Linux: A Sort User Manual

Prof. Teodor Rus (rus@cs.uiowa.edu)

Using a Linux Machine

How do I log in to my Linux account ?


Answer:

  • If you are using a machine in the department laboratory, at the welcome screen, you will be asked for your user name. Enter your user name. Then you will be asked for your password. Once you enter that you will be logged in.
  • If you are trying to log in from outside the department. Use ssh. The easiest way is to type at the command prompt:
    ssh username@linux.cs.uiowa.edu
    Then you shall be prompted for your password. Enter that and you shall be logged in.
    • If you have any other remote login client other than ssh, you can use that too provided you know how to use it. The machine you need to log in to is 'linux.cs.uiowa.edu'. For authentication you need to enter your user name and password again.

    How do I compile a program ?


    First, click on the terminal icon to get to the terminal. At the command prompt, type the following command
    gcc [-o output] filename.c
    where filename.c is your source C file. -o output is an optional parameter which is the name you want to give to the executable program. If specified, the output file 'output' is produced as the executable program, otherwise 'a.out' is the executable program generated by C compiler. Of course this happens if no syntax errors are discovered in your C program.

    How do I execute the program ?


    After C compiler has produced the 'output or 'a.out' as a result of compilation you can execute your program by typing
    './output parameter1 parameter2 ...'
    if you named your executable 'output' or
    './a.out parameter1 parameter2 ...'
    if you let the compiler to generate the default 'a.out' as executable.
    If you want to use the executable name "output" or 'a.out' rather than "./output" or './a.out' type in your .schrc file the command:
    set path = ( $path . )

    Note 1


    parameter1 parameter2 ... is the list of 0 or more parameters or command line arguments.

    Note 2


    You have to type './' before an executable file name because for security reasons you do not have the privilege to execute files from your login.

    How do I compile multiple files ?

    This is similar to compiling a single file. Just list the files you wish to compile separated by space. For e.g. to compile 2 files file1.c and file2.c type the following at the command prompt
    gcc -o output file1.c file2.c

    How to find more information about commands ?

    Simply type the following at the command prompt.
    man 'commandname'
    For example, to find out more about gcc type
    man gcc