| Command | What it does | Example | Notes |
| cd | changes the directory | cd /var/www |
|
cd ..
| jumps up one directory
| cd ..
|
|
| ls | lists files/sub dirs in the directory that you are in | ls /var/www
|
|
ls -l
| lists all of the info about the files
| ls -l /var
|
|
ls -h
| list all files and converts the file size into KB, MB etc as opposed to bytes
| ls -h
|
|
ls -al
| shows information about the files including: owner, permissions, last modified | ls -al /var/www |
|
ls -R
| Shows recursively all of the files/subdirectories under a dir
| ls -R ~/backup | This will breakdown the contents of the backup folder and display also any sub dirs with their files
|
| ls -m
| Lists files/dirs in a comma separated list
| ls -m ~/ |
|
ls -a
| shows all of the files - even hidden files
| ls -a ~/
|
|
ls -F
| shows full names of files in the list
| ls -F ~/
|
|
pwd
| gives current location in the filesystem
| pwd
|
|
| nano | nano is a text editor for editing files in Linux | nano /var/www/test.txt | vi is another text editor that you can use. To use vi supplemnet nano with vi |
chown
| changes the owner of a file or directory | chown bob /var/www |
|
| rmmod pcspkr | removes beeping noise from the computer if you make an error
|
| Came in handy for me when I had to edit in the console of a virtual machine
|
CTRL C
| exits out of what you are doing |
| When you want to exit a program or script that is running too long |
| ifconfig | gets network settings for your computer | ifconfig | shows IP address, handy for VMs. |
| chmod | change the permissions for a directory/file | chmod 775 /etc/program/* | permissions are beneficial for locking down files and directories |
adduser username
| this adds another user to the operating system
| adduser corey
|
|
passwd
| allows you to change your password
| passwd
| this will change the password for the user you are logged in as
|
visudo
| this opens the editor for the sudo(super user) privledges
|
| If you add a new user that you want to have admin privledges, then you'll want to us this command
|
gzip
| compresses a file
| gzip file.sql
| Handy when backing up large file(s)
|
gzip -d
| uncompresses a zipped folder
| gzip -d file.gz
| note that this will only uncompress files with the gz extension
|
cp
| copies a file/directory to a diff directory
| cp web/* /var/www/ | note that you put cp which copies, then the directory or file you want to copy and a space then the dir that you want to move it to
|
*
| Wildcard
| rm libby1*.jpg | libby10.jpg through libby12.jpg, as well as libby1.txt |
[ ]
| Wildcard
| rm libby1[12].jpg | libby11.jpg and libby12.jpg, but not libby10.jpg |
?
| Wildcard
| rm libby1?.jpg | libby10.jpg through libby12.jpg, but not libby1.txt |
scp
| Another file transfer option
| scp file1.txt root@www.site.com:somedir
| make sure you have login access to the server you are transferring it to
|
mkdir
| makes a new directory
| mkdir test
|
|
mkdir -p
| allows you to make subdirs in a new directory
| mkdir -p test/test1/test2
| test1 will be a subdir of test. test2 will be a subdir of test1
|
mkdir -v
| shows the actions of the mkdir command
|
|
|
mv
| Move
| mv /var/test/test.txt /var/www/
| you can rename the file/dir by specifying the name in the path that you are moving it to
|
man -k
| list commands that contain a word
| man -k list
| this helps if you know what you want to do but don't know what the command is
|
--help
| any command you can append --help to it to find out how to use it and its variables
| ls --help
|
|
locate
| this will help find files in the system
| locate test
| if it cannot find it try running updatedb then try it again
|
;
| you can run multiple commands at once with a ; in between them
| cd /etc/ ; cp test.txt /etc/test
| This is helpful when you want to run a lot of commands at once
|
&&
| putting && between commands will confirm that each command was succesfull before moving onto the next command
| cd /etc/ && cp test.txt /etc/test | This is helpful when a series of commands is performed, but if one fails causes a lot of issues
|
| $()
| allows you to substitute a command output
| $ date "+%Y-%m-%d"
2005-11-24
$ mkdir $(date "+%Y-%m-%d")
|
|
cat
| shows the contents of a file without having to open it in an editor
| cat test.txt
| cat's main purpous is to concatonate, which mean join together..helpful when you want to mash together two or more files
|
dog
| similar to cat, but can pull content off the web
| dog http://www.google.com |
|
|
| the "pipe" can submit the output of one command into the input of another command
| ls -1 | less | the command shown will take the output of the list command and apply it to the less command which will decrease the amount of results
|
>
| take the output of a command and puts it into a file
| ls -l >thislist.txt
| if thislist.txt doesn't exist it will be created, if it does it will be overwritten
|
>>
| same as > but appends the previous information so that it won't overwrite the file
| ls -l >>thislist.txt
|
|
less
| shows one page at a time for large files
| less encyclopedia.txt
| Table 5.1. Key Commands for less | Key Command | Action | | PageDn, e, or spacebar | Forward one page | | PageUp or b | Back one page | | Return, e, j, or down arrow | Forward one line | | y, k, or up arrow | Back one line | | G or p | Forward to end of file | | 1G | Back to beginning of file | | Esc-), or right arrow | Scroll right | | Esc-(, or left arrow | Scroll left | | Q | Quit less | |
head
| gives the first 10 lines of a file
| head test.txt
| you can see the first 10 lines of multiple files by seperating the files by spaces
|
tail
| see the last 10 lines of a file
| tail test.txt
|
|
tail -f
| shows the last 10 lines as it updates
| tail -f test.txt
| helpful if you are looking at log files as if you just run tail you will keep having to run it
|
grep
| allows you to search for text inside of files/dirs
|
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