Commands tagged escape (6)

  • 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
  • Depending on the TERM, the terminfo version, ncurses version, etc.. you may be using a varied assortment of terminal escape codes. With this command you can easily find out exactly what is going on.. This is terminal escape zen! ( 2>&2 strace -f -F -e write -s 1000 sh -c 'echo -e "initc\nis2\ncnorm\nrmso\nsgr0" | tput -S' 2>&1 ) | grep -o '"\\[^"]*"' --color=always "\33]4;%p1%d;rgb:%p2%{255}%*%{1000}%/%2.2X/%p3%{255}%*%{1000}%/%2.2X/%p4%{255}%*%{1000}%/%2.2X\33\\\33[!p\33[?3;4l\33[4l\33>\33[?12l\33[?25h\33[27m\33(B\33[m" Lets say you want to find out what you need to echo in order to get the text to blink.. echo -e "`tput blink`This will blink`tput sgr0` This wont" Now you can use this function instead of calling tput (tput is much smarter for portable code because it works differently depending on the current TERM, and tput -T anyterm works too.) to turn that echo into a much faster executing code. tput queries files, opens files, etc.. but echo is very strait and narrow. So now you can do this: echo -e "\33[5mThis will blink\33(B\33[m This wont" More at Show Sample Output

    termtrace(){( strace -s 1000 -e write tput [email protected] 2>&2 2>&1 ) | grep -o '"[^"]*"';}
    AskApache · 2010-03-17 08:53:41 0
  • I was looking for the fastest way to create a bunch of ansi escapes for use in echo -e commands throughout a lot of my shell scripts. This is what I came up with, and I actually stick that loop command in a function and then just call that at the beginning of my scripts to not clutter the environment with these escape codes, which can wreck havok on my terminal when I'm dumping the environment. More of a cool way to store escape ansi codes in an array. You can echo them like: echo -e "${CC[15]}This text is black on bright green background." I usually just use with a function: # setup_colors - Adds colors to array CC for global use # 30 - Black, 31 - Red, 32 - Green, 33 - Yellow, 34 - Blue, 35 - Magenta, 36 - Blue/Green, 37 - White, 30/42 - Black on Green '30\;42' function setup_colors(){ declare -ax CC; for i in `seq 0 7`;do ii=$(($i+7));CC[$i]="\033[1;3${i}m";CC[$ii]="\033[0;3${i}m";done;CC[15]="\033[30;42m"; export R='\033[0;00m';export X="\033[1;37m"; }; export -f setup_colors CC[15] has a background of bright green which is why it is separate. R resets everything, and X is my default font of bright white. CC[15]="\033[30;42m"; R=$'\033[0;00m'; X=$'\033[1;37m' Those are just my favorite colors that I often use in my scripts. You can test which colors by running for i in $(seq 0 $((${#CC[@]} - 1))); do echo -e "${CC[$i]}[$i]\n$R"; done See: for more usage. Show Sample Output

    declare -ax CC; for i in `seq 0 7`;do ii=$(($i+7)); CC[$i]="\033[1;3${i}m"; CC[$ii]="\033[0;3${i}m"; done
    AskApache · 2009-09-21 07:00:55 4
  • Grabs the cmdline used to execute the process, and the environment that the process is being run under. This is much different than the 'env' command, which only lists the environment for the shell. This is very useful (to me at least) to debug various processes on my server. For example, this lets me see the environment that my apache, mysqld, bind, and other server processes have. Here's a function I use: aa_ps_all () { ( cd /proc && command ps -A -opid= | xargs -I'{}' sh -c 'test $PPID -ne {}&&test -r {}/cmdline&&echo -e "\n[{}]"&&tr -s "\000" " "<{}/cmdline&&echo&&tr -s "\000\033" "\nE"<{}/environ|sort&&cat {}/limits' ); } From my .bash_profile at Show Sample Output

    cd /proc&&ps a -opid=|xargs -I+ sh -c '[[ $PPID -ne + ]]&&echo -e "\n[+]"&&tr -s "\000" " "<+/cmdline&&echo&&tr -s "\000\033" "\nE"<+/environ|sort'
    AskApache · 2010-10-22 02:34:33 3
  • This is especially useful to get crazy stuff like space characters copied to your pasteboard correctly. Source: Show Sample Output

    perl -e "binmode(STDOUT, ':utf8'); print \"[email protected]\""; echo # newline
    mathias · 2012-01-02 10:34:51 0
  • Use if you want to include untrusted literal strings in your grep regexes. I use it to list all mounts below a directory: dir=/mnt/gentoo; cat /proc/mounts |awk '{print $2}' |egrep "^$(egrep_escape "$dir")(/|$)" /mnt/gentoo /mnt/gentoo/proc /mnt/gentoo/sys /mnt/gentoo/dev /mnt/gentoo/home Works even if $dir contains dangerous characters (e.g. comes from a commandline argument). Show Sample Output

    egrep_escape() { echo "$1" |sed -re 's/([\\.*+?(|)^$[])/\\\1/g' -e 's/\{/[{]/g'; }
    regnarg · 2012-08-02 16:54:43 0

What's this? is the place to record those command-line gems that you return to again and again. That way others can gain from your CLI wisdom and you from theirs too. All commands can be commented on, discussed and voted up or down.

Share Your Commands

Check These Out

Display Dilbert strip of the day
Requires display. Corrected version thanks to sputnick and eightmillion user.

save date and time for each command in history
for the change stay in your history file , export command by writing it into your .bashrc

Recursively remove directory with many files quickly
rsync'ing an empty directory over a directory to be deleted recursively is much faster than using rm -rf, for various reasons. Relevant only for directories with really a lot of files.

Find the package that installed a command

Email a file to yourself
This uses mutt to send the file, and doesn't require uuencode etc

Get an authorization code from Google
This is a basis for other Google API commands.

Process command output line by line in a while loop
This snippet allows to process the output of any bash command line by line.

get all bookmarks from all profiles from firefox
for i in $(ls /home/marco/.mozilla/firefox/*\.*/places.sqlite); do sqlite3 $i "SELECT strftime('%d.%m.%Y %H:%M:%S', dateAdded/1000000, 'unixepoch', 'localtime'),url FROM moz_places, moz_bookmarks WHERE = ORDER BY dateAdded;"; done

list block devices
Shows all block devices in a tree with descruptions of what they are.

Randomize lines in a file
Works in sort (GNU coreutils) 7.4, don't know when it was implemented but sometime the last 6 years.

Stay in the loop…

Follow the Tweets.

Every new command is wrapped in a tweet and posted to Twitter. Following the stream is a great way of staying abreast of the latest commands. For the more discerning, there are Twitter accounts for commands that get a minimum of 3 and 10 votes - that way only the great commands get tweeted.


Subscribe to the feeds.

Use your favourite RSS aggregator to stay in touch with the latest commands. There are feeds mirroring the 3 Twitter streams as well as for virtually every other subset (users, tags, functions,…):

Subscribe to the feed for: