Commands by lig0n (2)

  • Scrap everything and use `gawk` to do all the magic, since it's like the future or something. gawk 'match($11, /[a-z]{3}$/) && match($9, /^ata-/) { gsub("../", ""); print $11,"\t",$9 }' Yank out only ata- lines that have a drive letter (ignore lines with partitions). Then strip ../../ and print the output. Yay awk. Be sure to see the alternatives as my initial command is listed there. This one is a revision of the original. Show Sample Output


    2
    ls -l /dev/disk/by-id |gawk 'match($11, /[a-z]{3}$/) && match($9, /^ata-/) { gsub("../", ""); print $11,"\t",$9 }' |sort
    lig0n · 2015-05-18 15:42:33 1
  • This is much easier to parse and do something else with (eg: automagically create ZFS vols) than anything else I've found. It also helps me keep track of which disks are which, for example, when I want to replace a disk, or image headers in different scenarios. Being able to match a disk to the kernels mapping of said drive the disks serial number is very helpful ls -l /dev/disk/by-id Normal `ls` command to list contents of /dev/disk/by-id grep -v "wwn-" Perform an inverse search - that is, only output non-matches to the pattern 'wwn-' egrep "[a-zA-Z]{3}$" A regex grep, looking for three letters and the end of a line (to filter out fluff) sed 's/\.\.\/\.\.\///' Utilize sed (stream editor) to remove all occurrences of "../../" sed -E 's/.*[0-9]{2}:[0-9]{2}\s//' Strip out all user and permission fluff. The -E option lets us use extended (modern) regex notation (larger control set) sed -E 's/->\ //' Strip out ascii arrows "-> " sort -k2 Sort the resulting information alphabetically, on column 2 (the disk letters) awk '{print $2,$1}' Swap the order of the columns so it's easier to read/utilize output from sed 's/\s/\t/' Replace the space between the two columns with a tab character, making the output more friendly For large ZFS pools, this made creating my vdevs immeasurably easy. By keeping track of which disks were in which slot (spreadsheet) via their serial numbers, I was able to then create my vols simply by copying and pasting the full output of the disk (not the letter) and pasting it into my command. Thereby allowing me to know exactly which disk, in which slot, was going into the vdev. Example command below. zpool create tank raidz2 -o ashift=12 ata-... ata-... ata-... ata-... ata-... ata-... Show Sample Output


    0
    ls -l /dev/disk/by-id |grep -v "wwn-" |egrep "[a-zA-Z]{3}$" |sed 's/\.\.\/\.\.\///' |sed -E 's/.*[0-9]{2}:[0-9]{2}\s//' |sed -E 's/->\ //' |sort -k2 |awk '{print $2,$1}' |sed 's/\s/\t/'
    lig0n · 2015-01-25 19:29:40 0

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GZip all files in a directory separately

Write comments to your history.
A null operation with the name 'comment', allowing comments to be written to HISTFILE. Prepending '#' to a command will *not* write the command to the history file, although it will be available for the current session, thus '#' is not useful for keeping track of comments past the current session.

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" }

See how many more processes are allowed, awesome!
There is a limit to how many processes you can run at the same time for each user, especially with web hosts. If the maximum # of processes for your user is 200, then the following sets OPTIMUM_P to 100. $ OPTIMUM_P=$(( (`ulimit -u` - `find /proc -maxdepth 1 \( -user $USER -o -group $GROUPNAME \) -type d|wc -l`) / 2 )) This is very useful in scripts because this is such a fast low-resource-intensive (compared to ps, who, lsof, etc) way to determine how many processes are currently running for whichever user. The number of currently running processes is subtracted from the high limit setup for the account (see limits.conf, pam, initscript). An easy to understand example- this searches the current directory for shell scripts, and runs up to 100 'file' commands at the same time, greatly speeding up the command. $ find . -type f | xargs -P $OPTIMUM_P -iFNAME file FNAME | sed -n '/shell script text/p' I am using it in my http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html especially for the xargs command. Xargs has a -P option that lets you specify how many processes to run at the same time. For instance if you have 1000 urls in a text file and wanted to download all of them fast with curl, you could download 100 at a time (check ps output on a separate [pt]ty for proof) like this: $ cat url-list.txt | xargs -I '{}' -P $OPTIMUM_P curl -O '{}' I like to do things as fast as possible on my servers. I have several types of servers and hosting environments, some with very restrictive jail shells with 20processes limit, some with 200, some with 8000, so for the jailed shells my xargs -P10 would kill my shell or dump core. Using the above I can set the -P value dynamically, so xargs always works, like this. $ cat url-list.txt | xargs -I '{}' -P $OPTIMUM_P curl -O '{}' If you were building a process-killer (very common for cheap hosting) this would also be handy. Note that if you are only allowed 20 or so processes, you should just use -P1 with xargs.

Get My Public IP Address

Find usb device
I often use it to find recently added ou removed device, or using find in /dev, or anything similar. Just run the command, plug the device, and wait to see him and only him

List the size (in human readable form) of all sub folders from the current location
Tested on MacOS and GNU/Linux. It works in dirs containing files starting with '-'. It runs 'du' only once. It sorts according to size. It treats 1K=1000 (and not 1024)

Sort a character string
Sorts a character string, using common shell commands.

list files recursively by size

Run CPU benchmark from command line
Run CPU benchmark from command line


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