title: conio.h: No such file or directory using Linux?
body: <p>I'm getting this compiling error for my program when I try to compile/run it on Linux.</p>
  
  <pre><code>program7.c:9:18: conio.h: No such file or directory
  make: *** [program7] Error 1
  </code></pre>
  
  <p>I don't know what function is causing this error in Linux. I read details about how <code>conio.h</code> is not part of the C standard library.</p>
  
  <p>My code:</p>
  
  <pre><code>#include&lt;stdio.h&gt;
  #include&lt;conio.h&gt;
  #include&lt;math.h&gt;
  
  int add(int a,int b); // declaration of add function                                                       
  int multiply(int a,int b); // Prototype of multiply function                                               
  long int power(int num,int pow); // Prototype of power function                                            
  int sumOfPowers(int z, int y); // Prototype of Sum of power function                                       
  int calculateGcd(int x,int y); // Prototype of GCD function                                                
  
  int main(){
          int num1,num2;
          int sum,mul,total,gcd;
          long int pow;
  
          printf("Enter two positive integers, separated by a space, the first smaller than the second: ");
          scanf("%d %d",&amp;num1,&amp;num2);
  
          // Get Calculated sum from add function and assign to sum                                          
          sum = add(num1,num2);
          printf("\nThe sum of %d to %d =  %d\n",num1,num2,sum); // print sum output                         
  
          // Get Calculated multiplication from multiply function and assign to mul                          
          mul = multiply(num1,num2);
          printf("\nThe product of %d to %d =  %d\n",num1,num2,mul); // print multiply output
  
          // Get power from power function and assign to pow                                                 
          pow = power(num1,num2);
          printf("\n%d to power of %d = %ld \n",num1,num2,pow); // print pow output
          total = sumOfPowers(1,num2);
          printf("\n The sum of powers of 2 from 1 to 2^%d = %d\n",num2,total); // print total output
  // Get gcd value from calculateGcd function and assign to gcd                                      
          gcd = calculateGcd(num1,num2);
          printf("\nThe GCD of %d and %d = %d\n",num1,num2,gcd); // print pow output
  }
  
  // Add function to add two number                                                                          
  int add(int a,int b){
          if(b&lt;=a){
                  return;
          }
          while(b&gt;=a){
              return b+add(a,b-1);
          }
  }
  
  // Multiply function to multiply two number                                                                
  int multiply(int a,int b){
          if(a&gt;b){
                  return;
          }
                  while(a&lt;b){
                  return a*multiply(a+1,b);
                  }
  }
  
  // Powet function to calculate power of two numbers                                                        
  
  int i=1;
  long int cal=1;
  long int power(int num,int pow){
        if(i&lt;=pow){
             cal=cal*num;
            power(num,pow-1);
        }
        else
        return cal;
    }
  
  int calculateGcd(int x,int y){
       while (x != y)
      {
          if (x &gt; y)
          {
              return calculateGcd(x - y, y);
          }
          else
          {
              return calculateGcd(x, y - x);
          }
      }
      return x;
  }
  
  // Calculate the sum of powers from x to y                                                                 
  int total = 1;
  int sumOfPowers(int z, int y){
          int new;
  
          while(z&lt;=y){
          new = pow(2,z);
          total = total + new;
          z++;
          }
  
          return total;
  }
  </code></pre>
  
  <p><strong><em>EDIT</em></strong>
  I tried removing the conio.h header all together. But I got the following error:</p>
  
  <pre><code>Undefined                       first referenced
   symbol                             in file
  pow                                 /var/tmp//cc6jlZ6f.o
  ld: fatal: Symbol referencing errors. No output written to program7
  collect2: ld returned 1 exit status
  make: *** [program7] Error 1
  </code></pre>
  
  <p>My Makefile:</p>
  
  <pre><code>program7: program7.c
          gcc -o program7 program7.c
  </code></pre>