Describe the bug
First of all, I'm so sorry for my poor english.
I found this bug when I running a example source.

https://github.com/libssh2/libssh2/blob/master/example/ssh2_exec.c#L263
At this line, the condition is rc == LIBSSH2_ERROR_EAGAIN.
And with this condition, the program can't read the responses properly.

So I suggest you to change the condition to "nread == LIBSSH2_ERROR_EAGAIN".

Version (please complete the following information):

• OS and version: Linux version 5.15.0-1037-oracle (buildd@bos02-arm64-053) (gcc (Ubuntu 11.3.0-1ubuntu1~22.04.1) 11.3.0, GNU ld (GNU Binutils for Ubuntu) 2.38) #43-Ubuntu SMP Tue Jun 6 16:21:24 UTC 2023
• libssh2 version: Master branch (commit 766bde9)
• crypto backend and version:
  • OpenSSL 3.0.2 15 Mar 2022 (Library: OpenSSL 3.0.2 15 Mar 2022)
  • zlib1g-dev/jammy-updates,jammy-security,now 1:1.2.11.dfsg-2ubuntu9.2 arm64 (I'm not sure whether this is the ZLIB or not. sry)

Additional context
Would you check other examples?
The same bug may exist.
And always thank you for your porject.