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atanunq / viuer

Rust library for displaying images in the terminal.
MIT License
253 stars 46 forks source link

Detect iTerm protocol from $LC_TERMINAL too #36

Closed nopdotcom closed 2 years ago

nopdotcom commented 2 years ago

When checking whether the iTerm protocol is available, check the LC_TERMINAL environment variable in addition to TERM_PROGRAM. LC_TERMINAL is passed to many remote hosts; read on for details.

iTerm2 sets the environment variable LC_TERMINAL to iTerm2. This is useful because on Debian and Ubuntu systems*, the default /etc/ssh/sshd_config contains the line:

AcceptEnv LANG LC_*

That is, if the ssh client sends the LC_TERMINAL variable, it will be added to the login environment. macOS has this configuration in /etc/ssh/sshd_config.d/100-macos.conf as well. macOS's default /etc/ssh/ssh_config contains

Host *
    SendEnv LANG LC_*

so macOS ssh clients all pass LC_TERMINAL. Debian and Ubuntu do this too.

*: Checked Ubuntu 16.04, 18.04, 20.04, 22.04; Debian 9.9, 10.12, 11.3, current sid.

atanunq commented 2 years ago

Thank you for the detailed explanation, TIL