Unix Tools
Getting Around
• pwd
– Print Working Directory
– Tells you where you are on the remote computer
Getting Around
• LS
– Lists directory contents
L flag for ‘long list’
everyone
group
owner
directory
Getting Around
W = writable
R = readable
X = executable
owner
size
date
name
Getting Around
• cd
Go to the root of the server
From there, go to the folder called ‘afs’
Now you’re in /afs
Operations
• Chown
– Changes ownership of a file or folder
chown [user] [file]
chown gillw3 /var/logs
chown –R gillw3 /var/logs
Changes ownership of the folder ‘logs’
Changes ownership of the folder ‘logs’
and everything in it
Operations
• chmod
– Modifies access rules for a file
chmod [usertype] = [rights] [file]
[usertype] can be one of u, g, or o
(current owner, anyone in the owners group, anyone)
[rights] can be r, w or x
(read, write, execute)
Operations
• chmod
chmod u=rwx somefile.txt
Operations
• cp
– Copies a file
cp [source] [destination]
cp somefile.txt somefile_copy.txt
Operations
• mv
– Moves a file
mv [source] [destination]
mv somefile.txt newname.txt
mv somefile.txt /var/www/somefile.txt
(renames)
(moves)
Operations
• rm
– Removes a file
rm [file]
rm somefile.txt
Operations
• wget
– Gets a file (or more) from a web resource
wget [url]
wget http://www.rpi.edu/index.html
(gets file, saves it to current directory as index.html)
wget –O rpihome.html http://www.rpi.edu/index.html
(gets file, saves it to current directory as rpihome.html)
.sh files
• Put shell commands in a file
• Call the file, all the commands run
The following should be the top line of the file:
#!/bin/sh
Operations
• cron
– allows users to set timers for operations to be
exicuted
• crontab
– A file that specifies what should be done when
Operations
• Crontab
– Crontab –e (edits file)
[min] [hour] [day of month] [month] [day of week] [command]
[0-59, *] [0-23, *] [1-31, *] [1-12, *] [0-6, *] [command]
0,5,10,15,20,25,30,35,40,45,50,55 * * * * update-rss-feeds.sh
0 3 * * * managelogs.sh
Apache Webserver
Apache Webserver = httpd
• Hypertext transfer protocol daemon
– Daemons are applications that run all the time
listening for a request. When a request is made
they do something.
• Developed in 1995
• Serves 50% of websites
HTTPD is Modular
• mod_php is added to allow php to be
processed….
• Modules may be added when the application
is complied
• Modules may be dynamically added after the
application is complied
– apxs is a tool for managing dynamic modules
– http://httpd.apache.org/docs/2.2/programs/apxs.html
Modules in httpd.conf
Modules
• mod_auth_cas
– http://www.ja-sig.org/wiki/display/CASC/mod_auth_cas
• mod_auth_ldap
– http://httpd.apache.org/docs/2.0/mod/mod_auth_ldap.html
• mod_proxy_fcgi
– http://mproxyfcgi.sourceforge.net/
Configuring in httpd.conf
• Httpd.conf is read when httpd starts
• Restart httpd every time you edit httpd.conf
• At all times, refer to the apache documenation
– http://httpd.apache.org/docs/2.2/
httpd.conf
• <directory>
– Rules for a folder on the server
• <location>
– Rules for a url
• <virtualhost>
– Directive that creates additional hosts on your httpd
instance.
• <IfModule>
– Tests of a module is loaded before you attempt to
configure the module
<directory>
Allows server side includes in the specified folder
Instructs httpd to follow shortcuts in the filesystem, to ignore .htaccess files,
do not serve any content
<location>
Requires AFS login to any URL that has an /AFS in the path
<virtualhost>
Creates a virtual host, alert.rpi.edu
<IfModule>
Only runs the re-write rules if mod_rewrite is loaded
.htaccess
• Contains instructions, like those found in
httpd.conf
• File is parsed every time the server requests a
resource in that folder, or a downstream
folder
In Class Work
• Using mod_rewrite to
– Proxy
– Make neato urls
• Create a httpd servable directory named
‘rewrite’
In Class Work
Allowing .htaccess files in httpd.conf
• Add the following to httpd.conf
<Directory /path/to/www/rewrite>
AllowOverride All
</Directory>
• Restart httpd
In Class Work
• Create a file named .htaccess in ‘rewrite’
• Add:
<IfModule mod_rewrite.c>
RewriteEngine on
RewriteBase /rewrite/
RewriteRule ^(.*)$ http://www.cnn.com/ [P]
</IfModule>
In Class Work
• Go to http://localhost/rewrite
• Rename .htaccess to example1.txt
• Create another file named .htaccess
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteRule /(.*) index.php?input=$1
</IfModule>
In Class Work
• Create index.php
1. echo $_GET[‘input’];
2. Use ‘explode’ on $_GET[‘input’] to break the
input into value key pairs