Well, I'm not sure the additional exit codes are useful enough to justify that the change possible breaks scripts of many users.

Suggestion to print errors on stderr is good. But again, probably optionally only. I have to think about it.

Add to tracker:
https://winscp.net/tracker/742
https://winscp.net/tracker/741

Also, it would be nice if errors were written to stderr.

This feature request would affect WinSCP.com.

When WinSCP or a script fails the exit code is 1 instead of 0. If the user wants to know how the script failed, they must grep the output or parse the XML log. Depending on the environment, this can be somewhat difficult. IMHO, it would be beneficial to have more error codes, so that user can immediately know why their script has failed.

Maybe three exit codes could be used: 0 for normal, 1 for SSH/SFTP related errors (network, protocol, etc), and 2 for script errors (bad command syntax and/or bad exit codes from "call"s). Something like that.