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Aquarius Power
Asked: 2013-05-10 16:08:05 +0800 CST

how to be warned if terminal has sudo privileges and also show how much time is left?

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How to see in the terminal that you have sudo privileges? (so knowing I have these privileges, I can just type sudo -k) It would be better to not add too much information into the terminal also, just some kind of simple and small alert!

REMAINING TIME IS IMPOSSIBLE, right?

Also, how to see how much time I still have with those privileges on that specific terminal? (so I can just let it end instead of typing sudo -k). I think that remaining time could show up each time I press Enter key.

EDIT: I researched more and found that /var/lib/sudo/$USER/$nPts (where $nPts is current terminal pts as of ps -p $$) has its timestamp updated everytime a sudo command is issued, and it is only accessible if you use a sudo command, so the remaining time will always be the configured one...

PS.: Alternatively to that, I tried alias sudo='sudo -k' but I dislike having to type the password for every command... And also, this alias sudos='sudo -k' (or alias ssudo='sudo -k', good if you typed a long line, just press Home and type 's') works if you only want to issue one command by typing sudos. But I still miss to know when I have normal sudo privileges to know I need to act...

sudo

2 Answers

  1. [I still would like to know if there is a better answear.]

    I found a way that works, and the prompt will be kept on a single line:

    at the end of your ~/.bashrc add this:

    function FUNCsudoOn() { 
    if sudo -n uptime 2>/dev/null 1>/dev/null; then 
        echo -ne "\E[0m\E[93m\E[41m\E[1m\E[5m SUDO \E[0m"; 
        #echo #without newline, the terminal seems to bugout with lines that are too big... discomment this if you find any problems...
    fi; 
}
function FUNCpromptCommand () { 
    FUNCsudoOn
}
export PROMPT_COMMAND=FUNCpromptCommand
#export PS1="\`FUNCsudoOn\`$PS1" #this also works, use instead of PROMPT_COMMAND

    EDIT: I found that sudo -n uptime will update the sudo timeout, so everytime you hit the Enter key, that sudo time will be updated... That makes knowing the remaining time useless, as it will always be the configured one, defaulting to 15min...

    and to find the best colors formatting for you taste you can use ScriptEchoColor with --escapedchars option like:

    echoc --escapedchars "@{nRlyo} SUDO " #that outputs below...
echo -e "\E[0m\E[93m\E[41m\E[1m\E[5m SUDO \E[0m"

    to just stop the blinking remove \E[5m like in \E[0m\E[93m\E[41m\E[1m SUDO \E[0m

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  2. Your terminal doesn't "have sudo privileges", unless you do something silly like sudo bash DON'T DO THIS!

    All you have to do to "have normal sudo privileges" is to refrain from typing sudo in front of the command.

    /usr/bin/id is a good way to see what sudo does. For example:

    id -a        # returns my UID info
sudo id -a   # returns root's info
id -a        # me again
sudo id -a   # root again

    The sudo man page says "The sudoers policy caches credentials for 15 minutes, unless overridden in sudoers(5)". What this means is that, by default, if you issue a sudo command (and enter your password),then wait 14.9 minutes before issuing a second sudo command, you won't have to enter your password again. If you wait 15.1 minutes, you will have to re-enter the password. sudo -k simply expires the 15 minute timer immediately. The only use I can see for sudo -k is if you're about to yield your unlocked terminal to someone you don't trust with UID 0.

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