Commands by zlemini

Commands by zlemini (44)

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Find all files larger than 500M and less than 1GB
This is sample output - yours may be different.
10

find / -type f -size +500M -size -1G

zlemini · 2011-11-22 19:43:05 5
Target a specific column for pattern substitution

Awk replaces every instance of foo with bar in the 5th column only.
This is sample output - yours may be different.
12

awk '{gsub("foo","bar",$5)}1' file

zlemini · 2011-11-09 18:24:23 7
Exclude multiple columns using AWK

Print all columns except the 1st and 3rd.
This is sample output - yours may be different.
31

awk '{$1=$3=""}1' file

zlemini · 2011-10-25 22:15:06 17
background a wget download
This is sample output - yours may be different.
6

wget -b http://dl.google.com/android/android-sdk_r14-linux.tgz

zlemini · 2011-10-19 21:55:25 6
View files opened by a program on startup and shutdown

Run this before you run a command in order to see what the command does as it starts. The -c flag is useful here as the PID is unknown before startup. All config files, libraries, logs, ports, etc used by the command as it starts up, (and shuts down) will be captured at 1s intervals and written to a file. Useful for debugging etc. Show Sample Output
This is sample output - yours may be different.
```
sudo lsof -rc httpd >> /tmp/FILE
```
6

sudo lsof -rc command >> /tmp/command.txt

zlemini · 2011-08-03 20:19:53 6
View internet connection activity in a browser

The output of lsof is piped to txt2html which converts it to html. # Perl module HTML::TextToHTML needed Show Sample Output
This is sample output - yours may be different.
```
Open html file with browser to view output.
```
2

lsof -nPi | txt2html > ~/lsof.html

zlemini · 2011-07-28 14:01:21 9
View any already in progress copy command in detail

If you spot a dubious looking cp command running you can use this command to view what is being copied and to where. 1234 is the PID of the cp command being passed to the lsof utility. 3r.*REG will display the file/directory that is being read/copied. 4w.*REG will display the destination it is being written to.
This is sample output - yours may be different.
2

sudo lsof -p1234 | grep -E "(3r|4w).*REG"

zlemini · 2011-01-11 19:45:24 6
exclude a column with awk

Here's an awk alternative, for those lacking the version of cut with the --complement argument.
This is sample output - yours may be different.
11

awk '{ $5=""; print }' file

zlemini · 2010-10-22 09:48:49 4
View details of network activity, malicious or otherwise within a port range.

View details of both TCP and UDP network activity within a specified port range. Show Sample Output
This is sample output - yours may be different.
```
COMMAND    PID           USER   FD   TYPE    DEVICE SIZE/OFF NODE NAME
```
5

lsof -i :555-7000

zlemini · 2010-10-07 20:45:54 5
View user activity per directory.

View all files opened by a user in specified directory. The +D option makes lsof search all sub-directories to complete depth, while ignoring symbolic links.
This is sample output - yours may be different.
16

sudo lsof -u someuser -a +D /etc

zlemini · 2010-06-11 06:37:27 7
Tail a log-file over the network

Netcat is used to serve a log-file over a network on port 1234. Point a browser to the specified server/port combo to view log-file updates in real-time.
This is sample output - yours may be different.
4

tail -f error_log | nc -l 1234

zlemini · 2010-05-07 18:14:04 9
Quickly analyse an Apache error log

This searches the Apache error_log for each of the 5 most significant Apache error levels, if any are found the date is then cut from the output in order to sort then print the most common occurrence of each error. Show Sample Output
This is sample output - yours may be different.
```
  4  [emerg] (17)File exists: Couldn't create accept lock 
  20 [error] [client 1.2.3.4] File does not exist: /Welcome, referer: http://127.0.0.1/
  23 [warn] Init: Session Cache is not configured [hint: SSLSessionCache]
```
4

for i in emerg alert crit error warn ; do awk '$6 ~ /^\['$i'/ {print substr($0, index($0,$6)) }' error_log | sort | uniq -c | sort -n | tail -1; done

zlemini · 2010-04-15 21:47:18 4
Find pages returning 404 errors in apache logs

Finds the top ten pages returning an http response code of 404 in an apache log.
This is sample output - yours may be different.
8

awk '$9 == 404 {print $7}' access_log | uniq -c | sort -rn | head

zlemini · 2010-04-08 21:40:53 12
In place line numbering

Add permanent line numbers to a file without creating a temp file. The rm command deletes file10 while the nl command works on the open file descriptor of file10 which it outputs into a new file again named file10. The new file10 will now be numbered in the same directory with the same file name and content as before, but it will in fact be a new file, using (ls -i) to show its inode number will prove this.
This is sample output - yours may be different.
3

{ rm -f file10 && nl > file10; } < file10

zlemini · 2010-04-08 21:08:23 11
View network activity of any application or user in realtime

The "-r 2" option puts lsof in repeat mode, with updates every 2 seconds. (Ctrl -c quits) The "-p" option is used to specify the application PID you want to monitor. The "-u' option can be used to keep an eye on a users network activity. "lsof -r 2 -u username -i -a"
This is sample output - yours may be different.
16

lsof -r 2 -p PID -i -a

zlemini · 2010-03-16 20:37:16 20
Eavesdrop on your system

This command takes a snapshot of the open files for a PID 1234 then waits 10 seconds and takes another snapshot of the same PID, it then displays the difference between each snapshot to give you an insight into what the application is doing.
This is sample output - yours may be different.
42

diff <(lsof -p 1234) <(sleep 10; lsof -p 1234)

zlemini · 2010-03-15 22:55:32 14
List .log files open by a pid

Uses lsof to display the full path of ".log" files opened by a specified PID.
This is sample output - yours may be different.
6

lsof -p 1234 | grep -E "\.log$" | awk '{print $NF}'

zlemini · 2010-03-05 11:41:28 6
grep -v with multiple patterns.

Use multiple patterns with grep -v. So you can print all lines in a file except those containing the multiple patterns you specify.
This is sample output - yours may be different.
16

grep 'test' somefile | grep -vE '(error|critical|warning)'

zlemini · 2009-10-23 23:21:36 16
Make alias pemanent fast

Simple function to permanently add an alias to your profile. Tested on bash and Ksh, bash version above. Here is the ksh version: PERMA () { print "$@" >> ~/.profile; } Sample usage: PERMA alias la='ls -a'
This is sample output - yours may be different.
2

PERMA () { echo "$@" >> ~/.bashrc; }

zlemini · 2009-09-28 16:03:24 9
< 1 2

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Download latest NVIDIA Geforce x64 Windows driver

Download latest NVIDIA Geforce x64 Windows7-8 driver from Nvidia's website. Pulls the latest download version (which includes beta). This is the "English" version. The following command includes a 'sed' line to replace "english" with "international" if needed. You can also replace the starting subdomain with "eu." "uk." and others. Enjoy this one liner! 1 character under the max :) $wget "us.download.nvidia.com$(wget -qO- "$(wget -qO- "nvidia.com/Download/processFind.aspx?psid=95&pfid=695&osid=19&lid=1&lang=en-us" | awk '/driverResults.aspx/ {print $4}' | cut -d "'" -f2 | head -n 1)" | awk '/url=/ {print $2}' | sed -e "s/english/international/" | cut -d '=' -f3 | cut -d '&' -f1)"

Create a 5 MB blank file via a seek hole

Similar to the original, but is much faster since it only needs to write the last byte as zero. A diff on testfile and testfile.seek will return that they are the same.

Check a server is up. If it isn't mail me.

Alternative to the ping check if your firewall blocks ping. Uses curl to get the landing page silently, or fail with an error code. You can probably do this with wget as well.

Convert all .wav to .mp3

Audio convert is a script that uses zenity and lame to transcode virtually any format to any other format provided you have the libraries installed to do so.

Shows picture exif GPS info if any and converts coords to a decimal degree number

This oneliner uses Imagemagic's identify utility to show the exif GPS information of an image an also converts Grad/MIn/Sec representation to a decimal degree number

Monitor memory without top or htop

It repeats a command, such as free, every five seconds and highlights the differences

Calculates the date 2 weeks ago from Saturday the specified format.

Good for automating reports that need to run from between two dates.

Save a file you edited in vim without the needed permissions

probably just like 1204, but uses tee as a filter (+ I actually understand how this one works)

Escape potential tarbombs

This Anti-TarBomb function makes it easy to unpack a .tar.gz without worrying about the possibility that it will "explode" in your current directory. I've usually always created a temporary folder in which I extracted the tarball first, but I got tired of having to reorganize the files afterwards. Just add this function to your .zshrc / .bashrc and use it like this; $ atb arch1.tar.gz and it will create a folder for the extracted files, if they aren't already in a single folder. This only works for .tar.gz, but it's very easy to edit the function to suit your needs, if you want to extract .tgz, .tar.bz2 or just .tar. More info about tarbombs at http://www.linfo.org/tarbomb.html Tested in zsh and bash. UPDATE: This function works for .tar.gz, .tar.bz2, .tgz, .tbz and .tar in zsh (not working in bash): $ atb() { l=$(tar tf $1); if [ $(echo "$l" | wc -l) -eq $(echo "$l" | grep $(echo "$l" | head -n1) | wc -l) ]; then tar xf $1; else mkdir ${1%.t(ar.gz||ar.bz2||gz||bz||ar)} && tar xf $1 -C ${1%.t(ar.gz||ar.bz2||gz||bz||ar)}; fi ;} UPDATE2: From the comments; bepaald came with a variant that works for .tar.gz, .tar.bz2, .tgz, .tbz and .tar in bash: $ atb() {shopt -s extglob ; l=$(tar tf $1); if [ $(echo "$l" | wc -l) -eq $(echo "$l" | grep $(echo "$l" | head -n1) | wc -l) ]; then tar xf $1; else mkdir ${1%.t@(ar.gz|ar.bz2|gz|bz|ar)} && tar xf $1 -C ${1%.t@(ar.gz|ar.bz2|gz|bz|ar)}; fi ; shopt -u extglob}

Switch to the previous branch used in git(1)

Very useful if you keep switching between the same two branches all the time.

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