Command Line Unix for Information Professionals In web administration or information management work, I may be called upon, as an Information Professional, to maneuver in a Unix context from the command line. Mastering basic Unix commands will enable me to better understand information architecture, the structural formation and foundation of communal information environments, and to make sense of user behavior in an IT milieu. Demystifying the underpinnings of information architecture can only be a positive step in my development of IT fluency, rendering me less anxious and more empowered whether delving into the substructure of the web or just discussing the details with technical services. Each of the following slides contains a Unix command in black text accompanied by the assignment direction in large white text, followed by an explanation of the purpose and practical usefulness of that command. A demonstrative screenshot of the command in action is included with each one.

Login Securely connects the user to the server. Successful login shows the date of the user’s last login.

ls List files in the Root Directory Command shows all files in current directory. Verifies whether user’s position is in the desired directory and demonstrates whether a directory or file has been made, copied or deleted correctly.

cd Move into one of the directories Allows user to enter a directory in order to view and manipulate its contents. Such movement also permits the deletion of a directory where user is not currently located.

cd.. Move back to Root Directory Allows user to navigate between directories and move upward/backward in the directory listings hierarchy.

mkdir Make a new directory Allows the user to create a new directory. A directory in this setting functions as basically a container for files.

cd 560demo Move into the new directory Change directory (cd) is an important navigational tool, allowing the user to move between directories as access is needed.

history Display your last 10 commands Handy mechanism for recalling and repeating previous commands from the current session. User may also wish to recycle a previous command yet modify it in some way; this permits her to review the details.

date Display the current date Lists the date and time read from the kernel clock. Practical feature if user is in a different time zone from the server or just wishes to check the time.

who Show users logged in to the server Displays a list of users and where they are coming from (by ports). Practical for a user attempting to locate or contact another user.

cal Display current month calendar Convenient, on-demand feature which the user may access for planning and review.

rmdir Delete directory created in slide 5 Allows the user to permanently eliminate a directory from the system. Here shown with an “ls” command to demonstrate the absence of the file 560demo after the “rmdir 560demo” commandline.

ls –l Show a list of files with their assigned permissions Lists files in “long format,” which contains lots of useful information including who has authority to read, write, and/or execute each file.

The letters d r w x r What do they mean? d = directory r = read w = write x = execute d = directory r = read w = write x = execute These letters identify who has authority to read, write and execute files. The “d” indicates the filetype to which the permissions relate. The other three always appear in order, rwx, in subsets of three. The first set refers to the user class (account owner), the second set to the group class (defined internally), and the third to the others class (the public, external users). In the example above, I, mewickham, as the account owner, have exclusive read, write, and execute permissions to my mail directory.

grep Search for a specific word within a file Stands for “ g lobally search a r egular e xpression and p rint.” Permits a user to search a text file for all instances of a certain sequence.

exit Log out of the system Command causes the shell to terminate the user’s current session.

cal [year] Show a 12-month calendar of a specific year Assists the user in looking backward or forward as needed. Another version of the “cal” command permits the listing of a single month within any year.

wc [filename] How many lines, words & characters in a file Very practical if one wants to check if the number of code lines has changed between an original version of a file and a newer update.

whoami Display your username Although at first glance this command seems less than useful, it could be essential if multiple users are sharing a terminal or office and one neglects to properly exit his session.