first there was the command line
DESCRIPTION
Command line tutorial to be presented at WordCamp Miami 2014TRANSCRIPT
First There was the Command Line
...the first thing that Apple's hackers had done when they'd got the MacOS up and running--probably even before they'd gotten it up and running--was to re-create the Unix interface, so that they would be able to get some useful work done...
-- In the Beginning was the Command LineNeal Stephenson
http://www.slideshare.net/aramonc/learning-the-command-line
Follow along...
$>mkdir -p ~/www/wp_site/news
&& wget http://wordpress.org/latest.zip
&& unzip latest.zip -d
~/www/wp_site/news
Chaining commands with &
Make news directory under /var/www/wp_site, then download latest version of WordPress, then extract the contents of the archive to /var/www/wp_site/news
● Developer at ServerGrove● All around nerd● Systems Administrator for
7 years● @aramonc in all the places
About Me
More than 60% of all web servers use *nix
Why bother?
DebianUbuntu
CentOS/RHELSmartOS*
Servers do not use graphical interfaces*Not really Linux, still Unix based
WordPress Powers ~19% of the web
Why bother?
Statistically more likely to be target of attack
● Increased speed & flexibility● Muscle memory● Large pool of freely available utilities● *nix Command Line utilities are mostly
standard
Why bother?
What if I mess up?
Getting to the Command Line
Windows
Localhost:Cygwin
Webhost:SSH via PuTTY
OSX, *nix
Localhost:Terminal, xterm, etc
Webhost:SSH via the above
Navigating Folders = Directory Tree
Where are you right now?
$>pwd/var/www/wp_site
Print Working Directory
● /var/www/wp_site = a path● / not \● Starts with / (root) = absolute
What’s in here?
$>lsindex.php wp-includeslicense.txt wp-links-opml.phpreadme.html wp-load.phpwp-activate.php wp-login.phpwp-admin wp-mail.phpwp-blog-header.php wp-settings.phpwp-comments-post.php wp-signup.phpwp-config-sample.php wp-trackback.php
LiSt
What’s in here?
$>ls -latotal 320drwxr-xr-x 21 adrian_sg wheel 714 Feb 28 22:07 .drwxr-xr-x 3 root wheel 102 Feb 28 21:57 ..-rw-r--r--@ 1 adrian_sg wheel 640 Mar 05 20:14 .htaccess-rw-r--r--@ 1 adrian_sg wheel 418 Sep 24 20:18 index.php-rw-r--r--@ 1 adrian_sg wheel 19929 Jan 18 2013 license.txt-rw-r--r--@ 1 adrian_sg wheel 7185 Jan 13 13:16 readme.htmldrwxr-xr-x@ 88 adrian_sg wheel 2992 Jan 23 15:17 wp-admindrwxr-xr-x@ 5 adrian_sg wheel 170 Jan 23 15:17 wp-content-rw-r--r--@ 1 adrian_sg wheel 2932 Sep 24 20:18 wp-cron.php
LiSt
Moving around...
$>cd wp-admin$>pwd/var/www/wp_site/wp-admin$>cd /var/www/wp_site$>pwd/var/www/wp_site$>cd wp-content/themes/twentyfourteen$>pwd/var/www/wp_site/wp-content/themes/twentyfourteen
Change Directory
Moving around...
$>cd ..$>pwd/var/www/wp_site$>cd ~/$>pwd/Users/adrian_sg$>cd -$>pwd/var/www/wp_site
Change Directory
Where is this thing?
$>find . -iname xml\*
/var/www/wp_site/xmlrpc.php
$>find . -mtime 3
Find
. (dot) means current directory-mtime in 24 hour increments of modified date
Where is this thing?
$>grep theme ./*
./index.php: * wp-blog-header.php...the theme.grep: ./wp-admin: Is a directory./wp-settings.php:require(ABSPATH.WPINC.'/theme.php');./wp-settings.php:do_action( 'setup_theme' );
Globally search a Regular Expression and Print
Where is this thing?
$>grep -R theme ./*
./wp-admin/update.php: $parent_file='themes.php';
./wp-admin/update.php: $submenu_file='themes.php';
./wp-admin/update.php: $nonce='install-theme_'.$theme;
Globally search a Regular Expression and Print
Can I change things?
$>ls -ltotal 320-rw-r--r--@ 1 adrian_sg wheel 418 Sep 24 20:18 index.php-rw-r--r--@ 1 adrian_sg wheel 19929 Jan 18 2013 license.txt-rw-r--r--@ 1 adrian_sg wheel 7185 Jan 13 13:16 readme.htmldrwxr-xr-x@ 88 adrian_sg wheel 2992 Jan 23 15:17 wp-admindrwxr-xr-x@ 5 adrian_sg wheel 170 Jan 23 15:17 wp-content-rw-r--r--@ 1 adrian_sg wheel 2932 Sep 24 20:18 wp-cron.phpdrwxr-xr-x@ 122 adrian_sg wheel 4148 Jan 23 15:17 wp-includes-rw-r--r--@ 1 adrian_sg wheel 2359 Oct 24 18:58 wp-load.php
Owners, Groups, & Permissions
Can I change things?
Permissions
r = Readw = Writex = Execute (run a script or open a directory)
Three levels of permissions: Owner, Group, Everyone else
Can I change things?
Owner = User● Sometimes your user● Sometimes root● Sometimes www-data (Apache user)
Can I change things?
Group● Permissions for a set of users● Users have own group● Most users only belong to own group
Can I change things?
Permissions
Owner Group EveryoneIs Dir.?
rwx r-x r-xd
$>ls -ldrwxr-xr-x@ 88 adrian_sg wheel 2992 Jan 23 15:17 wp-admin
adrian_sg wheel
How do I change this thing?
$>mkdir -p useless/stuff
$>ls -l-rw-r--r--@ 1 adrian_sg wheel 418 Sep 24 20:18 index.php-rw-r--r--@ 1 adrian_sg wheel 19929 Jan 18 2013 license.txt-rw-r--r--@ 1 adrian_sg wheel 7185 Jan 13 13:16 readme.htmldrwxr-xr-x 2 adrian_sg wheel 68 Mar 3 22:04 useless-rw-r--r--@ 1 adrian_sg wheel 4892 Oct 4 10:12 wp-activate.php
MaKe DIRectory
How do I change this thing?
$>mv readme.html useless/stuff/readme
$>ls -l
-rw-r--r--@ 1 adrian_sg wheel 418 Sep 24 20:18 index.php-rw-r--r--@ 1 adrian_sg wheel 19929 Jan 18 2013 license.txtdrwxr-xr-x 2 adrian_sg wheel 68 Mar 3 22:04 useless-rw-r--r--@ 1 adrian_sg wheel 4892 Oct 4 10:12 wp-activate.php
MoVe
How do I change this thing?
$>cp wp-config-sample.php wp-config.php
$>ls -l
-rw-r--r--@ 1 adrian_sg wheel 4795 Sep 5 21:38 wp-comments-post.php-rw-r--r--@ 1 adrian_sg wheel 3087 Oct 24 18:58 wp-config-sample.php-rw-r--r--@ 1 adrian_sg wheel 3087 Mar 3 21:59 wp-config.phpdrwxr-xr-x@ 5 adrian_sg wheel 170 Jan 23 15:17 wp-content
CoPy
● cp -a keeps same permissions as original
When everything goes wrong...
$>less
/var/log/apache2/error_log
Read the log file
When everything goes wrong...
Read the log file
● (up arrow) to scroll towards the top● (down arrow) to scroll towards the bottom● (space) next page● p previous page● q(uit) to exit● / <expression> to search for <expression>● n to search again
But I only care about the last error...
$>tail -n 5 /var/log/apache2/error_log[Mon Mar 03 10:28:01 2014] [notice] Digest: generating secret for digest authentication ...[Mon Mar 03 10:28:01 2014] [notice] Digest: done[Mon Mar 03 10:28:01 2014] [notice] Apache/2.2.26 (Unix) DAV/2 PHP/5.5.4 mod_ssl/2.2.26 OpenSSL/0.9.8y configured -- resuming normal operations[Mon Mar 03 13:40:08 2014] [notice] child pid 8870 exit signal Bus error (10)[Mon Mar 03 18:02:20 2014] [notice] caught SIGTERM, shutting down
Read the last few lines of the log file
I only care about the current error...
$>tail -f /var/log/apache2/error_log[Mon Mar 03 10:28:01 2014] [notice] Digest: generating secret for digest authentication ...[Mon Mar 03 10:28:01 2014] [notice] Digest: done[Mon Mar 03 10:28:01 2014] [notice] Apache/2.2.26 (Unix) DAV/2 PHP/5.5.4 mod_ssl/2.2.26 OpenSSL/0.9.8y configured -- resuming normal operations[Mon Mar 03 13:40:08 2014] [notice] child pid 8870 exit signal Bus error (10)[Mon Mar 03 18:02:20 2014] [notice] caught SIGTERM, shutting down
[Mon Mar 03 20:18:01 2014] [notice] Apache/2.2.26 (Unix) DAV/2 PHP/5.5.4 mod_ssl/2.2.26 OpenSSL/0.9.8y configured -- resuming normal operations
Read the log file as it happens
● -f is interactive● Ctrl+C to exit interactive
Who is currently on my site?
$>tail -f /var/log/apache2/*access_log::1 - - [26/Dec/2013:09:35:23 -0500] "OPTIONS * HTTP/1.0" 200 -127.0.0.1 - - [26/Dec/2013:09:35:34 -0500] "GET / HTTP/1.1" 200 44127.0.0.1 - - [26/Dec/2013:09:35:34 -0500] "GET /favicon.ico HTTP/1.1" 404 209127.0.0.1 - - [26/Dec/2013:09:36:40 -0500] "GET / HTTP/1.1" 304 -127.0.0.1 - - [26/Dec/2013:09:36:42 -0500] "GET / HTTP/1.1" 304 -
Read the access log as it happens
How do I change this thing
$>nano wp-config.php
Nano text editor
How do I change this thing
$>nano wp-config.php
^G Get Help ^O WriteOut ^R Read File ^Y Prev Page ^K Cut Text ^C Cur Pos^X Exit ^J Justify ^W Where Is ^V Next Page ^U UnCut Text ^T To Spell
Nano text editor
Putting it all together
$>tail -n 10000
/var/log/apache2/error_log | grep “Mar
01” | less
Deep filtering with the pipe statement
Look for any log entry that occurred on March 1st within the last ten thousand lines of the error log and display it in a way I can easily navigate
Putting it all together
$>mkdir -p wp-content/uploads && echo -
e "RemoveHandler .php .phtml .php3
php4\nRemoveType .php .phtml .php3
php4" > wp-content/uploads/.htaccess
Creating files without a text editor
Make a new uploads directory in wp-content, then create a .htaccess file in uploads with the contents of “RemoveHandler .php .phtml .php3 php4RemoveType .php .phtml .php3 php4”
Resources
● Usage Share of Server OSes
● In The Beginning Was the Command Line
● linuxcommand.org
● 5-Minute Essential Shell Tutorial
● PuTTY
● Cygwin
Questions?
Thank you!http://www.slideshare.net/aramonc/learning-the-command-line