Frequently Used Commands - tlam/Wiki GitHub Wiki

Grepping multiple keywords(CRITICAL, ERROR or WARNING) from a file:
```
 grep -E "CRITICAL|ERROR|WARNING" log.txt
```
Remove all files of a specific extension:
```
 find . -name "*.pyc" | xargs rm
```
Testing a new domain name In @/etc/hosts@, set the server's IP to the new domain name:
```
 xx.xxx.xx.xx  my-new-domain-name.com
```

Delete files older than 5 days

 find . -name "*.css" -mtime +5 -delete

Find for a specific pattern(Country) in a file(*.py) and excluding searching in a specific folder(migrations)
```
 find . -name "*migrations*" -prune -o -name "*.py" -print | xargs grep "Country"
```

Tar and gzip a folder

 tar -cvf my_folder.tar my_folder/
 gzip my_folder.tar

Changing default subversion user

Remove the file containing the current user from @.subversion/auth/svn.simple@
Run an svn up and specify the new username

Search for a keyword in specific files

 find . -name "*.py" -print | xargs grep "print" -n

Determine public IP
```
 curl http://api.externalip.net/ip
```
Top - The three load-average values in the first line of top output are the 1-minute, 5-minute and 15-minute average.
Unzip a bz2
```
 tar -xvjpf somepackage.tar.bz2
```
Running memcached on Mac
```
 memcached -d -p 11211
```
Find all symlinks from the current directory:
```
 find . -type l -exec ls -l {} \;
```
Trace and ping together or online http://www.websitepulse.com/help/testtools.mtr-test.html:
```
 mtr stackoverflow.com
```
Show which processes are using a file, sometimes it only works with sudo
```
 fuser logfile.log
```
Testing slow response from website
```
 time curl -v https:/example.com
```

Get public IP from server:

 dig TXT +short o-o.myaddr.l.google.com @ns1.google.com

Check network connection to a rabbitmq server
```
 nc -v somequeue 5672
```
Check deleted opened files
```
 lsof | grep deleted
```
Check inodes usage
```
 df -i
```

vi

.vimrc

 set tabstop=4
 set shiftwidth=4
 set expandtab
 set autoindent

Delete all lines with keywords:
```
 :g/somekeywords/d
```

Search and replace

 :%s/search_string/replacement_string/g

Remove ^M characters:
```
 :%s/[ctrlkey+v and ctrl-key+M]//g
```
Copy entire file to clipboard(Mac):
```
 :%w !pbcopy
```
If the colour scheme is too bright on a white background, try the following colour scheme under .vimrc:
```
 colorscheme delek
```

Vim Pathogen

Create the folder .vim/bundle if it does not exist

From .vim/bundle, install vim-pathogen:

 git clone https://github.com/tpope/vim-pathogen.git

In your .vimrc file, add the following to the top:

  " enable vim-pathogen
  runtime bundle/vim-pathogen/autoload/pathogen.vim
  execute pathogen#infect()

You can then install custom themes such as onedark under .vim/bundle with:
```
 git clone https://github.com/joshdick/onedark.vim
```
Activate the theme by adding the following in your .vimrc:
```
 colorscheme onedark
```

Apache

Could not reliably determine the server's fully qualified domain name, using 127.0.0.1 for ServerName

Assuming your server has hostname lnx-something and IP a.b.c.d, add the following line in /etc/hosts:

    a.b.c.d lnx-something

Understanding Apache, SSL, VirtualHost

VMWare

A VM can made accessible to a network by:
```
 Virtual Machine > Settings > Network
```

Change the network adapter is configured to: Connect directly to the physical network (Bridged) Using: Autodetect

Speed improvement on Mac. If your mac runs VMWare Fusion and the laptop is slow, shut down printer sharing.
1. Select VMWare Fusion
2. Virtual Machines > Settings > Printer
3. Toggle Share Mac printers with Linux to OFF

Regular expression tester

Regex 101

RabbitMQ

Check for any pending messages:

sudo rabbitmqctl list_queues name messages messages_unacknowledged messages_ready consumers

SASS

In case of the following error Error: File to import not found or unreadable: compass, set the SASS_PATH:

export SASS_PATH=$BASE/static:$BASE/other_locations

Virtual Box

Use Bridged Adapter to allow ssh into the guest vm. Another way: http://stackoverflow.com/questions/5906441/how-to-ssh-to-a-virtualbox-guest-externally-through-a-host

Vagrant - Run specific tags

In the Vagrantfile, set the tags

ansible.tags = "some-task"

Running vagrant provision will only run some-task

Alternatively:

ANSIBLE_TAGS="some-tasks"; vagrant provision

Ansible

Private keys can have their new line characters preserved by storing them between single quotes in the vault file, for example:

private_key: '----PRIVATE KEY---- abc\n123\ndef\n---'