[SOLVED] BASH $PS1 Hack

cryingthug · 02-11-2011, 08:08 PM

I would like to put a variable in the $PS1 prompt that will change each time a command is run. I want the color of the $PS1 prompt to change each time a command is run.

I know that I can do this:

Code:

PS1="\h@\w \# " 

## "\#" is changes every time a command is run

But I would like to do this: ( but it does not work )

Code:

var=$(for var in 1 2 3 4 5 6 ; do echo $var; done)

PS1="\[\033\[\4"$var";3m\] \h@\w \[\033[00m\] "

Does this make sense to you guys/girls?

konsolebox · 02-11-2011, 09:01 PM

perhaps it should be:

Code:

PS1=$'\[\033\[\4'$var$';3m\] \h@\w \[\033[00m\] '

cryingthug · 02-11-2011, 09:13 PM

I'll try that.....

Quote:

Originally Posted by konsolebox

perhaps it should be:

Code:

PS1=$'\[\033\[\4'$var$';3m\] \h@\w \[\033[00m\] '

cryingthug · 07-17-2011, 03:22 PM

konsolebox:

Your suggestion did not work.

Reuti · 07-17-2011, 03:58 PM

The var assignment you used will not create an array but just one variable. If you would like to use an array you could use:

Code:

$ var=(1 2 3 4 5 6)

But you don’t it here anyway. To change the color with each return, it needs to be put in PROMPT_COMMAND:

Code:

$ PROMPT_COMMAND='let var++; if [ "$var" -gt 6 ]; then var=1; fi; PS1="\[\e[0;3${var}m\]\u@\h:\w> \[\e[m\]"'

Reuti · 07-17-2011, 04:11 PM

Add-on to skip the if:

Code:

$ PROMPT_COMMAND='let "var=++var>6?1:var"; PS1="\[\e[0;3${var}m\]\u@\h:\w> \[\e[m\]"'

cryingthug · 07-17-2011, 04:24 PM

Reuti:

THANK YOU!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Quote:

Originally Posted by Reuti

Add-on to skip the if:

Code:

$ PROMPT_COMMAND='let "var=++var>6?1:var"; PS1="\[\e[0;3${var}m\]\u@\h:\w> \[\e[m\]"'

I just could not figure it out. I was trying to do it another more complex way. Well, we learn something new everyday.

cryingthug · 07-17-2011, 06:21 PM

Reuti:

It works but do you know how to connect the change in colour to this "\!" ? That is the history sequence. That way the colour will only change if a command is actually run. Right now the colour changes anytime I press the "Enter" key.

Quote:

Originally Posted by Reuti

Add-on to skip the if:

Code:

$ PROMPT_COMMAND='let "var=++var>6?1:var"; PS1="\[\e[0;3${var}m\]\u@\h:\w> \[\e[m\]"'

Reuti · 07-18-2011, 04:33 AM

Well, there is the environment variable HISTCMD which gives the number of the actual entry in the history file and one can check whether it changed. Unfortunately (and nevertheless interesting) this variable always resolves to 1 inside the PROMPT_COMMAND statement(s).

So, for now I have no idea how to achieve it.

colucix · 07-18-2011, 05:01 AM

Code:

PROMPT_COMMAND='cmd="$(tail -1 ~/.bash_history)"; history -a; if [[ "$(tail -1 ~/.bash_history)" != "$cmd" ]]; then let "var=++var>6?1:var"; fi; PS1="\[\e[0;3${var}m\]\u@\h:\w> \[\e[m\]"'

This changes colour only if you enter a command different from the previous one. Pressing enter alone has no effect (colour doesn't change). The history -a command append the new history line to the history file.

cryingthug · 10-02-2011, 08:30 PM

I came up with this with the help of you guys.

Code:

let n=232

    _cmd(){
        if [ "$n" -lt 255 ] ; then
            let n++
        else
            let n=232
        fi
        PS1="\[\033[38;05;${n}m\][\t] \h \w \! \$ \[\033[00m\] " 
    }
    PROMPT_COMMAND=_cmd