fputs is available since version 1.0.
Prototype:
number fputs(string buffer, number fd) 
Parameters
	
		
			buffer
		
		
			[in] Output string
		
	 
	
		
			fd
		
		
			[in] A valid file descriptor
		
	 
 
Description:
fputs copies buffer to the output stream fd at the current position, without the terminating null character.
Return value:
fputs returns a negative value if it is successful. 
Example
import standard.C.io
define FILENAME     "test.txt"
class Main {
     function Main() {
          var fd; 
          var buffer = "Testing fputs.";     
          // Open file for write
          if (fd = fopen(FILENAME, "w")) {               
               if (fputs(buffer, fd))
                    echo "fputs error\n";                    
               else
                    echo "fputs success\n";
               fclose(fd);
          } else
               echo "Problem opening the file\n";
          
     }
}  
Results 
fputs success