Commands tagged terminal (56)

  • This command displays a clock on your terminal which updates the time every second. Press Ctrl-C to exit. A couple of variants: A little bit bigger text: watch -t -n1 "date +%T|figlet -f big" You can try other figlet fonts, too. Big sideways characters: watch -n 1 -t '/usr/games/banner -w 30 $(date +%M:%S)' This requires a particular version of banner and a 40-line terminal or you can adjust the width ("30" here). Show Sample Output

    watch -t -n1 "date +%T|figlet"
    dennisw · 2009-06-21 01:02:37 11
  • I did not know this, i'd like to share...

    open .
    vigo · 2009-06-10 10:55:20 14
  • If you enable multiuser, then you can permit others to share your screen session. The following conditions apply: 1. screen must be suid root; 2. "multiuser on" must be configured in ~/.screenrc; 3. control the others user(s) access with "aclchg": # ----- from ~/.screenrc-users ----- aclchg someuser +rx "#?" #enable r/o access to "someuser" aclchg someuser -x "#,at,aclchg,acladd,acldel,quit" # don't allow these aclchg otheruser +rwx "#?" # enable r/w access to "otheruser" aclchg otheruser -x "#,at,aclchg,acladd,acldel,quit" # don't allow them to use these commands # ----- After doing this (once), you start your session with: $ screen Then, the other user can join your terminal session(s) with youruserid: $ screen -r youruserid/ Note: the trailing "/" is required. Multiple users can share the same screen simultaneously, each with independent access controlled precisely with "aclchg" in the ~/.screenrc file. I use the following setup: # ~/.screenrc-base # default screenrc on any host source $HOME/.screenrc-base source $HOME/.screenrc-$HOST source $HOME/.screenrc-users # ----- Then, the base configurations are in ~/.screenrc-base; the host-specific configurations are in ~/.screenrc-$HOST, and the user configurations are in ~/.screenrc-users. The host-specific .screenrc file might contain some host-specific screen commands; e.g.: # ~/.screen-myhost # ----- screen -t 'anywhere' /bin/tcsh screen -t 'anywhere1' /bin/tcsh # ---- The .screenrc-base contains: # ~/.screenrc-base ## I find typing ^a (Control-a) awkward. So I set the escape key to CTRL-j instead of a. escape ^Jj termcapinfo xterm* [email protected]:[email protected]: autodetach on zombie kr verbose on multiuser on

    % screen -r someuser/
    totoro · 2009-03-25 23:59:38 1
  • One person does `mkfifo foo; script -f foo' and another can supervise real-time what is being done using `cat foo'.

    mkfifo foo; script -f foo
    realist · 2011-09-08 02:51:44 5
  • I've been using linux for almost a decade and only recently discovered that most terminals like putty, xterm, xfree86, vt100, etc., support hundreds of shades of colors, backgrounds and text/terminal effects. This simply prints out a ton of them, the output is pretty amazing. If you use non-x terminals all the time like I do, it can really be helpful to know how to tweak colors and terminal capabilities. Like: echo $'\33[H\33[2J'

    for c in `seq 0 255`;do t=5;[[ $c -lt 108 ]]&&t=0;for i in `seq $t 5`;do echo -e "\e[0;48;$i;${c}m|| $i:$c `seq -s+0 $(($COLUMNS/2))|tr -d '[0-9]'`\e[0m";done;done
    AskApache · 2009-11-03 09:12:13 2
  • When some console full-screen program (minicom, vi, some installers) breaks down your terminal, try this command to revert all options to "sane" settings (sane is a built-in combo of a lot of stty options)

    stty sane
    darkpand · 2009-11-09 15:58:06 0
  • You can convert any UNIX man page to .txt

    man ls | col -b > ~/Desktop/man_ls.txt
    vigo · 2009-06-13 11:49:33 2
  • By default, screen tries to restore its old window sizes when attaching to resizable terminals. This command is the command-line equivalent to typing ^A F to fit an open screen session to the window.

    screen -raAd
    rkulla · 2010-04-12 22:54:58 1

  • 12
    <ctrl+z> bg
    lucafaus · 2010-10-26 18:07:54 0
  • Use GNU/screen as a terminal emulator for anything serial console related. screen /dev/tty eg. screen /dev/ttyS0 9600 MacOSX: Cheat Sheet: Show Sample Output

    screen /dev/tty<device> 9600
    px · 2010-07-20 09:12:13 3
  • Produces secure passwords that satisfy most rules for secure passwords and can be customized for correct output as needed. See "man pwgen" for details. Show Sample Output

    pwgen --alt-phonics --capitalize 9 10
    CafeNinja · 2009-10-24 08:36:36 11
  • After typing cd directory [enter] ls [enter] so many times, I figured I'd try to make it into a function. I was surprised how smoothly I was able to integrate it into my work on the command line. Just use cdls as you would cd. It will automatically list the directory contents after you cd into the directory. To make the command always available, add it to your .bashrc file. Not quite monumental, but still pretty convenient. Show Sample Output

    function cdls { cd $1; ls; }
    joem86 · 2009-03-10 19:13:47 6
  • This is super fast and an easy way to test your terminal for 256 color support. Unlike alot of info about changing colors in the terminal, this uses the ncurses termcap/terminfo database to determine the escape codes used to generate the colors for a specific TERM. That means you can switch your terminal and then run this to check the real output. tset xterm-256color at any rate that is some super lean code! Here it is in function form to stick in your .bash_profile aa_256 () { ( x=`tput op` y=`printf %$((${COLUMNS}-6))s`; for i in {0..256}; do o=00$i; echo -e ${o:${#o}-3:3} `tput setaf $i;tput setab $i`${y// /=}$x; done ) } From my bash_profile: Show Sample Output

    ( x=`tput op` y=`printf %$((${COLUMNS}-6))s`;for i in {0..256};do o=00$i;echo -e ${o:${#o}-3:3} `tput setaf $i;tput setab $i`${y// /=}$x;done; )
    AskApache · 2010-09-06 10:39:27 2

  • 7
    . ~/.bashrc
    xamaco · 2012-10-13 09:07:02 1
  • Any changes to BASH shell made in .bashrc will be active in the current terminal window from the moment you execute this command, ie. aliases, prompt settings etc. No need to restart terminal. (In BASH 'source' simile to 'eval' lets you generally execute any bunch of commands stacked in a text file).

    source ~/.bashrc
    knoppix5 · 2012-10-01 08:30:19 0

  • 4
    color () { local color=39; local bold=0; case $1 in green) color=32;; cyan) color=36;; blue) color=34;; gray) color=37;; darkgrey) color=30;; red) color=31;; esac; if [[ "$2" == "bold" ]]; then bold=1; fi; echo -en "\033[${bold};${color}m"; }
    zvyn · 2013-09-06 09:37:42 1
  • Simply sourcing .bashrc does not function correctly when you edit it and change an alias for a function or the other way round with the *same name*. I therefor use this function. Prior to re-sourcing .bashrc it unsets all aliases and functions.

    bashrc-reload() { builtin unalias -a; builtin unset -f $(builtin declare -F | sed 's/^.*declare[[:blank:]]\+-f[[:blank:]]\+//'); . ~/.bashrc; }
    Xk2c · 2014-03-02 14:24:18 1
  • One of my favorite ways to impress newbies (and old hats) to the power of the shell, is to give them an incredibly colorful and amazing version of the top command that runs once upon login, just like running fortune on login. It's pretty sweet believe me, just add this one-liner to your ~/.bash_profile -- and of course you can set the height to be anything, from 1 line to 1000! G=$(stty -g);stty rows $((${LINES:-50}/2));top -n1; stty $G;unset G Doesn't take more than the below toprc file I've added below, and you get all 4 top windows showing output at the same time.. each with a different color scheme, and each showing different info. Each window would normally take up 1/4th of your screen when run like that - TOP is designed as a full screen program. But here's where you might learn something new today on this great site.. By using the stty command to change the terminals internal understanding of the size of your terminal window, you force top to also think that way as well. # save the correct settings to G var. G=$(stty -g) # change the number of rows to half the actual amount, or 50 otherwise stty rows $((${LINES:-50}/2)) # run top non-interactively for 1 second, the output stays on the screen (half at least) top -n1 # reset the terminal back to the correct values, and clean up after yourself stty $G;unset G This trick from my [ bash_profile ], though the online version will be updated soon. Just think what else you could run like this! Note 1: I had to edit the toprc file out due to this site can't handle that (uploads/including code). So you can grab it from [ my site ] Note 2: I had to come back and edit again because the links weren't being correctly parsed Show Sample Output

    G=$(stty -g);stty rows $((${LINES:-50}/2));top -n1; stty $G;unset G
    AskApache · 2010-04-22 18:52:49 1
  • If you launch gnome-terminal manually, you can start with three open tabs

    gnome-terminal --tab --tab --tab
    0disse0 · 2009-09-03 19:36:07 0
  • This helps to keep track of what is going on when you have several tabs open in your terminal. The title automatically changes when you change directories.

    export PROMPT_COMMAND='echo -ne "\033]0;${PWD/#$HOME/~}\007";'
    dstahlke · 2009-09-23 16:38:06 0
  • One of the first functions programmers learn is how to print a line. This is my 100% bash builtin function to do it, which makes it as optimal as a function can be. The COLUMNS environment variable is also set by bash (including bash resetting its value when you resize your term) so its very efficient. I like pretty-output in my shells and have experimented with several ways to output a line the width of the screen using a minimal amount of code. This is like version 9,000 lol. This function is what I use, though when using colors or other terminal features I create separate functions that call this one, since this is the lowest level type of function. It might be better named printl(), but since I use it so much it's more optimal to have the name contain less chars (both for my programming and for the internal workings). If you do use terminal escapes this will reset to default. tput sgr0 For implementation ideas, check my Show Sample Output

    L(){ l=`builtin printf %${2:-$COLUMNS}s` && echo -e "${l// /${1:-=}}"; }
    AskApache · 2010-06-14 04:35:30 3
  • Continue a current job in the background and detach it from current terminal

    %1 &!
    Dema · 2011-01-14 02:26:24 1

  • 2
    bashrc-reload() { builtin exec bash ; }
    Xk2c · 2016-04-30 10:37:38 0
  • You may want to just use the shortcut "." instead of "source"

    . ~/.bashrc
    DNSpyder · 2012-10-01 08:41:19 0
  • Changes your group to the default group, has the same effect as sourcing your profile/rc file (in any shell) or logging out and back in again.

    newgrp -
    dendoes · 2012-10-01 10:23:56 1
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Rsync remote data as root using sudo
If your user has sudo on the remote box, you can rsync data as root without needing to login as root. This is very helpful if the remote box does not allow root to login over SSH (which is a common security restriction).

Get AWS temporary credentials ready to export based on a MFA virtual appliance
You might want to secure your AWS operations requiring to use a MFA token. But then to use API or tools, you need to pass credentials generated with a MFA token. This commands asks you for the MFA code and retrieves these credentials using AWS Cli. To print the exports, you can use: `awk '{ print "export AWS_ACCESS_KEY_ID=\"" $1 "\"\n" "export AWS_SECRET_ACCESS_KEY=\"" $2 "\"\n" "export AWS_SESSION_TOKEN=\"" $3 "\"" }'` You must adapt the command line to include: * $MFA_IDis ARN of the virtual MFA or serial number of the physical one * TTL for the credentials

Transfer large files/directories with no overhead over the network
This invokes tar on the remote machine and pipes the resulting tarfile over the network using ssh and is saved on the local machine. This is useful for making a one-off backup of a directory tree with zero storage overhead on the source. Variations on this include using compression on the source by using 'tar cfvp' or compression at the destination via $ ssh [email protected] "cd dir; tar cfp - *" | gzip - > file.tar.gz

watch your network load on specific network interface
-n means refresh frequency you could change eth0 to any interface you want, like wlan0

Get AWS temporary credentials ready to export based on a MFA virtual appliance
You might want to secure your AWS operations requiring to use a MFA token. But then to use API or tools, you need to pass credentials generated with a MFA token. This commands asks you for the MFA code and retrieves these credentials using AWS Cli. To print the exports, you can use: `awk '{ print "export AWS_ACCESS_KEY_ID=\"" $1 "\"\n" "export AWS_SECRET_ACCESS_KEY=\"" $2 "\"\n" "export AWS_SESSION_TOKEN=\"" $3 "\"" }'` You must adapt the command line to include: * $MFA_IDis ARN of the virtual MFA or serial number of the physical one * TTL for the credentials

Stop long commands wrapping around and over-writing itself in the Bash shell
add the command either in /etc/profile or ~/.bash_profile so that this is available to your shell.

check open ports without netstat or lsof

OpenDns IP update via curl
Your IP is resolved by OpenDns Server (like a caller ID telephone, every server knows who is calling ;-) Change user:password by yours Be Happy

Allow any local (non-network) connection to running X server

Rename files in batch

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