Commands tagged bash (805)

  • Example : vim /etc/fstab ## damn <ctrl+u> sudo <ctrl+y> ## like a boss. Example 2 : sudo vim /root/bin/ ##uh... autocomplete doesn't work... <ctrl+u> sudo ls /root/bin ##ah! that's the name of the file! <ctrl+y> sudo vim /root/bin/ ##resume here! Thanks readline!


    211
    <ctrl+u> [...] <ctrl+y>
    adeverteuil · 2010-07-23 03:33:46 7

  • 137
    disown -a && exit
    prayer · 2009-04-10 12:22:34 8
  • When using reverse-i-search you have to type some part of the command that you want to retrieve. However, if the command is very complex it might be difficult to recall the parts that will uniquely identify this command. Using the above trick it's possible to label your commands and access them easily by pressing ^R and typing the label (should be short and descriptive). UPDATE: One might suggest using aliases. But in that case it would be difficult to change some parts of the command (such as options, file/directory names, etc).


    97
    some_very_long_and_complex_command # label
    jamolkhon · 2009-09-08 05:58:27 14

  • 92
    lsof -P -i -n
    OJM · 2009-09-19 18:28:48 1
  • CDPATH tells the cd command to look in this colon-separated list of directories for your destination. My preferred order are 1) the current directory, specified by the empty string between the = and the first colon, 2) the parent directory (so that I can cd lib instead of cd ../lib), 3) my home directory, and 4) my ~/projects directory.


    86
    CDPATH=:..:~:~/projects
    haivu · 2009-03-20 14:50:25 8
  • /usr/sbin/ab2 -f TLS1 -S -n 1000 -c 100 -t 2 http://www.google.com/ then !:- http://www.commandlinefu.com/ is the same as /usr/sbin/ab2 -f TLS1 -S -n 1000 -c 100 -t 2 http://www.commandlinefu.com/


    73
    !:-
    new_user · 2010-05-15 15:12:47 1
  • defines a handy function for quick calculations from cli. once defined: ? 10*2+3 Show Sample Output


    58
    ? () { echo "$*" | bc -l; }
    fizz · 2009-06-28 20:15:30 14
  • This is the result of a several week venture without X. I found myself totally happy without X (and by extension without flash) and was able to do just about anything but watch YouTube videos... so this a the solution I came up with for that. I am sure this can be done better but this does indeed work... and tends to work far better than YouTube's ghetto proprietary flash player ;-) Replace $i with any YouTube ID you want and this will scrape the site for the _real_ URL to the full quality .FLV file on Youtube's server and will then will hand that over to mplayer (or vlc or whatever you want) to be streamed. In some browsers you can replace $i with just a % or put this in a shell script so all YouTube IDs can be handed directly off to your media player of choice for true streaming without the need for Flash or a downloader like clive. (I do however fully recommend clive if you wish to archive videos instead of streaming them) If any interest is shown I would be more than happy to provide similar commands for other sites. Most streaming flash players use similar logic to YouTube. Edit: 05/03/2011 - Updated line to work with current YouTube. It could be a lot prettier but I will probably follow up with another update when I figure out how to get rid of that pesky Grep. Sed should take that syntax... but it doesn't. Original (no longer working) command: mplayer -fs $(echo "http://youtube.com/get_video.php?$(curl -s $youtube_url | sed -n "/watch_fullscreen/s;.*\(video_id.\+\)&title.*;\1;p")") Show Sample Output


    57
    i="8uyxVmdaJ-w";mplayer -fs $(curl -s "http://www.youtube.com/get_video_info?&video_id=$i" | echo -e $(sed 's/%/\\x/g;s/.*\(v[0-9]\.lscache.*\)/http:\/\/\1/g') | grep -oP '^[^|,]*')
    lrvick · 2009-03-09 03:57:44 15
  • The biggest advantage of this over the functions is that it is portable.


    55
    mkdir /home/foo/doc/bar && cd $_
    kzh · 2011-08-12 11:29:19 0
  • This version uses read instead of eval.


    54
    read day month year <<< $(date +'%d %m %y')
    putnamhill · 2011-07-29 15:05:19 4
  • You're running a script, command, whatever.. You don't expect it to take long, now 5pm has rolled around and you're ready to go home... Wait, it's still running... You forgot to nohup it before running it... Suspend it, send it to the background, then disown it... The ouput wont go anywhere, but at least the command will still run... Show Sample Output


    53
    ^Z $bg $disown
    fall0ut · 2009-03-17 21:52:52 13
  • for one line per process: ss -p | cat for established sockets only: ss -p | grep STA for just process names: ss -p | cut -f2 -sd\" or ss -p | grep STA | cut -f2 -d\"


    52
    ss -p
    Escher · 2009-09-19 21:55:01 0
  • This is how I typically grep. -R recurse into subdirectories, -n show line numbers of matches, -i ignore case, -s suppress "doesn't exist" and "can't read" messages, -I ignore binary files (technically, process them as having no matches, important for showing inverted results with -v) I have grep aliased to "grep --color=auto" as well, but that's a matter of formatting not function.


    49
    grep -RnisI <pattern> *
    birnam · 2009-09-22 15:09:43 3
  • Same as http://www.commandlinefu.com/commands/view/5876, but for bash. This will show a numerical value for each of the 256 colors in bash. Everything in the command is a bash builtin, so it should run on any platform where bash is installed. Prints one color per line. If someone is interested in formatting the output, paste the alternative.


    47
    for code in {0..255}; do echo -e "\e[38;05;${code}m $code: Test"; done
    scribe · 2010-06-19 02:14:42 4
  • This command shows the various shortcuts that can be use in bash, including Ctrl+L, Ctrl+R, etc... You can translate "\C-y" to Ctrl+y, for example. Show Sample Output


    40
    bind -P
    ricardofunke · 2012-05-28 18:51:59 3
  • This uses Bash's "process substitution" feature to compare (using diff) the output of two different process pipelines.


    35
    diff <(cd dir1 && find | sort) <(cd dir2 && find | sort)
    mbirk · 2009-05-21 04:44:29 7
  • show only the name of the apps that are using internet Show Sample Output


    34
    lsof -P -i -n | cut -f 1 -d " "| uniq | tail -n +2
    edo · 2009-09-19 21:23:54 2
  • How often do you make a directory (or series of directories) and then change into it to do whatever? 99% of the time that is what I do. This BASH function 'md' will make the directory path then immediately change to the new directory. By using the 'mkdir -p' switch, the intermediate directories are created as well if they do not exist. Show Sample Output


    31
    md () { mkdir -p "$@" && cd "$@"; }
    drewk · 2009-09-24 16:09:19 5
  • If you're a moron like me, sometimes your fingers get away from you and you, for example, enter your password when you're already authenticated to ssh-agent, sudo, etc., and your password ends up in shell history. Here's how to get it out. Show Sample Output


    30
    history -d
    sud0er · 2009-04-27 20:19:09 3
  • sorts the files by integer megabytes, which should be enough to (interactively) find the space wasters. Now you can dush for the above output, dush -n 3 for only the 3 biggest files and so on. It's always a good idea to have this line in your .profile or .bashrc Show Sample Output


    29
    alias dush="du -sm *|sort -n|tail"
    funky · 2010-03-26 10:18:57 1
  • Run the alias command, then issue ps aux | head and resize your terminal window (putty/console/hyperterm/xterm/etc) then issue the same command and you'll understand. ${LINES:-`tput lines 2>/dev/null||echo -n 12`} Insructs the shell that if LINES is not set or null to use the output from `tput lines` ( ncurses based terminal access ) to get the number of lines in your terminal. But furthermore, in case that doesn't work either, it will default to using the deafault of 12 (-2 = 10). The default for HEAD is to output the first 10 lines, this alias changes the default to output the first x lines instead, where x is the number of lines currently displayed on your terminal - 2. The -2 is there so that the top line displayed is the command you ran that used HEAD, ie the prompt. Depending on whether your PS1 and/or PROMPT_COMMAND output more than 1 line (mine is 3) you will want to increase from -2. So with my prompt being the following, I need -7, or - 5 if I only want to display the commandline at the top. ( http://www.askapache.com/linux-unix/bash-power-prompt.html ) 275MB/748MB [7995:7993 - 0:186] 06:26:49 Thu Apr 08 [askapache@n1-backbone5:/dev/pts/0 +1] ~ In most shells the LINES variable is created automatically at login and updated when the terminal is resized (28 linux, 23/20 others for SIGWINCH) to contain the number of vertical lines that can fit in your terminal window. Because the alias doesn't hard-code the current LINES but relys on the $LINES variable, this is a dynamic alias that will always work on a tty device. Show Sample Output


    26
    alias head='head -n $((${LINES:-`tput lines 2>/dev/null||echo -n 12`} - 2))'
    AskApache · 2010-04-08 22:37:06 7
  • Uses the last argument of the last executed command, and gets the directory name from it. Use $!:t for the filename alone, without the dirname. Show Sample Output


    25
    cd !$:h
    lingo · 2009-08-07 00:37:08 2
  • You can use [n]> combined with >(cmd) to attach the various output file descriptors to be the input of different commands.


    25
    some_command > >(/bin/cmd_for_stdout) 2> >(/bin/cmd_for_stderr)
    tylerl · 2009-12-01 03:58:04 0
  • Add this to a fiend's .bashrc. PROMPT_COMMAND will run just before a prompt is drawn. RANDOM will be between 0 and 32768; in this case, it'll run about 1/10th of the time. \033 is the escape character. I'll call it \e for short. \e7 -- save cursor position. \e[%d;%dH -- move cursor to absolute position \e[4%dm \e[m -- draw a random color at that point \e8 -- restore position.


    25
    PROMPT_COMMAND='if [ $RANDOM -le 3200 ]; then printf "\0337\033[%d;%dH\033[4%dm \033[m\0338" $((RANDOM%LINES+1)) $((RANDOM%COLUMNS+1)) $((RANDOM%8)); fi'
    hotdog003 · 2010-04-01 06:52:32 3
  • I save this to bin/iptrace and run "iptrace ipaddress" to get the Country, City and State of an ip address using the http://ipadress.com service. I add the following to my script to get a tinyurl of the map as well: URL=`lynx -dump http://www.ip-adress.com/ip_tracer/?QRY=$1|grep details|awk '{print $2}'` lynx -dump http://tinyurl.com/create.php?url=$URL|grep tinyurl|grep "19. http"|awk '{print $2}'


    24
    lynx -dump http://www.ip-adress.com/ip_tracer/?QRY=$1|grep address|egrep 'city|state|country'|awk '{print $3,$4,$5,$6,$7,$8}'|sed 's\ip address flag \\'|sed 's\My\\'
    leftyfb · 2009-02-25 17:16:56 5
  •  1 2 3 >  Last ›

What's this?

commandlinefu.com 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

Count opening and closing braces in a string.
This function counts the opening and closing braces in a string. This is useful if you have eg long boolean expressions with many braces and you simply want to check if you didn't forget to close one.

Which processes are listening on a specific port (e.g. port 80)
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

Exclude a string with awk

Finding all files on local file system with SUID and SGID set

Set laptop display brightness
Run as root. Path may vary depending on laptop model and video card (this was tested on an Acer laptop with ATI HD3200 video). $ cat /proc/acpi/video/VGA/LCD/brightness to discover the possible values for your display.

convert wmv into xvid avi format

Display the top 10 running processes - sorted by memory usage
A pretty nice display of processes.

GREP a PDF file.
PDF files are simultaneously wonderful and heinous. They are wonderful in being ubiquitous and mostly being cross platform. They are heinous in being very difficult to work with from the command line, search, grep, use only the text inside the PDF, or use outside of proprietary products. xpdf is a wonderful set of PDF tools. It is on many linux distros and can be installed on OS X. While primarily an open PDF viewer for X, xpdf has the tool "pdftotext" that can extract formated or unformatted text from inside a PDF that has text. This text stream can then be further processed by grep or other tool. The '-' after the file name directs output to stdout rather than to a text file the same name as the PDF. Make sure you use version 3.02 of pdftotext or later; earlier versions clipped lines. The lines extracted from a PDF without the "-layout" option are very long. More paragraphs. Use just to test that a pattern exists in the file. With "-layout" the output resembles the lines, but it is not perfect. xpdf is available open source at http://www.foolabs.com/xpdf/

Find the package that installed a command

FizzBuzz in one line of Bash
The (in)famous "FizzBuzz" programming challenge, answered in a single line of Bash code. The "|column" part at the end merely formats the output a bit, so if "column" is not installed on your machine you can simply omit that part. Without "|column", the solution only uses 75 characters. The version below is expanded to multiple lines, with comments added. for i in {1..100} # Use i to loop from "1" to "100", inclusive. do ((i % 3)) && # If i is not divisible by 3... x= || # ...blank out x (yes, "x= " does that). Otherwise,... x=Fizz # ...set x to the string "Fizz". ((i % 5)) || # If i is not divisible by 5, skip (there's no "&&")... x+=Buzz # ...Otherwise, append (not set) the string "Buzz" to x. echo ${x:-$i} # Print x unless it is blanked out. Otherwise, print i. done | column # Wrap output into columns (not part of the test).


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.

» http://twitter.com/commandlinefu
» http://twitter.com/commandlinefu3
» http://twitter.com/commandlinefu10

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: