If a command terminates abnormally, i.e. not by exit or interrupt, osh reports the cause and also if a core file has been dumped. This can be used especially within a redirection or pipe. If an argument not beginning with '-' is supplied to the shell, its contents are taken as input to the shell. If the shell detects an error or it receives a signal, it terminates. If osh has detected a syntax error and is then exited, it returns 1.
Much silly behavior is implemented for compatibility, including error-messages.
Because osh does not read any startup files, do not use it as a login shell unless you know what you are doing. Some features of the original UNIX 6th Edition shell are undocumented in its manual page and are left undocumented here, too. This document was created by man2html , using the manual pages.