| cd [dir] |
Change the current working
directory to dir.
To change the current working directory to
/www/cgi-bin
$ cd /www/cgi-bin |
| chmod mode
file |
Change the access permissions of
FILE to MODE.
To set the permissions for the
index.html to rwxr-xr-x
<>$ chmod 755
index.html
For more details on modes and permissions
refer to the section on Linux
permissions |
| cp source
dest |
Copy a file or directory from
the SOURCE location to the DEST location.
$ cp docs/index.html
vhtdocs/list.html
copies
index.html in the docs directory into the vhtdocs
directory but with the filename list.html.
$ cp docs/index.html
vhtdocs
copies index.html
in the docs directory into the vhtdocs directory preserving
the filename. |
| cat file |
Read one or more files and print
them to standard output
To output the contents of readme.txt
to the screen
$ cat readme.txt
To append the contents of readme.txt
to readme.1st
$ cat readme.txt >>
readme.1st |
| ls name |
List the contents of directory
NAME or display information about the file NAME.
To list the contents of
/www/cgi-bin
$ ls /www/cgi-bin
To list the contents of /www/cgi-bin,
including hidden files, in long format
$ ls -al
/www/cgi-bin |
| mv source
dest |
If DEST is a directory then move
the file or directory SOURCE into the directory DEST.
If DEST is
not a directory then rename the file or directory SOURCE to
DEST.
To rename readme.1st to
readme.txt
$ mv readme.1st
readme.txt
To move docs/index.html to the
directory vhtdocs
$ mv docs/index.html
vhtdocs |
| mkdir
dir |
Create a new directory called
DIR
To create the directory test in the
current working directory
$ mkdir test |
| less
file |
less is a filter for paging
through text one screenful at a time.
To view the Apache webserver error log
$ less /var/log/httpd/error_log
Press key Q to exit the
pager. |
| rm name |
Delete a file or directory
called NAME.
To delete the file readme.1st
$ rm readme.1st
To delete the empty directory
temp
$ rm temp
To delete a non-empty directory called
temp
$ rm -r temp
To delete a file or directory without being
prompted (use with caution)
$ rm -f temp |
| tail
file |
Output the last part of
files
To display the last ten lines of
/var/log/httpd/error_log
$ tail -f
/var/log/httpd/error_log
To display the last 100 lines of
/var/log/httpd/access_log
$ tail -n 100 -f
/var/log/httpd/error_log |
| su user |
Run a command with substitute
user and group id. This command is typically used to take on the persona
of another user. The user's password is required.
To take on the persona of the web user
$ su web |
| chown user[.group]
file |
Change the user and group ownership of
files.
To make the file index.html owned by the user
web
$ chown web index.html
To make the file index.html owned by the user
web and owned by group admin
$ chown
web.admin index.html
To change the ownership of a directory and
all files within it to user admin and group web
$ chown -R admin.web /home/httpd/docs |
| chgrp group file |
Change the group ownership of files.
This works similarly to chown however only
the group ownership can be changes
To make the file index.html owned by group
web
$ chgrp web index.html |
| chmod mode file |
Change the access permissions of
files.
To make the script test.sh owner
read/write/execute, group read/execute and world read/execute:
$ chmod 0755 test.sh |
| top |
Provide an ongoing look at the
most CPU-intentive processes on the Virtual Server.
Usage:
$ top |
| ps
options |
Reports the status of
processes
To list all processes running on the virtual
server
$ ps a
To list all processes running, including
memory and CPU usage statistics:
$ ps au |
| kill -signal
pid |
kills a specific process, the
process ID can be ascertained from ps or top
Send the process PID the signal SIGNAL. PID
is the identification number of the process and SIGNAL is a number
mapped to a signal name.
To retrieve a list of available signal
numbers:
$ kill -l
To send an interrupt signal (SIGINT) to
process 1852
$ kill -2 1852 |
| pwd |
Print the current working
directory
$ pwd |
| grep options
filename |
Search one or more files for
lines that match a regualr expression
To search for the word rabbit in all
.html files in the current directory
$ grep -E "rabbit"
*.html |
| man [section]
name |
Display information from the
on-line reference manuals
To display the manpage for the grep
command
$ man grep
For names like open there may be many
different man pages. Commonly references to man pages are written, "see
open(2)". The number in parentheses refers to the section number.
To view man page open(2)
$ man 2 open
To view all man pages associated with
open
$ man -a open
and press the Q key to move to the next page. |
tar options
filename...
tar options directory... |
Tar is an archiving program
designed to store and extract files from an archive file known as a
tarfile.
To create an archive of the conents of the
directory /home/httpd
$ tar -cvf web.tar /home/httpd
To extract all files from web.tar into
the current working directory
$ tar -xvf web.tar
Additionally the z flag may be applied
to compress the tarfile using gzip.
$ tar -czvf web.tar
/home/httpd
It is important that the f flag comes
last in the options as this takes a filename as a parameter, in the
examples above it was web.tar.
To add readme.txt to an already
existing tarfile
$ tar -Avf web.tar readme.txt
To extract readme.txt from
web.tar
$ tar -xvf web.tar readme.txt |
| pico
file |
A simple text
editor
To edit index.html in the current
working directory
$ pico index.html |
| vi file |
A programmers text editor
To edit index.html in the current
working directory
$ vi index.html
Upon startup the editor is immediately placed
into command mode. To enter text you need to be in insert mode, press
key i. To return back to command mode, press the escape
key.To exit the vi editor, enter :q in command
mode. |
| nslookup
domainname |
A utility to query Internet
domain name servers interactively
To query the nameservers for
your-domain.co.uk, returning the corresponding IP address if
present.
$ nslookup your-domain.co.uk |
| whois
domainname |
Search an Internet directory for
the person, login, handle or organisation of a domain name.
To retrieve information about the owner of
the domain gnome.org
$ whois gnome.org |
| date |
print the current date and
time
$ date |