Commands by rockon

Commands by rockon (18)

sorted by

Find processes utilizing high memory in human readable format

Finding high memory usage report in human readable format. Show Sample Output

ps -eo size,pid,user,command --sort -size |awk '{hr[1024**2]="GB";hr[1024]="MB";for (x=1024**3; x>=1024; x/=1024){if ($1>=x){printf ("%-6.2f %s ", $1/x, hr[x]);break}}}{printf ("%-6s %-10s ", $2, $3)}{for (x=4;x<=NF;x++){printf ("%s ",$x)} print ("\n")}'

rockon · 2012-11-27 04:29:08 11

Server load and process monitoring

In certain cases you mighy need to monitor the server load caused by certain process. For example HTTP, while stress testing apache using ab (apache benchmark) you may want to monitor the server status,load, # of spawned HTTP processes, # of established connections, # of connections in close wait state, apache memory footprint etc. Show Sample Output
This is sample output - yours may be different.
```
load average: 0.11, 0.10, 0.03
39
27
46
total used free shared cached
Mem: 4050 3096 953 202 
Swap: 8197 114 8083
HTTP_RSS
2720
2744
3336
```
2

watch -n1 "uptime && ps auxw|grep http|grep -v grep | grep -v watch|wc -l && netstat -ntup|grep :80 |grep ESTABLISHED|wc -l && netstat -ntup|grep :80|grep WAIT|wc -l && free -mo && ps -ylC httpd --sort:rss|tail -3|awk '{print \$8}'"

rockon · 2012-06-06 12:12:10 5
Check which modules your PHP is using
This is sample output - yours may be different.
1

php -m

rockon · 2012-05-27 12:08:52 3
See loaded modules in apache

Easiest way to check which modules are loaded in apache. Show Sample Output
This is sample output - yours may be different.
```
# httpd -M
Loaded Modules:
 core_module (static)
 mpm_prefork_module (static)
 http_module (static)
 so_module (static)
 authn_file_module (shared)
```
1

httpd -M

rockon · 2012-05-27 12:04:17 6
Know SELinux status

Usefule to check whether SELinux is in force or disabled. Though you need to be superuser while execute this command. Show Sample Output
This is sample output - yours may be different.
```
# sestatus -v
SELinux status:                 disabled
```
1

sestatus -v

rockon · 2012-05-27 11:48:25 4

Mysql extended status

Useful when checking MySQL status. Show Sample Output

mysqladmin -u root -p extended-status

rockon · 2012-05-27 11:38:11 34

Download SSL server certificate with opsnessl

Useful when we need to create new certificate for site when current one is near expiry. This downloaded cert can be used to provide organisational data directly to new cert. using below command. e.g. openssl x509 -x509toreq -in /tmp/example.com.cert -out example.com.csr -signkey example.com-key.pem Show Sample Output
This is sample output - yours may be different.
```
openssl x509 -in /tmp/example.com.cert -noout -startdate -enddate
notBefore=May 03 18:06:47 2012 GMT
notAfter=May 02 17:28:01 2013 GMT
```
2

openssl s_client -connect www.example.com:443 > /tmp/example.com.cert

rockon · 2012-05-04 06:15:27 6

Generate the CPU utilization report

Generated the CPU utilization stats with 5 lines /every 2 seconds. Needs sysstat package to be installed prior to use sar. Show Sample Output

sar -u 2 5

rockon · 2009-03-02 04:54:37 10

List the files any process is using

List the files a process is using.
This is sample output - yours may be different.
16

lsof +p xxxx

rockon · 2009-03-02 04:49:23 18
cp the file

Copy the file with the given .extension at the source file's location. Eliminates the typing of long paths again and again. Show Sample Output
This is sample output - yours may be different.
```
cp /some/path/to/myfile{,.back}

ls /some/path/to/
myfile
myfile.back
```
1

cp /some/path/to/myfile{,.back}

rockon · 2009-03-02 04:41:18 7

Traffic stat on ethernet interface

Traffic details on the Ethernet interface. Show Sample Output

-1

ethtool -S eth0

rockon · 2009-03-01 10:25:46 5

search the pattern from bzip2'ed file

Search the pattern in bzip2 compressed file with out having to unzip. Show Sample Output
This is sample output - yours may be different.
```
bzgrep -i "pattern" pattern.bz2

>This is my pattern.
```
0

bzgrep -i "pattern" pattern.bz2

rockon · 2009-03-01 10:21:26 5
pinky - user info

Gives information about user's home directory and real name and shell user is having. Show Sample Output
This is sample output - yours may be different.
```
pinky -l xyz
Login name: xyz                   In real life:  xyz xyz
Directory: /home/xyz              Shell:  /bin/bash
```
2

pinky -l <username>

rockon · 2009-03-01 10:17:08 10
hard disk information - Model/serial no.

Get the hard disk information with out shutting down and opening the system. It gives information on model no., serial no., cylinders/heads/sectors, and the supported features of the hard disk. Show Sample Output
This is sample output - yours may be different.
```
hdparm -i /dev/sda | grep -i model
	Model Number:       ST3160815AS
```
10

hdparm -i[I] /dev/sda

rockon · 2009-03-01 10:00:28 16
Know your distro

To know the OS distro and version, release. Is same like /etc/redhat-release Show Sample Output
This is sample output - yours may be different.
```
lsb_release -a
Distributor ID:	Ubuntu
Description:	Ubuntu 8.10
Release:	8.10
Codename:	intrepid
```
0

lsb-release -a

rockon · 2009-03-01 09:42:52 7
Getting information about model no. of computer

This command gives a model information of a computer. Also useful in determining the host is a VM machine or actual physical machine. Show Sample Output
This is sample output - yours may be different.
```
dmidecode | grep -i prod
       Product Name: HP dx2480 MT(FX800PA)
       Product Name: 0B08h
```
6

dmidecode | grep -i prod

rockon · 2009-02-25 23:05:17 8
Filtering IP address from ifconfig usefule in scripts

Useful in scripts while you just need an IP address in a variable. Show Sample Output
This is sample output - yours may be different.
```
IPADDR=`ifconfig | grep -i inet | awk -F: '{print $2}'| awk '{print $1}'`

echo $IPADDR
193.122.18.101
```
0

IPADDR=`ifconfig eth0 | grep -i inet | awk -F: '{print $2}'| awk '{print $1}'`

rockon · 2009-02-25 22:58:19 13
Delete tens of thousans of files at one go

Deletes thousands of files at one go, I'm not able to recall the exact # of files that rm can delete at one go(apprx. around 7000.)
This is sample output - yours may be different.
-3

rm -rf `ls | head -5000`

rockon · 2009-02-25 22:52:23 7

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

Summarize the number of open TCP connections by state

Useful for checking the number and state of TCP connections.

Check the current price of Bitcoin in USD

Convert CSV to JSON

Replace 'csv_file.csv' with your filename.

List files by quoting or escaping special characters.

Tested and works on Linux.

Recompress all .gz files in current directory using bzip2 running 1 job per CPU core in parallel

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"

Copy via tar pipe while preserving file permissions (run this command as root!)

It's the same like 'cp -p' if available. It's faster over networks than scp. If you have to copy gigs of data you could also use netcat and the tar -z option in conjunction -- on the receiving end do: # nc -l 7000 | tar -xzvpf - ...and on the sending end do: # tar -czf - * | nc otherhost 7000

Get mouse location (X,Y coordinates)

Extract .tar.lzma archive

Scan for nearby Bluetooth devices.

Scans local area for visible Bluetooth devices. Use 'hcitool inq' to discover the type of device it is. And use -i hciX option to specify the local Bluetooth device to use.

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:

» all commands
» commands with 3 up-votes (commandlinefu3)
» commands with 10 up-votes (commandlinefu10)
» commands by rockon