Instructions for Emacs text editor, Linux operating system, and Fortran compiler.

Overview

Emacs is a text editor used to write computer programs and scripts.  It uses a graphic user interface similar to popular windows and mac environments.  Namely, you use the mouse a lot.  It is an alternative to using VI, the line text editor that your already learned.

Versions of emacs exist that can run on linux, Windows, and MacOSX computers.  They are free.  We already have a version installed on our eidolon server, which you will access remotely using the NX Client.   For this lab, we want you all to use the emacs that is already on eidolon (namely, no need to install it on your own laptop).  If you are using your own laptop during lab, be sure to install the NX Client.   

The main reason for using emacs is when you are working in a linux environment and need to create or edit ascii text for computer programs (Fortran, C) or scripts (PERL).  

The first section of info below shows how to use emacs on a linux machine.     The second shows how to use it on our Windows machine (after which we upload the results to the linux machine).  We will focus on the only first method (emacs on a linux machine) here, but if it doesn't work for you, then try the second.

The GNU Project has created a body of free software that runs linux operating systems.  We will use the gnu Fortran Compiler in this section of the course.  In other sections we will use other gnu software.  There are versions that run on many different computers.  Again, we want you to use the gfortran compiler already installed on eidolon, so no need to install it on your own laptop.  

This guide has you use emacs to write some fortran code, then  use the gnu fortran compiler (gfortran) to compile the code into an executable object, and finally run that code under linux.

Emacs on Linux Box

Set up files and shortcuts.  While using windows explorer:

1. Create a folder called "fortran" on your Z drive of your windows machine.  This will  hold the input and output files for your program.  
2. Run your web browser (Mozilla, Firefox, IE, etc), and go to the course web site, Labs, Fortran 1.  From this page, first open the sounding ascii text input file for porthardy.txt, and view the ascii text.  
3. Put a copy of this file into your ""fortran"" folder.  
4. Do the same for the darwin.txt sounding ascii text.

Upload your fortan file and contents from the Windows machine to the linux box via secure ftp

1. Run the FileZilla program 
2. under the FileZilla "file" menu, select site manager, and then double click on "eidolon" to connect to that machine.   (If it doesn't work, its because you changed your password on eidolon.  So in the FileZilla Site Manager, enter the new password and click OK.  Then close the Site Manager window.  Open the connection to eidolon using the site icon on the toolbar.)
3. upload your "fortran" directory and its contents to eidolon
4. Don't log out of FileZilla -- instead, just minimize it.  (We might use it later, such as to back up your work from eidolon onto your local disk drive.)

Use your Windows machine as a remote terminal to the linux machine:

1. Activate the "eidolon" NX client from your Windows desktop (the icon that says eidolon under it).
   
2. Log in with your password when prompted.
3. Wait a long time, for autorun to finish.
4. Click on the "terminal" icon that is in the NX dock (along the bottom of the NX window), to run the terminal program.  You are now in Linux.

Linux review

1. type "ls" and hit return, you will see a list of files in your user directory on eidolon
2. in this file list, you should see your directly called "fortran" that you had copied from your lab computer.  (Ignore all the other stuff in your user directory, and DON'T delete it.)
3. If you had previously created a directory called "Fortran" (remember that linux is case-sensitive, so "Fortran" is different from "fortran") from earlier in the course, then carefully delete the one called "Fortran" by using linux command rm -ri Fortran  and then respond to it's yes/no questions.
4. type "cd fortran", to change directory to "fortran"
5. type "ls" again and hit return, to see a list of files inside your "fortran" directly.
6. in this file list, you should see the input files you already copied, for porthardy.txt and darwin.txt .

Run the text-editing program called emacs.

1. A powerful feature of many text editors, including emacs, is the ability to automatically color-code different parts of the fortran syntax with different colors.  This is called "syntax highlighting" and is extremely valuable when you write and debug computer programs.  However, many people are color-blind to red, for whom the syntax highlighting makes the computer program extremely hard to read.  So here are two alternative ways to open emacs depending on your preference on the color highlighting:
   .
1. For people who prefer to view their computer program as only black text, open the emacs program by double clicking the icon of an ox at the bottom of the NX client window .  
   .
2. For people who prefer to use the color highlighting of syntax, do NOT double-click the emacs ox icon.   Instead, in the Terminal window, type the linux command
     emacs wp01.f95 & 
   The extra "space ampersand" after the emacs command is nice, because it allows both the command-line terminal and the emacs editing window to both be open on your screen.  If file wp01.f95 didn't already exist, this method will automatically create it as soon as you save your work in emacs.
2. If you opened emacs without indicating which file to work on, then go to the File menu of emacs, and select Open File (which will create a New file if you don't give it an existing one to open).  Name the new file "~/fortran/wp01.f95", and save it into your "fortran" folder on the linux machine.  

1. Type the demo wind-power wp01.f95 fortran file into emacs.  Save your results periodically as you write.   You can make the emacs window larger if you wish.  Here is wp01.f95. (Note that your colors might be different than the ones shown here.)
   .
   !Estimate wind power
   program windpowermain
     write(*,*) "Welcome to Wind Power"   !welcome the user
   end program windpowermain
   .
2. Don't forget to type all the comments (starting with exclamation points) as you write the code.  Don't wait to add them later, otherwise you might loose points.  
3. If your program does not automatically highlight the different syntax in different colours, then under the Options menu of emacs, check the box for "syntax highlighting".  (Note, the colours on your screen will be different than the colours in the example above.)
4. Proofread your code, and then save it when done. 
5. Move the emacs window a bit off to the side, so you can see the terminal window.

1. in the NX terminal window, type:
2. "gfortran wp01.f95 -o runwp01", and hit return
3. If the compiler found any errors, it will automatically display a lot of error messages.  If it compiled successfully, you will just see the usual linux prompt.
4. type "ls" and hit return.  Your list of files should now include the new file "runwp01".  This is your executable program.

1. type "./runwp01" without the quotation marks, and hit return.
2. if successful, your program will write some output to the screen, and will automatically end and display the linux prompt again.
3. Find the emacs window on your screen, and move it back to the front center where you can use it again.

1. In emacs, fix any bugs that you found while compiling or running the program, and then test by compiling and running again (see the Compile and Run steps above).
2. Enhance the wp program by adding more lines, following the examples given in class.  
3. Continue compiling, running, and debugging, and writing more of the wind power program.

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Emacs on Windows Machine

(Skip this section, unless you couldn't get Emacs to work directly on the linux machine.)

Set up files and shortcuts.  While using windows explorer:

1. Find the program "emacs" from the list of programs, and put a shortcut to it on your desktop.
2. Create a folder called "fortran" on your Z drive.  This will hold your fortran input and output.  
3. Run your web browser (Mozilla, Firefox, IE, etc), and go to the course web site, Labs, Fortran 1.  From this page, first open the sounding ascii text input file for Port Hardy, and view the ascii text.  
4. Put a copy of this file into your "fortran" folder.  
5. Do the same for the Dawson sounding ascii text.

Run the text-editing program called emacs.

1. From your desktop, run "emacs" by double clicking on it.
2. Ignore the text that appears in the window.  Instead, go to the File menu of emacs, and select Open File (which will create a New file if you don't give it an existing one to open).  Name the new file "wp01.f95", and save it into your "fortran" folder on your Z drive.  

1. Type the demo wind-power fortran file into emacs.  Follow the example given above.   Save your results periodically as you write.  
2. Don't forget to type all the comments (starting with exclamation points) as you write the code.  Don't wait to add them later, otherwise you might loose points.  
3. Proofread your code, and then save it when done.  (Note, it is being saved on your Windows machine, in the Z drive.)
4. Minimize the emacs program, but don't quit it.

Upload your FORTRAN code from the Windows machine to the linux box via secure ftp

1. Run the FileZilla program
2. connect to eidolon
3. upload your "fortran" directory and its contents "wp01.f95" to eidolon
4. Don't log out of FileZilla -- instead, must minimize it.

1. Activate the NX client from your Windows desktop (the icon that says eidolon under it).
   
2. Log in with your password when prompted.
3. Wait a long time, for autorun to finish.
4. Click on the "terminal" icon, second from the bottom left, to run the terminal program.  You are now in Linux.

1. type ""ls"" and hit return, you will see a list of files in your user directory on eidolon
2. in this file list, you should see your directly called "fortran" that you had copied from your lab computer.  (Ignore all the other stuff in your user directory, and DON'T delete it.)
3. type "cd fortran", to change directory to "fortran"
4. type ""ls"" again and hit return, to see a list of files inside your "fortran" directly.
5. in this file list, you should see your file called "wp01.f95"

1. while still using the NX terminal client to talk with eidolon, type:
2. "gfortran wp01.f95 -o runwp01", and hit return
3. If the compiler found any errors, it will automatically display a lot of error messages.  If it compiled successfully, you will just see the usual linux prompt.
4. type "ls" and hit return.  Your list of files should now include the new file "runwp01".  This is your executable program.

1. type "./runwp01" without the quotation marks, and hit return.
2. if successful, your program will write some output to the screen, and will automatically end and display the linux prompt again.
3. Minimize the NX terminal.

1. Expand the minimized "emacs" program
2. Fix any bugs that you found while compiling or running the program, and then upload using FileZilla, and test by compiling and running again (see the Compile and Run steps above).
3. Enhance the wp program by adding more lines, following the examples given in class.  
4. Continue compiling, running, and debugging, and writing more of the wp program.

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Emacs on a Macintosh

Don't bother with Emacs on a Mac.  Instead, use the much nicer program called TextWrangler.  It is also free.

Also, instead of FileZilla, and nice program for file transfer to/from the Mac is called  CyberDuck.  Also free.