**Contents**

[[!toc levels=2]]

#  Startup & Shutdown 

  * Shutdown the machine immediately and reboot 
    
    shutdown -r now

  * Shutdown the machine and immediately power off (for ATX hardware, you will need to install and enable the [[!template id=man name="apm" section="8"]] support in kernel: see [[How to poweroff at shutdown]] for details) 

    shutdown -p now

  * Shutdown the machine and halt afterwards (but keep the power on) 

    shutdown -h now

#  File & Directory Operations 

  * Find out what directory you are in 
    
    pwd

  * List contents of current working directory 
    
    ls

  * Copy a file to a new file with a different name 
    
    cp foobar.txt barfoo.txt

  * Remove a file (delete it) 
    
    rm foobar.txt

  * Remove an ""empty"" directory. 
    
    rmdir mydir

  * Recursively remove a directory (be careful with this, if you mess up, you can easily wipe out your whole system). This will remove the directory and all the files and subdirectories it contains, provided you have permissions. 
    
    rm -rf mydir

#  Using Archives 

  * Create a ""tar"" archive with the contents of a directory displaying each file and directory as tar runs verbosely. 
    
    tar cvf my_archive.tar some_directory

The same using pax: 
    
    pax -w -v -f my_archive.tar some_directory

  * Extract a ""tar"" archive to the current directory displaying each file and directory as tar runs verbosely. 
    
    tar xvf my_archive.tar

The same using pax: 
    
    pax -r -v -f my_archive.tar

  * Compress a file with gzip using maximum (slowest) compression 
    
    gzip -9 foobar.txt

  * Compress a file with bzip2 using maximum (slowest) compression. Bzip generally compresses files better at the cost of greater time during the compression phase. The archives it creates generally de-compress at the same speed as gzip. 
    
    bzip2 -9 foobar.txt

#  User Operations 

  * Add a new user and create their home directory 
    
    useradd -m jsmith

  * Change a user's default shell 
    
    chsh -s /path/newshell jsmith

or 

    chpass -s /bin/ksh jsmith
    

#  Package Operations (pkgsrc) 

  * Add a binary package 
    
    pkg_add my_binary_package.tgz

  * List all (installed) packages 
    
    pkg_info

  * List all files that are part of a directory 
    
    pkg_info -L the_package_name

  * Delete a package 
    
    pkg_delete the_package_name

  * Create a binary package file from an already installed package (this requires the **pkg_tarup** tool from pkgsrc which lives under the **pkgtools** subdirectory.) 
    
    pkg_tarup the_package_name

#  Advanced Command Line Recipes 

  * Create a binary package for every single installed package on the system and place them all in the current directory. 
    
    
    for pkg in `pkg_info -e "*" | sort`; do echo "Packaging $pkg"; pkg_tarup -d . $pkg 1>/dev/null; done