Why does bash print exit even when it does not exit - is this a bug?

Question

exit with zero or one numeric argument like exit or exit 42 print "exit" and exit the shell.

exit with an invalid argument like exit hello prints an error message, prints "exit" and exits the shell with return value 255.

exit in a pipe, for example exit | cat | exit does not print "exit" and the return value of this command depends on which version of bash we're using. This does not exit the shell.

exit with multiple arguments, like, exit 1 2 3 prints an error message, prints "exit" but does not exit the shell.

This means that sometimes bash will print "exit" without actually exiting, which can be very confusing. Is this a bug or does this make sense for some reason?

Answer 1

Bash prints "exit" when it is about to exit a non-login shell, and prints "logout" (or equivalent in a locale used) when it is about to exit a login shell. Therefore I guess that this message is printed exactly to distinguish these two cases from user point of view (when you log out from eg. a ssh session to a remote system and return to the local one, such an information may be helpful, if your system prompt does not include the hostname).

The case you mentioned (exit 1 2 3), where bash prints "exit" but does not exit (and prints an error message instead, after printing "exit") should be considered a design error, I think. exit should parse arguments and print an optional error message before printing "exit" or "logout". The latter should be printed only in case of a successful parameter check. You can file a bug if you think this is confusing.