Introduction to Fortran and Fortran Compiling

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Introduction to Fortran and Fortran Compiling
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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

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Logging into the system using ssh

• Logging into the system from Windows
• Start the secure shell client Start-gtPrograms-gtS
  SH Secure Shell-gtSecure 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_at_HostName
• Enter your password
• If you are a windows user and you want to
  download ssh
• Go to IT Helpdesk _at_ http//www.olemiss.edu/helpde
  sk/resources.htmlsoftware and click on the SSH
  Secure Shell 3.1 link.
• If you are a Unix user, ssh will come with the
  operating system

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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
• cab
• write (,) 'The sum of the numbers you entered
  is', c
• stop
• end

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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

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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
• Suns Forte f90 on willow

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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

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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

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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

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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

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Willow

• Suns 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.

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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

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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.

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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.

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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_at_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.