vc-get-terminal 1 user commands nosh vc-get-tty set up the environment appropriate to a virtual terminal and chain vc-get-terminal --term type terminal-device-name next-prog vc-get-terminal is a chain-loading utility that sets up environment variables appropriate to a specified virtual terminal, secures the device against access by other users, and then chain loads to next-prog with the execvp3 function. next-prog may contain its own command line options, which vc-get-terminal will ignore. vc-get-terminal sets the TTY environment variable to the full device filename of the controlling terminal. Programs such as open-controlling-terminal1, and login-banner1 will make use of this environment variable as the name of the controlling terminal. It determines the terminal character device filename from the passed terminal-device-name. This can be just the absolute pathname of the device file itself or a relative pathname (such as tty1). If it is a relative pathname, vc-get-terminal tries first prefixing /dev/ and looking for a file, then prefixing /var/dev/, and then prefixing /run/dev/. In the case of the latter twain, it assumes that the virtual terminal is a user-space rather than a kernel one. vc-get-terminal sets the TERM7 environment variable to a system-dependent default for virtual terminals. For user-space virtual terminals, it also sets the COLORTERM7 environment variable similarly. It does not make any attempt to deduce terminal types or read the BSD /etc/ttys or /etc/gettytab databases. Virtual terminals are either the kernel's built-in terminal emulator or user-space virtual terminals assumed to be running console-terminal-emulator1. In both cases, the terminal type is fixed and well-known, and can be hardwired. The TERM7 variable is set to teken for the kernel's built-in terminal emulator and teken-16color for user-space virtual terminals. The COLORTERM7 variable is set to teken-256color-truecolor. In FreeBSD 9.0 the old kernel terminal emulator was replaced with the teken library, improving the escape sequence handler and enabling UTF-8 support. vc-get-terminal expects either syscons4 in its default teken mode or vt4, and does not support either the old kernel terminal emulator or syscons4 pretending to be the old kernel terminal emulator in its "cons25" mode. The TERM7 variable is set to linux-16color for all virtual terminals. Both the kernel's built-in terminal emulator and console-terminal-emulator1 are compatible with this. The COLORTERM7 variable is set to linux-256color-truecolor. The TERM7 variable is set to netbsd6 for all virtual terminals. The COLORTERM7 variable is set to netbsd6-256color-truecolor. The old pcvtXX terminal type in terminfo5 was replaced by wsvt25 in 1999, and that was replaced by netbsd6 in 2014. In theory, NetBSD also supports sun and dumb terminals. In practice, the former is unfortunately configured out on most platforms and the latter is barely even a "glass lineprinter" which does not even do what an actual lineprinter could, such as overstrike. The TERM7 variable is set to pccon for all virtual terminals. The COLORTERM7 variable is set to pccon-256color-truecolor. In theory, OpenBSD also supports sun and dumb terminals. The --term command line option is available for overriding these hardwired values, but there is little reason for using it as the terminal types for virtual terminals have not changed for several years on FreeBSD and for two and a half decades (as of 2025) on Linux. Unfortunately, the FreeBSD termcap library has not been updated with a teken entry to match its replacement kernel virtual terminal emulator. However, proper teken, teken-16color, teken-256color, linux, linux-16color, and linux-256color termcap entries for FreeBSD are supplied with the nosh toolset. They simply require a directory to be added to the list in the TERMPATH environment variable and the files to be compiled to binary form. Likewise, linux-16color was added to the Dickey terminfo database in 2009, teken was added in 2017, and teken-16color was added in 2022; but as of 2025 the terminfo database still lacks teken-256color and linux-256color. FreeBSD's mis-named xterm-clear terminal type that it employs, is incorrect. The teken library does not fully nor correctly duplicate the functionality of XTerm, the terminal type is not any kind of xterm, and other operating systems have no xterm-clear in terminfo. Do not use xterm-clear. The consequences of this are threefold: Remote access in both directions between FreeBSD and Linux systems is possible without undue difficulty, from virtual terminals on either. The Linux-based operating systems have teken-16color in terminfo and the FreeBSD systems have linux-16color in termcap. Although one cannot locally take full advantage of the 256-colour support that console-terminal-emulator1 actually has on Linux user-space virtual terminals, as there is no terminfo support; when remotely accessing FreeBSD systems linux-16color can be overridden with the linux-256color terminal type, as there is termcap support for the Linux user-space virtual terminals. If remote access to other systems from user-space virtual terminals on FreeBSD is not a concern, teken-16color can be overridden with the teken-256color terminal type. This enables full use of the 256-colour support that console-terminal-emulator1 actually has. vc-get-terminal expects to be run either directly from init1 or under a dæmon supervisor of some sort. As such, it expects to start up with an already safe environment, open file descriptors, and resource limits for a process that is running under the aegis of the superuser. To prevent a race condition in open-controlling-terminal1 (q.v.), vc-get-tty ensures that the virtual terminal is owned by the effective UID of the process, and has rw------- permissions. TERM7 terminal-types7 linux-vt4 Jonathan de Boyne Pollard