Upper case username login through modem

[Jun Zhang_4]

When LOGIN is prompted, type USERNAME,
\PASSWORD will be prompted, type password, now I'll be told "Login incorrect".
I then added IUCLC in the before connect string of the gettydefs entry, the prompts are fine,
loing:
Password:
typing USERNAME at the loggin prompt, it will be echoed with all lowercase, and login will fail.
No login issue for lowercase usernames.

[Bill Hassell · Accepted solution]

This a historical 'feature' of Unix. In the very old days, some terminals (known as teletypewriters hence tty as a Unix term) were only UPPERCASE...there was no lowercase capability at all. To allow use of these devices, an all UPPERCASE username triggered an stty change that caused every character on input and output to be UPPERCASE. This is documented in: man getty

"The user's name is scanned to see if it contains any lowercase alphabetic characters; if not, and if the name is non-empty, the system is told to map any future uppercase characters into the corresponding lowercase characters."

This is a getty feature, and therefore, all UPPERCASE usernames should never be used. This is not the case for a telnet login, only trough a serial terminal or modem connection where getty is involved.

[Jun Zhang_4]

Do you have knowlege if mgetty any better?

Jun

[Rodney Hills]

The work around is to enter a lowercase text (anything will do) press enter. Then enter a null password.

The system will say not a valid user/password of course, but now you can type a full uppercase name without the "case swapping".

HTH

-- Rod Hills