This document provides information on using Fortran compilers at the Mississippi Center for Supercomputing Research (MCSR). It describes how to log into the MCSR systems, write a simple Fortran program, use the PICO text editor, compile and run programs using different compilers on systems like Sweetgum, Mimosa, Redwood and Willow. The compilers include MIPSPro, Portland Group, MPICH, Intel and Sun Forte compilers. Accounts are available for students and faculty from Mississippi public universities.

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
compiling commands
 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 : HostName
User 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
 Thecompiling commands create
an executable file known as
a.out unless specified otherwise.
 Toexecute 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.