Commands by dopeman (11)

  • The command (above) will remove any duplicate rows based on the FIRST column of data in an un-sorted file. The '$1' represents a positional parameter. You can change both instances of '$1' in the command to remove duplicates based on a different column, for instance, the third: awk '{ if ($3 in stored_lines) x=1; else print; stored_lines[$3]=1 }' infile.txt > outfile.txt Or you can change it to '$0' to base the removal on the whole row: awk '{ if ($0 in stored_lines) x=1; else print; stored_lines[$0]=1 }' infile.txt > outfile.txt ** Note: I wouldn't use this on a MASSIVE file, unless you're RAM-rich ;) **


    4
    awk '{ if ($1 in stored_lines) x=1; else print; stored_lines[$1]=1 }' infile.txt > outfile.txt
    dopeman · 2010-12-15 17:08:47 0
  • buf myfile.txt This is useful when you are making small but frequent changes to a file. It keeps things organised and clear for another administrator to see what changed and at what time. An overview of changes can be deduced using a simple: ls -ltr


    1
    buf () { filename=$1; filetime=$(date +%Y%m%d_%H%M%S); cp ${filename} ${filename}_${filetime}; }
    dopeman · 2010-12-14 13:19:52 2
  • Essentially the same as funky's alias, but will not traverse filesystems and has nicer formatting. Show Sample Output


    -1
    alias dush="du -xsm * | sort -n | awk '{ printf(\"%4s MB ./\",\$1) ; for (i=1;i<=NF;i++) { if (i>1) printf(\"%s \",\$i) } ; printf(\"\n\") }' | tail"
    dopeman · 2010-07-15 10:38:27 1
  • I have come across a situation in the past where someone has unlinked a file by running an 'rm' command against it while it was still being written to by a running process. The problem manifested itself when a 'df' command showed a filesystem at 100%, but this did not match the total value of a 'du -sk *'. When this happens, the process continues to write to the file but you can no longer see the file on the filesystem. Stopping and starting the process will, more often than not, get rid of the unlinked file, however this is not always possible on a live server. When you are in this situation you can use the 'lsof' command above to get the PID of the process that owns the file (in the sample output this is 23521). Run the following command to see a sym-link to the file (marked as deleted): cd /proc/23521/fd && ls -l Truncate the sym-link to regain your disk space: > /proc/23521/fd/3 I should point out that this is pretty brutal and *could* potentially destabilise your system depending on what process the file belongs to that you are truncating. Show Sample Output


    16
    lsof +L1
    dopeman · 2010-07-14 17:21:01 2
  • 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 0
  • This does the same thing as many of the 'grep' based alternatives but allows a more finite control over the output. For example if you only wanted the process ID you could change the command: ps -ef | awk '/mingetty/ && !/awk/ {print $2}' If you wanted to kill the returned PID's: ps -ef | awk '/mingetty/ && !/awk/ {print $2}' | xargs -i kill {} Show Sample Output


    1
    ps -ef | awk '/process-name/ && !/awk/ {print}'
    dopeman · 2009-08-19 11:22:09 0
  • This command will copy files and directories from a remote machine to the local one. Ensure you are in the local directory you want to populate with the remote files before running the command. To copy a directory and it's contents, you could: ssh [email protected] "(cd /path/to/a/directory ; tar cvf - ./targetdir)" | tar xvf - This is especially useful on *nix'es that don't have 'scp' installed by default.


    1
    ssh [email protected] "(cd /path/to/remote/top/dir ; tar cvf - ./*)" | tar xvf -
    dopeman · 2009-03-31 13:08:45 3
  • This command will show the 20 processes using the most CPU time (hungriest at the bottom). You can see the 20 most memory intensive processes (hungriest at the bottom) by running: ps aux | sort +3n | tail -20 Or, run both: echo "CPU:" && ps aux | sort +2n | tail -20 && echo "Memory:" && ps aux | sort +3n | tail -20


    3
    ps aux | sort +2n | tail -20
    dopeman · 2009-03-31 12:03:34 1
  • This command will tell you the 20 biggest directories starting from your working directory and skips directories on other filesystems. Useful for resolving disk space issues.


    7
    du -xk | sort -n | tail -20
    dopeman · 2009-03-30 11:37:43 3
  • This command will replace all instances of 'foo' with 'bar' in all files in the current working directory and any sub-directories.


    -1
    perl -pi -e 's/foo/bar/g' $(grep -rl foo ./*)
    dopeman · 2009-03-27 17:21:35 2
  • This command will replace all instances of 'foo' with 'bar' in all files in the current working directory.


    -1
    perl -pi -e 's/foo/bar/g' $(grep -l foo ./*)
    dopeman · 2009-03-27 17:18:08 1

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Show directories in the PATH, one per line
Shorter version.

Show the UUID of a filesystem or partition
Show the UUID-based alternate device names of ZEVO-related partitions on Darwin/OS X. Adapted from the lines by dbrady at http://zevo.getgreenbytes.com/forum/viewtopic.php?p=700#p700 and following the disk device naming scheme at http://zevo.getgreenbytes.com/wiki/pmwiki.php?n=Site.DiskDeviceNames

Display the history and optionally grep
Place this in your .bash_profile and you can use it two different ways. If you issue 'h' on its own, then it acts like the history command. If you issue: $ h cd Then it will display all the history with the word 'cd'

check open ports without netstat or lsof

Console clock
Shows a simple clock in the console -t param removes the watch header Ctrl-c to exit

fast access to any of your favorite directory.
example: -------------------------------------------------------------------------------------------- [email protected]:~/workspace/SVN/haystak-repos/trunk/internal/src$ addpi -------------------------------------------------------------------------------------------- Now that directory is in the list of fast access directories. You can switch to it anytime like this: -------------------------------------------------------------------------------------------- [email protected]:~$ pi internal` [email protected]:~/workspace/SVN/haystak-repos/trunk/internal/src$ -------------------------------------------------------------------------------------------- Please note the backquote ( the symbol that shares its key with ~ in the keyboard ) pi will switch you to that directory. To see the list of all fast access directories you have to say "cat ~/.pi"

Convert seconds to [DD:][HH:]MM:SS
Converts any number of seconds into days, hours, minutes and seconds. sec2dhms() { declare -i SS="$1" D=$(( SS / 86400 )) H=$(( SS % 86400 / 3600 )) M=$(( SS % 3600 / 60 )) S=$(( SS % 60 )) [ "$D" -gt 0 ] && echo -n "${D}:" [ "$H" -gt 0 ] && printf "%02g:" "$H" printf "%02g:%02g\n" "$M" "$S" }

What is my public IP address
Clean output, if used in scripts: $ GET checkip.dyndns.org|grep -o '[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}' or $ GET icanhazip.com

Change display resolution
-s must be a valid resolution. You can get a list of valid (and supported) resolutions via `xrandr`.

Show log message including which files changed for a given commit in git.


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