A/UX: mail and "not a typewriter" (2/95)

What does "not a typewriter" mean when sending mail in A/UX?

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The "user unknown: not a typewriter" error message is most likely caused by the sendmail program mapping the user's name to lowercase before checking /etc/password for the user's account. For example, a username of Mike or Jim would be mapped to 'mike' or 'jim', and then the passwd file is checked for those names. This is the way login names are supposed to appear in the passwd file.

The solution would be to create a username in the passwd file all in lowercase. "Jim" would have an entry of "jim" as well.

The error saying "not a typewriter" is a historical error. The text for this error message was created when the terminals attached to the system were teletypes. The error is saying that there is no terminal attached to the process where the process can send messages generated by either STDIO (standard output) or STDERR (standard error). This message is common on processes that are started from a script, from cron, or from inittab. It can also be encountered if a process is started as a background process. If the process generates any kind of output, the message "not a typewriter" is displayed.

Article Change History:
27 Feb 1995 - Added historic information on "not a typewriter".

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Дата публикации: Feb 19, 2012