COHERENT manpages
This page displays the COHERENT manpage for ttys [Describe terminal ports].
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ttys -- System Administration Describe terminal ports /etc/ttys File /etc/ttys describes the terminals in the COHERENT system. The process init reads this file when it brings up the system in multi-user mode. /etc/ttys contains one line for each terminal. Each line consists of the following four fields: 1. The first field is one character long, and indicates if the device is enabled for logins: `0' indicates that the device is not enabled, and `1' (one) indicates that logins are enabled for the device. 2. The second field is one character long, and indicates whether the device is local (i.e., a terminal) or remote (i.e., a modem): `r' indicates remote, and `l' (lower-case L) indicates local. If the port is named in file /etc/dialups, then the command login checks the file /etc/d_passwd to see if the program the user is invoking is protected by a password. If so, it prompts the user for that additional password before allowing her to log in. For details, see the Lexicon entries for login, dialups, and d_passwd. 3. The third field is one character long, and sets the baud rate for the device. Note that a device can have either a fixed baud rate, or a variable baud rate. The following table gives the codes for fixed baud rates: C 110 G 300 I 1200 L 2400 N 4800 P 9600 Q 19200 S 38400 The common variable-speed codes terminal types are as follows: 0 300, 1200, 150, 110 3 2400, 1200, 300 When a user dials into a variable-speed line, a message is sent to the terminal using the first speed listed. If the message is unintelligible, the user hits the <break> key and the system tries the next speed; and so on, until the correct speed is selected. 4. The fourth field names the port that this device is plugged into. The following table names the ports that COHERENT recognizes: console The console device colorN Virtual console device N, color console monoN Virtual console device N, monochrome console comNl Serial port comN, local device comNr Serial port comN, remote device comNfl Serial port comN, local device, flow control comNfr Serial port comN, remote device, flow control comNpl Serial port comN, local polled device comNpr Serial port comN, remote polled device Note that if field 2 (described above) says that this is a local device, then you must use a port descriptor that ends in `l'; likewise, if field 2 states that this is a remote device, the port descriptor must end in `r'. Doing otherwise will result in trouble. See Lexicon entry asy for details. Note also that you must use a device with hardware flow control (i.e., a device whose suffix includes the letter `f') if you wish to use a high-speed modem (e.g., 14.4bis). Do not leave trailing spaces at the end of an entry in /etc/ttys. Leaving blanks at the end of a line usually results in errors that state that a device could not be found. After you have edited /etc/ttys, the following command forces COHERENT to re-read the file and use the new descriptions: kill quit 1 Examples Consider the following ttys entry: 1lPconsole Field 1 is the first character. Here it is set to `1' (one), which indicates that the device is enabled for logins. Field 2 is the second character. Here it is set to `l' (lower-case L), which indicates that this is a local device. Field 3 is the third character. Here, it is set to `P', which indicates that the device operates at the fixed baud rate of 9600 baud. This field is ignored by the console device driver since the console is not a serial device. Finally, field 4 is the remainder of the line. Here, it indicates that the device in question is the console. Now, consider another example: 1r3com3r Field 1 is the first character. Here it is set to `1' (one), which indicates that the device is enabled for logins. Field 2 is the second character. Here it is set to `r', which indicates that this is a remote device, i.e., a modem. Field 3 is the third character. Here, it is set to `3', which indicates that the device operates at variable baud rates of 2400, 1200, and 300. By hitting the <break> key on the terminal, the user can select from among those three baud rates, in that order. Finally, field 4 is the remainder of the line. Here, it indicates that the device in question is plugged into port com3, and is accessed via special file /dev/com3r. Files /etc/ttys See Also Administering COHERENT, asy, d_passwd, dialups, getty, init, login, stty, terminal, tty Notes If you wish to enable logins on a COM port on which you will also be dialing out, you must edit file /etc/ttys and add a line for the raw device. For example, if you have a modem plugged into COM1 and you wish to dial out on that port, you must have an entry for both com1l and com1r. Note that the entry for com1r must precede the entry for com1l. If you do not do this, the commands cu and uucico cannot disable com1r before they dial out on com1l. cu also requires that the device /dev/console appear last in file /etc/ttys. If this is not so, cu refuses to disable the enabled port or dial out.