title: Weird C Compiler, getting an error "ld: duplicate symbol _main"
body: <p>I just started learning C, and wrote my hello world program:</p>
  
  <pre><code>#include &lt;stdio.h&gt;
  main()
  {
      printf("Hello World");
      return 0;
  }
  </code></pre>
  
  <p>When I run the code, I get a really long error:</p>
  
  <pre><code>Apple Mach-O Linker (id) Error
  
   Ld /Users/Solomon/Library/Developer/Xcode/DerivedData/CProj-cwosspupvengheeaapmkrhxbxjvk/Build/Products/Debug/CProj normal x86_64
          cd /Users/Solomon/Desktop/C/CProj
          setenv MACOSX_DEPLOYMENT_TARGET 10.7
          /Developer/usr/bin/clang -arch x86_64 -isysroot /Developer/SDKs/MacOSX10.7.sdk -L/Users/Solomon/Library/Developer/Xcode/DerivedData/CProj-cwosspupvengheeaapmkrhxbxjvk/Build/Products/Debug -F/Users/Solomon/Library/Developer/Xcode/DerivedData/CProj-cwosspupvengheeaapmkrhxbxjvk/Build/Products/Debug -filelist /Users/Solomon/Library/Developer/Xcode/DerivedData/CProj-cwosspupvengheeaapmkrhxbxjvk/Build/Intermediates/CProj.build/Debug/CProj.build/Objects-normal/x86_64/CProj.LinkFileList -mmacosx-version-min=10.7 -o /Users/Solomon/Library/Developer/Xcode/DerivedData/CProj-cwosspupvengheeaapmkrhxbxjvk/Build/Products/Debug/CProj
  
      ld: duplicate symbol _main in /Users/Solomon/Library/Developer/Xcode/DerivedData/CProj-cwosspupvengheeaapmkrhxbxjvk/Build/Intermediates/CProj.build/Debug/CProj.build/Objects-normal/x86_64/helloworld.o and /Users/Solomon/Library/Developer/Xcode/DerivedData/CProj-cwosspupvengheeaapmkrhxbxjvk/Build/Intermediates/CProj.build/Debug/CProj.build/Objects-normal/x86_64/main.o for architecture x86_64
      Command /Developer/usr/bin/clang failed with exit code 1
  </code></pre>
  
  <p>I am running xCode</p>
  
  <p>Should I reinstall DevTools?</p>