Centos – How to stop Linux console output from being truncated when using Screen

Here's my .screenrc that i use everywhere to see my screen numbers as tabs at the bottom of the window and an informational line above the tabs. The part you really need is under "look and feel".

# skip the startup message
startup_message off

# go to home dir
chdir

# Automatically detach on hangup. 
autodetach on

# Change default scrollback value for new windows
defscrollback 10000

# start with visual bell as default
vbell on
vbell_msg "bell on %t (%n)"

# look and feel
caption always "%{= bb}%{+b w}%n %t %h %=%l %H %c"
hardstatus alwayslastline "%-Lw%{= BW}%50>%n%f* %t%{-}%+Lw%<"

activity "Activity in %t(%n)"

shelltitle "shell"
shell -$SHELL

You could additionally add the following to automatically add two tabs when the screen is initially created:

screen ssh usr@IP1
screen ssh usr@IP2

Also, the status content can be updated using escape codes issued from shell commands and prompts. For example, i update the status with the current directory using by using this in my .bashrc:

if [ 'screen' == "${TERM}" ]; then
  export PROMPT_COMMAND='printf "\e]2;%s %s\a" "${USER}" "${PWD}" '
fi

That's an optimisation done by screen.

When you type echo<Cr> in screen. Because of the local echo and the icrnl and onlcr settings of the pseudo terminal device in the screen window, the \r\n sequence is sent to master side (to screen).

screen implements a terminal emulator where \r is meant to bring the cursor to the beginning of the line and \n to move the cursor down. To do that, where a terminal emulator like xterm would do X API calls to move the cursor to the beginning of the line, screen has to send escape codes to the host terminals it is attached to to tell it/them to move the cursor to the left hand side of the screen window.

In case you've split the window vertically, that means send cursor positioning escape sequences to wherever the left hand side of the screen windows is. If not or if on the left hand side of the host terminal, screen would just pass those \r and \n characters along so that the cursor be moved to the beginning of the line and one line down on the host terminal as well (since all terminals treat \r and \n the same in that instance).

Now, echo runs and outputs a \n character. Because of onlcr again in the screen window tty, screen receives \r\n again. \r tells it to move to the beginning of the line, but the cursor is already at the beginning of the line, so no need to do anything which is why the host terminal doesn't receive a second \r character. Then to move the cursor down because of the \n it receives, screen sends \n to the host terminal.

You can verify that by running in screen:

printf '\r\r\r\r'

You'll notice that screen only sends one \r character to its host terminal.