title: implicit declaration of function 'get_string'
body: <p>I get the following error </p>
  
  <pre><code>cc     string.c   -o string
  string.c:7:16: warning: implicit declaration of function 'get_string' is invalid in C99
        [-Wimplicit-function-declaration]
          string name = get_string();
                        ^
  string.c:7:9: warning: incompatible integer to pointer conversion initializing 'string' (aka 'char *')
        with an expression of type 'int' [-Wint-conversion]
          string name = get_string();
                 ^      ~~~~~~~~~~~~
  2 warnings generated.
  ld: can't write output file: string for architecture x86_64
  clang: error: linker command failed with exit code 1 (use -v to see invocation)
  make: *** [string] Error 1
  </code></pre>
  
  <p>when I try to</p>
  
  <pre><code>make string
  </code></pre>
  
  <p>the code of string.c:</p>
  
  <pre><code>  1 #include &lt;stdio.h&gt;
    2 #include &lt;cs50.h&gt;
    3 
    4 int main(void)
    5 {
    6         printf("Name: ");
    7         string name = get_string();
    8         printf("hello, %s\n", name);
    9 
   10 }
  </code></pre>
  
  <p>The code is identical to the course on Week1.</p>
  
  <p>Bare in mind that i have downloaded the cs50.h and installed it as per instructions from the CS50 library manual for OSX system.</p>