
       If there is no mark, the whole stack is removed.

       ERR_clear_last_mark() removes the last mark added if there is one.

       ERR_count_to_mark() returns the number of entries on the error stack above the most recently marked
       entry, not including that entry. If there is no mark in the error stack, the number of entries in the
       error stack is returned.

       ERR_pop() unconditionally pops a single error entry from the top of the error stack (which is the entry
       obtainable via ERR_peek_last_error(3)).

ERR_count_to_mark() was added in OpenSSL 3.2.  ERR_pop() was added in OpenSSL 3.3.

       ERR_set_mark, ERR_clear_last_mark, ERR_pop_to_mark, ERR_count_to_mark, ERR_pop - set mark, clear mark,
       pop errors until mark and pop last error

ERR_set_mark() returns 0 if the error stack is empty, otherwise 1.

       ERR_clear_last_mark() and ERR_pop_to_mark() return 0 if there was no mark in the error stack, which
       implies that the stack became empty, otherwise 1.

       ERR_count_to_mark() returns the number of error stack entries found above the most recent mark, if any,
       or the total number of error stack entries.

       ERR_pop() returns 1 if an error was popped or 0 if the error stack was empty.

        #include <openssl/err.h>

        int ERR_set_mark(void);
        int ERR_pop_to_mark(void);
        int ERR_clear_last_mark(void);
        int ERR_count_to_mark(void);
        int ERR_pop(void);