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Bash prompt linewrap with colors issues

linux, bash, linux, prompt1 min read

So I've been fighting with trying to make a custom color prompt for a while now.

I've recently found out about tput to output color codes. That combined with local variables meant prompts became easier to read.

local BG_RED=$(tput setab 1)

We started to create a custom prompt here for the team. Had all the info needed at a quick glance. Everything was good except long lines didn't wrap properly. Ctrl+r would just get nutty.

So, after a lot of research and reading various forum posts, I found out that color codes should be wrapped in "\\[...\\]". So example:

local BG_CYAN=$(tput setab 6)
local FG_GREEN=$(tput setaf 2)
local RESET=$(tput sgr0)
export PS1="\[${BG_CYAN}${FG_GREEN}\]\u@\h \[${RESET}\]$"

Note the \\[ and \\] wrapping the codes. This allows bash to properly figure out the length of the line. Note: I just grabbed random colors, I suspect this example looks bad.

I did find a slight exception

For the TITLEBAR (putty/xterm/screen) support:

case $TERM in

The [ and ] should wrap the entire block as everything inside is considered part of the control code.

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