Editing

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Editing Compiling UNIX vs. IDE and an Intro to
Architecture
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Outline

• Announcements
• Homework I on web, due Fri., 5PM by e-mail
• Basic computer architecture
• Creating code
• Compiling code
• Integrated Development Environments

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Development Process

• Design
• Specification
• Build Prototype
• Implementation write the code
• Build Get it to compile and run
• Debug I find and fix syntax errors
• Debug II find and fix semantic errors (testing)
• Improve performance through tuning or re-design

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Build Process

• Write code
• Pass to compiler
• Compiler creates an executable--a binary file
  with low-level instructions equivalent to your
  high-level program
• Run the executable

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Compiling Linking

• Compiling consists of two steps
• Translating high-level language to machine code
• Many ways to translate same commands
• Some ways may have better performance
• Linking bits of machine code together to form an
  executable
• Even simple programs are not self contained
• You can call routines like sin, printf, or
  write but you dont have to include code for
  these functions in your program
• Rather, built-in functions have already been
  translated and are stored in object files
  somewhere on the system
• Compiler must get the machine code and bundle
  with your executable

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Compiling Linking
cc prog.c -oprog
Transnslation
Link
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Basic Development on UNIX

• A note on UNIX
• UNIX is a powerful, elegant, and simple OS
• For many years, UNIX systems were THE systems for
  scientific work
• Windows is eating away, but UNIX systems are
  still common
• I will typically discuss UNIX tools first and
  then examine analogous tools on Windows
• The UNIX tools are typically more general and
  were the inspiration for the Windows analogs

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Basic Development on UNIX

• First thing we need is a text editor
• vi--terminal editor. Very basic editor that you
  control solely through the keyboard (no mousing)
• useful for fixing small bugs, editing input files
• I wouldnt want to write more than a few lines,
  though
• Emacs--classic UNIX word processor. Lots of
  people love emacs, but Im not one of them
• NEdit--worlds greatest text editor
• Mac/PC like interface,
• good syntax highlighting (can be easily modified
  and customized)
• Efficient searching/replace (possible to use
  regular expressions)
• column cut and paste!

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Basic Development on UNIX

• Next, we need to compile
• Compilers are specific to
• programming languages (sort of)
• Operating Systems/processors (definitely)
• For a given language/system combination there are
  often several compilers
• differ by price GNU vs. commercial
• differ by performance

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Basic Development on UNIX

• Compiling on UNIX
• cc ltoptionsgt ltcode filesgt -oltexecutable namegt
• compiler name might change (gcc, cc, f77, f90),
  but the format is usually the same
• typical options
• -o name the executable (otherwise, a.out)
• -O perform some basic performance optimizations
• -O2 perform some more dramatic optimizations
• -c compile to object code (dont link)
• -g enable debugging
• -l ltnamegt link to library libltnamegt.a
• -w inhibit warnings

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Basic Development on UNIX

• Running the program
• just type the name (assumes . is in path)
• if that doesnt work, type ./name

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Basic Development on Windows

• Editors
• Free stuff like Notepad, Wordpad
• NEdit
• MSWord (but why?)
• Compilers
• most will work from a DOS prompt in a UNIX-like
  fashion
• key difference is that you use /ltoption rather
  than -ltoptiongt

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Basic Development on Windows

• Although you can do things from a DOS prompt,
  most Windows programming is done in an Integrated
  Development Environment (IDE)
• CodeWarrior
• VisualStudio
• Also ProjectBuilder (Mac), KDev (Linux)
• What are they integrating?
• combine editor, compiler, and debugger

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IDEs

• Much easier to use, just edit and push a button
  to compile and run
• can often click on compiler error messages and go
  right to the line
• set compiler options through menus
• Main disadvantage disconnected from compiler
• often, finding compiler options is hard and
  usually just like the command line
• documentation can be poor