Q: I was compiling kernel using GNU Screen utility but something happened during the compilation and I want to see full error’s output but I can’t just scrollback using Ctrl+PageUp. How to scrollback in GNU Screen?
A: In GNU Screen press Ctrl + a + [ to enter Copy Mode, then scroll up/down using keys j or k. Below are some other navigation keys:
h - Move the cursor left by one character j - Move the cursor down by one line k - Move the cursor up by one line l - Move the cursor right by one character 0 - Move to the beginning of the current line $ - Move to the end of the current line. G - Moves to the specified line (defaults to the end of the buffer). C-u - Scrolls a half page up. C-b - Scrolls a full page up. C-d - Scrolls a half page down. C-f - Scrolls the full page down.
By the way, in order to define scrollback buffer size start screen with the following key (5000 lines in this example):
screen -h 5000
Quick info about GNU Screen utility: it is Unix tool that allows to run multiple applications in several “virtual” windows. It is very useful when you need, let’s say, to see hardware resources consumption caused by started application in different console etc. GNU screen is also good option to run applications remotely via ssh: just run application in screen and log off until it’s finished, then just “pick up” screen session and see how the application’s output.
Update: You can use activate copy mode of GNU Screen also by Ctrl + Esc that might be more useful than Ctrl + a + [ shortcut (thanks to Yu-Jie Lin for this tip).