SSH Cheat Sheet

This page designed to help beginners starting out with SSH by providing a usable “SSH cheat sheet” full of common commands.

Delete an entire directory and all of its contents:

rm -r -f YourDirectory What’s happening: rm = remove / delete -r = recursively deletes the directory and all files in it, including subdirectories -f = will not ask for confirmation before deleting

Extract a TAR.GZ File

tar -xvf yourfilename.tar.gz What’s happening: tar – is calling the tar program -x – extract -z – it’s gzipped (so omit the z if you merely have a .tar file) -f – supplying filename on command line.

Move a directory and/or files to another location on the server:

mv directory/* html/ What’s happening: mv – move directory/* – All files/folders inside the Directory folder html/ – Location of where the files will be moved to

Note: When something is specified in brackets, such as [command] or [filename], it is used to indicate that you must input your desired information here. Do NOT include brackets in your command. Navigating in UNIX

pwd	Shows the full path of the current directory
ls	Lists all the files in the current directory
ls -al	Lists all files and information
ls –alR	Lists all files and information in all subdirectories
ls -alR | more	Same as ls –alR, pausing when screen becomes full
ls -alR > filename.txt	Same as ls –alR, outputs the results to a file
ls *.html	Lists all files ending with .html
cd [directory name]	Changes to a new directory
cd ..	Changes to directory above current one
clear	Clears the screen
vdir	Gives a more detailed listing than the “ls” command
exit	Log off your shell

Moving, Copying and Deleting Files

mv [old filename] [new filename]	Move/rename a file
cp [filename] [new filename]	Copies a file
rm [filename]	Deletes a file
rm *	Deletes all files in current directory
rm *.html	Deletes all files ending in .html

Creating, Moving, Copying and Deleting Directories

mkdir [directory name]	Creates a new directory
ls -d */	Lists all directories within current directory
cp -r [directory] [new directory]	Copies a directory and all files/directories in it

Searching Files and Directories

find . -name [filename] -print	Searches for a file starting with current directory
grep [text] [filename]	Searches for text within a file

File and Directory Permissions There are three levels of file permissions: read, write and execute.  In addition, there are three groups to which you can assign permissions: file owner, user group and everyone.  The command chmod followed by three numbers is used to change permissions.  The first number is the permission for the owner, the second for the group and the third for everyone.  Here are how the levels of permission translate:

0 = —	No permission
1 = –X	Execute only
2 = -W-	Write only
3 = -WX	Write and execute
4 = R–	Read only
5 = R-X	Read and execute
6 = RW-	Read and write
7 = RWX	Read, write and execute

It is preferred that the group always have permission of 0.  This prevents other users on the server from browsing files via Telnet and FTP.  Here are the most common file permissions used:

chmod 604 [filename]	Minimum permissions for HTML file
chmod 705 [directory name]	Minimum permissions for directories
chmod 755 [filename]	Minimum permissions for scripts & programs
chmod 606 [filename]	Permissions for data files used by scripts
chmod 703 [directory name]	Write-only permissions for public FTP uploading

How do I unzip a file with telnet?

All of the below commands assume that you are within the same directory that the compressed file is in. To be sure type: ls {enter} If the file is there, you’re ready to go. If not type: cd /big/dom/xdomain/www/directory/ {enter} replacing the path with the correct path to your file. If a file ends in .zip (for example, file.zip) type: unzip file.zip If a file ends in .tar (e.g., file.tar) type: tar -xvf file.tar If a file ends in .gz (for example, file.gz) type: gzip -d file.gz If a file ends in .tar.gz (e.g. file.tar.gz) type: gzip -d file.tar.gz and then tar -xvf file.tar If a file ends in .tgz (e.g. file.tgz)

zip [options] [zipfile] [files] The zip command compresses a file or list of files into a zip format archive file. This command is compatible with pkzip on a PC. Simply type “zip zipfile file1 file2 file3″ at a telnet command prompt and replace zipfile with the name you want to use for your compressed zip archive file, and replace fileX with the name of the file(s) you want to compress into the zip archive. For example, type “zip backup.zip home.html index.html” at a telnet command prompt to compress and archive the files called home.html and index.html into the file called backup.zip.

unzip [options] [zipfile] The unzip command extracts a zip format archive file. This command is compatible with pkunzip files from a PC. Simply type “unzip zipfile” at a telnet command prompt and replace zipfile with the name of your zip format archive file. For example, type “unzip -aL old.zip” at a telnet command prompt to extract files contained in the archive called old.zip. The “-aL” are options that are generally useful when unzipping files created on a PC.

Moving files via SSH

Often you will need to move one or more files/folders or copy them to a different location. You can do so easily using an SSH connection. The commands which you would need to use are mv (short for ‘move’) and cp (short for ‘copy’).

The mv command syntax looks like this:

mv configuration.php-dist configuration.php

By issuing the above command we will move (rename) the file configuration.php-dist to configuration.php.

You can also use mv to move a whole directory and its content:

mv includes/* ./

This will move all files (and folders) in the includes/ directory to the current working directory.

In some cases however, we will need to only update the files and move only files that were changed, which we can do by passing ‘-u’ as argument to the command:

mv -u includes/* admin/includes

The copy (cp) command works the same way as mv, but instead of moving the files/folders it copies them. For example:

cp configuration.php-dist configuration.php

The command will copy the configuration.php-dist file to configuration.php and will preserve the original file (the file will NOT be removed after it is copied).

cp also accepts various arguments:

cp -R includes/ includes_backup/

-R instructs cp to copy files recursively (for example, a whole directory). To overwrite already existing files you should use the -f argument:

cp -Rf includes/ admin/includes/