title: C++ program compilation fails in Ubuntu, but works in MacOSX
body: <p>Hi I've a program written in C++. When I compile it in Mac terminal with g++ compiler, it compiles and runs. But when I compile the same C++ program in Ubuntu terminal with g++ compiler, it Fails. I don't know why it happens.</p>
  
  <p>g++ compiler version in Ubuntu is 4.7.3.</p>
  
  <p>Here is my code sample </p>
  
  <pre><code>#include &lt;iostream&gt;
  
  using namespace std;
  
  #define IXSIZE 400
  #define IYSIZE 400
  #define IZSIZE 3
  
  void putbyte(FILE *outf, unsigned char val)
  { 
      unsigned char buf[1]; 
  
      buf[0] = val; 
      fwrite(buf,1,1,outf); 
  } 
  
  void putshort(FILE *outf, unsigned short val) 
  { 
      unsigned char buf[2]; 
  
      buf[0] = (val&gt;&gt;8); 
      buf[1] = (val&gt;&gt;0); 
      fwrite(buf,2,1,outf); 
  } 
  </code></pre>
  
  <p>I get following error</p>
  
  <p><code>seperate.cpp: In function ‘void putbyte(FILE*, unsigned char)’:
  seperate.cpp:23:21: error: ‘fwrite’ was not declared in this scope
  seperate.cpp: In function ‘void putshort(FILE*, short unsigned int)’:
  seperate.cpp:32:21: error: ‘fwrite’ was not declared in this scope
  seperate.cpp: In function ‘int putlong(FILE*, long unsigned int)’:
  seperate.cpp:43:28: error: ‘fwrite’ was not declared in this scope
  seperate.cpp: In function ‘short unsigned int getshort(FILE*)’:
  seperate.cpp:49:22: error: ‘fread’ was not declared in this scope
  seperate.cpp: In function ‘long int getlong(FILE*)’:
  seperate.cpp:56:22: error: ‘fread’ was not declared in this scope
  seperate.cpp: In function ‘int main(int, char**)’:
  seperate.cpp:88:11: error: ‘stderr’ was not declared in this scope
  seperate.cpp:88:69: error: ‘fprintf’ was not declared in this scope
  seperate.cpp:89:9: error: ‘exit’ was not declared in this scope
  seperate.cpp:93:30: error: ‘fopen’ was not declared in this scope
  seperate.cpp:95:11: error: ‘stderr’ was not declared in this scope
  seperate.cpp:95:61: error: ‘fprintf’ was not declared in this scope
  seperate.cpp:96:9: error: ‘exit’ was not declared in this scope
  seperate.cpp:101:22: error: ‘fgetc’ was not declared in this scope
  seperate.cpp:114:18: error: ‘SEEK_CUR’ was not declared in this scope
  seperate.cpp:114:26: error: ‘fseek’ was not declared in this scope
  seperate.cpp:126:38: error: ‘fread’ was not declared in this scope
  seperate.cpp:131:12: error: ‘fclose’ was not declared in this scope
  seperate.cpp:138:25: error: ‘fopen’ was not declared in this scope
  seperate.cpp:141:11: error: ‘stderr’ was not declared in this scope
  seperate.cpp:141:54: error: ‘fprintf’ was not declared in this scope
  seperate.cpp:142:9: error: ‘exit’ was not declared in this scope
  seperate.cpp:153:36: error: ‘fwrite’ was not declared in this scope
  seperate.cpp:162:11: error: ‘stderr’ was not declared in this scope
  seperate.cpp:162:54: error: ‘fprintf’ was not declared in this scope
  seperate.cpp:163:9: error: ‘exit’ was not declared in this scope
  seperate.cpp:174:36: error: ‘fwrite’ was not declared in this scope
  seperate.cpp:183:11: error: ‘stderr’ was not declared in this scope
  seperate.cpp:183:54: error: ‘fprintf’ was not declared in this scope
  seperate.cpp:184:9: error: ‘exit’ was not declared in this scope
  seperate.cpp:195:36: error: ‘fwrite’ was not declared in this scope
  dfo@ubuntu:~/Desktop/abc-master$ g++ -v
  </code></p>