All commands (14,187)

  • This is a handy way to circumvent the "Maximum line length of 2048 exceeded" grep error. Once you have run the above command (or put it in your .bashrc), files can be searched using: lgrep search-string /file/to/search


    1
    lgrep() { string=$1; file=$2; awk -v String=${string} '$0 ~ String' ${file}; }
    dopeman · 2010-01-19 09:42:19 3
  • To also move the db backup to another location you could pass the output to the dd command instead of a file mysqldump -u user -h host -ppwd -B dbname | bzip2 -zc9 | dd ssh usr@server "dd of=db_dump"


    1
    mysqldump -u user -h host -ppwd -B dbname | bzip2 -zc9 > dbname.sql.bz2
    olaseni · 2010-01-19 07:34:21 3

  • 1
    perl -i~ -0777pe's/^/\!\#\/usr\/bin\/ksh\n/' testing
    azil · 2010-01-19 06:49:10 4
  • This command defragment the SQLite databases found in the home folder of the current Windows user. This is usefull to speed up Firefox startup. The executable sqlite3.exe must be located in PATH or in the current folder. In a script use: for /f "delims==" %%a in (' dir "%USERPROFILE%\*.sqlite" /s/b ') do echo vacuum;|"sqlite3.exe" "%%a" Show Sample Output


    -3
    for /f "delims==" %a in (' dir "%USERPROFILE%\*.sqlite" /s/b ') do echo vacuum;|"sqlite3.exe" "%a"
    vutcovici · 2010-01-18 20:56:00 6
  • It's very common to have cron jobs that send emails as their output, but the From: address is whatever account the cron job is running under, which is often not the address you want replies to go to. Here's a way to change the From: address right on the command line. What's happening here is that the "--" separates the options to the mail client from options for the sendmail backend. So the -f and -F get passed through to sendmail and interpreted there. This works on even on a system where postfix is the active mailer - looks like postfix supports the same options. I think it's possible to customize the From: address using mutt as a command line mailer also, but most servers don't have mutt preinstalled.


    10
    mail -s "subject" user@todomain.com <emailbody.txt -- -f customfrom@fromdomain.com -F 'From Display Name'
    dmmst19 · 2010-01-18 19:55:27 30
  • if firefox is running the database is locked, so you need to copy the places.sqlite file temporarily somewhere to be able to query it...


    2
    sqlite3 -list /home/$USER/.mozilla/firefox/*.default/places.sqlite 'select url from moz_places ;' | grep http
    bubo · 2010-01-18 15:25:00 3
  • http://www.mplayerhq.hu/DOCS/HTML/en/menc-feat-mpeg.html MEncoder can create MPEG (MPEG-PS) format output files. Usually, when you are using MPEG-1 or MPEG-2 video, it is because you are encoding for a constrained format such as SVCD, VCD, or DVD. To change MEncoder's output file format, use the -of mpeg option. Creating an MPEG-1 file suitable to be played on systems with minimal multimedia support, such as default Windows installs: mencoder input.avi -of mpeg -mpegopts format=mpeg1:tsaf:muxrate=2000 \ -o output.mpg -oac lavc -lavcopts acodec=mp2:abitrate=224 -ovc lavc \ -lavcopts vcodec=mpeg1video:vbitrate=1152:keyint=15:mbd=2:aspect=4/3


    1
    mencoder input.avi -of mpeg -ovc lavc -lavcopts vcodec=mpeg1video \ -oac copy other_options -o output.mpg
    slishan · 2010-01-18 13:12:03 3
  • Also look at xload


    1
    tload -s 10
    chinmaya · 2010-01-18 08:14:06 3

  • 0
    purple-remote "setstatus?status=Available&message=Checking libpurple"
    spsneo · 2010-01-17 23:48:17 4
  • Note: you'll want to set up pub-key ssh auth. Gives you a quick means of changing volume/tracks/etc for rhythmbox on a remote machine. E.g.: rc --next # Play next track rc --print-playing # Grab the name rc --volume-down rc --help


    9
    alias rc='ssh ${MEDIAPCHOSTNAME} env DISPLAY=:0.0 rhythmbox-client --no-start'
    rhythmx · 2010-01-17 19:43:43 6

  • -1
    watch -n 7 -d 'uptime | sed s/.*users?, //'
    matthewbauer · 2010-01-17 18:45:52 3
  • cat - concatenate MP3 files and save it... Show Sample Output


    -4
    # cat file1.mp3 file2.mp3 > file3.mp3
    svnlabs · 2010-01-17 13:18:34 5
  • CHANGELOG Version 1.1 removedir () { echo "You are about to delete the current directory $PWD Are you sure?"; read human; if [[ "$human" = "yes" ]]; then blah=$(echo "$PWD" | sed 's/ /\\ /g'); foo=$(basename "$blah"); rm -Rf ../$foo/ && cd ..; else echo "I'm watching you" | pv -qL 10; fi; } BUG FIX: Folders with spaces Version 1.0 removedir () { echo "You are about to delete the current directory $PWD Are you sure?"; read human; if [[ "$human" = "yes" ]]; then blah=`basename $PWD`; rm -Rf ../$blah/ && cd ..; else echo "I'm watching you" | pv -qL 10; fi; } BUG FIX: Hidden directories (.dotdirectory) Version 0.9 rmdir () { echo "You are about to delete the current directory $PWD. Are you sure?"; read human; if [[ "$human" = "yes" ]]; then blah=`basename $PWD`; rm -Rf ../$blah/ && cd ..; else echo "I'm watching you" | pv -qL 10; fi; } Removes current directory with recursive and force flags plus basic human check. When prompted type yes 1. [user@host ~]$ ls foo bar 2. [user@host ~]$ cd foo 3. [user@host foo]$ removedir 4. yes 5. rm -Rf foo/ 6. [user@host ~]$ 7. [user@host ~]$ ls bar Show Sample Output


    -2
    removedir () { echo "Deleting the current directory $PWD Are you sure?"; read human; if [[ "$human" = "yes" ]]; then blah=$(echo "$PWD" | sed 's/ /\\ /g'); foo=$(basename "$blah"); rm -Rf ../$foo/ && cd ..; else echo "I'm watching you" | pv -qL 10; fi; }
    oshazard · 2010-01-17 11:34:38 31
  • Combines a few repetitive tasks when compiling source code. Especially useful when a hypen in a file-name breaks tab completion. 1.) wget source.tar.gz 2.) tar xzvf source.tar.gz 3.) cd source 4.) ls From there you can run ./configure, make and etc. Show Sample Output


    -1
    wtzc () { wget "$@"; foo=`echo "$@" | sed 's:.*/::'`; tar xzvf $foo; blah=`echo $foo | sed 's:,*/::'`; bar=`echo $blah | sed -e 's/\(.*\)\..*/\1/' -e 's/\(.*\)\..*/\1/'`; cd $bar; ls; }
    oshazard · 2010-01-17 11:25:47 3

  • 2
    echo -e "swap=me\n1=2"|sed 's/\(.*\)=\(.*\)/\2=\1/g'
    axelabs · 2010-01-16 22:01:37 3
  • Will find all files containing "sample" in the current directory and in the directories below.


    -9
    find . -exec grep -l "sample" {} \;
    whoami · 2010-01-16 13:12:52 4

  • 6
    mwiki () { blah=`echo $@ | sed -e 's/ /_/g'`; dig +short txt $blah.wp.dg.cx; }
    oshazard · 2010-01-16 07:13:43 3
  • This is very similar to the first example except that it employs the 'exec' argument of the find command rather than piping the result to xargs. The second example is nice and tidy but different *NIXs may not have as capable a grep command.


    -1
    find . -name "*.php" -exec grep -il searchphrase {} \;
    unixmonkey7797 · 2010-01-16 05:09:30 4
  • I use this command (PS1) to show a list bash prompt's special characters. I tested it against A flavor of Red Hat Linux and Mac OS X Show Sample Output


    3
    alias PS1="man bash | sed -n '/ASCII bell/,/end a sequence/p'"
    haivu · 2010-01-15 23:39:28 3

  • -2
    hdid somefile.dmg
    rnoyfb · 2010-01-15 12:00:48 5
  • If you really _must_ use a loop, this is better than parsing the output of 'ps': PID=$! ;while kill -0 $PID &>/dev/null; do sleep 1; done kill -0 $PID returns 0 if the process still exists; otherwise 1


    0
    wait
    bhepple · 2010-01-15 04:03:11 5

  • -4
    dd if=/dev/zero of=/tmp/bigfile bs=1024k count=100
    wincus · 2010-01-15 00:44:44 4
  • shorter :p Show Sample Output


    2
    grep -rHi searchphrase *.php
    psybermonkey · 2010-01-15 00:23:25 5
  • This command will find all files recursively containing the phrase entered, represented here by "searchphrase". This particular command searches in all php files, but you could change that to just be html files or just log files etc. Show Sample Output


    2
    find . -name "*.php" | xargs grep -il searchphrase
    refrax · 2010-01-14 22:42:36 5
  • This will output the characters at 10 per second.


    124
    echo "You can simulate on-screen typing just like in the movies" | pv -qL 10
    dennisw · 2010-01-14 20:17:44 880
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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"

cpuinfo

Advanced python tracing
Trace python statement execution and syscalls invoked during that simultaneously

floating point operations in shell scripts
allows you to use floating point operations in shell scripts

Given process ID print its environment variables
Same as previous but without fugly sed =x

Double your disk read performance in a single command
(WARN) This will absolutely not work on all systems, unless you're running large, high speed, hardware RAID arrays. For example, systems using Dell PERC 5/i SAS/SATA arrays. If you have a hardware RAID array, try it. It certainly wont hurt. You may be can test the speed disk with some large file in your system, before and after using this: $ time dd if=/tmp/disk.iso of=/dev/null bs=256k To know the value of block device parameter known as readahead. $ blockdev --getra /dev/sdb And set the a value 1024, 2048, 4096, 8192, and maybe 16384... it really depends on the number of hard disks, their speed, your RAID controller, etc. (see sample)

Shell function to create a menu of items which may be inserted into the X paste buffer.
The function will take a comma separated list of items to be 'selected' by xsel -i: $ smenu "First item to paste,Paste me #2,Third menu item" You will then be prompted to choose one of the menu items. After you choose, you will be able to paste the string by clicking the middle mouse button. The menu will keep prompting you to choose menu items until you break out with Control-C.

Make changes in any profile available immediately/Change to default group
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.

FAST Search and Replace for Strings in all Files in Directory
I needed a way to search all files in a web directory that contained a certain string, and replace that string with another string. In the example, I am searching for "askapache" and replacing that string with "htaccess". I wanted this to happen as a cron job, and it was important that this happened as fast as possible while at the same time not hogging the CPU since the machine is a server. So this script uses the nice command to run the sh shell with the command, which makes the whole thing run with priority 19, meaning it won't hog CPU processing. And the -P5 option to the xargs command means it will run 5 separate grep and sed processes simultaneously, so this is much much faster than running a single grep or sed. You may want to do -P0 which is unlimited if you aren't worried about too many processes or if you don't have to deal with process killers in the bg. Also, the -m1 command to grep means stop grepping this file for matches after the first match, which also saves time.

exit if another instance is running


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