Introduction to Fortran and Fortran Compiling

1. Introduction to Fortran and Fortran Compiling

2. Outline Surfing www.mcsr.olemiss.edu website Logging into the system via ssh Basic Structure and Syntax of Fortran A quick glance on PICO editor More detailed look on compilers and compilingcommands Application of Fortran Compiling

3. Logging into the system using ssh Logging into the system from Windows: Start the secure shell client: Start->Programs->SSH Secure Shell->Secure Shell Client Connect to willow: From the secure shell window, click Quick Connect. Then, from the Connect to Remote Host pop-up window, enter: Hostname : HostNameUser Name : UserName Click Connect. Logging into the system from Unix: Start the Terminal: Finder Utilities  Terminal Type the following command: ssh UserName@HostName Enter your password If you are a windows user and you want to download ssh; Go to IT Helpdesk @ http://www.olemiss.edu/helpdesk/resources.html#software and click on the SSH Secure Shell 3.1 link. If you are a Unix user, ssh will come with the operating system

4. Simple Fortran Program c This program adds two numbers and displays the result program add double precision a,b,c write(*,*) 'Input two numbers (include a decimal point)' read (*,*) a,b c=a+b write (*,*) 'The sum of the numbers you entered is', c stop end

5. The PICO Editor General Command Write editor contents to a file [Ctrl] o Save the file and exit pico [Ctrl] x Spell Check [Ctrl] t Justify the text [Ctrl] j Moving around in your file Move one character to the right [Ctrl] f or right arrow key Move one character to the left [Ctrl] b or left arrow key Move up one line [Ctrl] p or up arrow key Move down one line [Ctrl] n or down arrow key

6. More detailed look into Compilers and Compiling commands Fortran Compilers at UM/MCSR: MIPSPro Fortran Compilers, version 7.4, on sweetgum Portland Group and MPICH Fortran compilers on mimosa Intel Fortran Compilers(7.1, 8.0 and 9.0) on redwood GUI g77 on willow Sun’s Forte f90 on willow

7. Sweetgum MIPSPro Fortran Compilers, version 7.4 To compile with f77 on sweetgum, enter: f77 filename.for To compile with f90 on sweetgum, enter: f90 filename.for

8. Mimosa Portland Group and MPICH Fortran compilers To compile with the MPICH Fortran compilers, enter: /usr/local/apps/pgi-5.2/linux86/5.2/bin/pgf77 filename.for To compile with the PGI SDK compilers, enter: /usr/local/apps/pgi-6.1/linux86/6.1/bin/pgf90 filename.for

9. Redwood Intel Fortran Compilers(7.1, 8.0 and 9.0) Before using the Fortran Compiler on redwood, you must first load the appropriate Intel compiler module. Then, to compile: ifc filename.for if using the 7.1 compiler ifort filename.for if using the 8.0 or 9.0 compilers

10. Loading the appropriate Intel Compiler Module Several versions/builds of Intel compilers are available on redwood. To compile, you must first pick which compiler version module you want to load, then load it. Before you can use the module command, you must source the correct setup file for your shell. . /usr/share/modules/init/sh (if using ssh) (There should be a space between . and /opt) Then you use the module command: module list (to see if any other versions of compiler modules are loaded) module purge (to unload any other versions of compiler modules) module list (to verify that other versions were successfully unloaded) module avail (to see what versions of compiler modules are available to load) For example, to load the latest 9.1 version of the F Compilers: module load f91 module list These are the names of the modules and the compiler versions they correspond to: intel-compilers.7.1.037 for fortran 7.1 intel-compilers.8.0.042 for fortran 8.0 intel-compilers.8.0.046 for fortran 8.0 intel-compilers.9.0.027 for fortran 9.0 intel-compilers.9.1.046 for fortran 9.1

11. Willow Sun’s Forte f90 To compile with f90, enter: f90 filename.for If there are no compilation errors this creates an executable file called a.out. To execute the Fortran program, enter: ./a.out. GUI g77 To compile with g77, enter: g77 filename.for If there are no compilation errors this creates an executable file called a.out. To execute the Fortran program, enter: ./a.out.

12. More about Compiling Commands If there are no compilation errors, the previously mentioned Fortran Commands create an executable file called a.out. To execute the Fortran program, enter: ./a.out. To create an executable file with another filename, use the –o flag, for example: f90 –o exefilename filename.for For more information about Fortran compilers, Go to: www.mcsr.olemiss.edu SoftwareFortran

13. How to run a compiled files • The compiling commands create an executable file known as a.out unless specified otherwise. • To execute your program, type: ./a.out and press Enter.

14. MCSR Fortran Compilers MCSR's Fortran compilers and platforms are available for instructional or research use for all students, faculty, and staff of Mississippi's eight public universities. Users should decide which compiler is best suited for their application. Compilers on SUN are for fast jobs with a quick turn around, while compilers on sweetgum and magnolia are designed for larger, more computationally intensive jobs.

15. MCSR Accounts MCSR is pleased to provide free computer accounts on redwood, sweetgum, and mimosa for any student, faculty, or research staff member at any of Mississippi's 8 publicly funded universities. If you can't access an existing account, please e-mail assist@mcsr.olemiss.edu or call one of the consultants at 662-915-7206. You may request a password reset from the MCSR Online Account Manager.